NAT'L INST. OF STAND & TECH

AlllOt. T7flE51

National Bureau

of Standards

Computer Science

and Technology

NBS

PUBLICATIONS

NBS Special Publication 500-111

Proceedings of the National Bureau of

Standards/National Security Agency

Workshop on

Standardization Issues for Optical

Digital Data Disk (OD^) Technology

Held at National Bureau of Standards,

Gaithersburg, Maryland, June 1-3, 1983
NATIONAL BUREAU OF STANDARDS

The National Bureau of Standards' was established by an act ot Congress on March 3, 1901. The Bureau's overall goal is to strengthen and advance the Nation's science and technology

and facilitate their effective application for public benefit. To this end, the Bureau conducts

research and provides: (1) a basis for the Nation's physical measurement system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau's technical work is per- formed by the National Measurement Laboratory, the National Engineering Laboratory, and

the Institute for Computer Sciences and Technology.

THE NATIONAL MEASUREMENT LABORATORY provides the national system of

physical and chemical and materials measurement; coordinates the system with measurement

systems of other nations and furnishes essential services leading to accurate and uniform

physical and chemical measurement throughout the Nation's scientific community, industry,

and commerce; conducts materials research leading to improved methods of measurement,

standards, and data on the properties of materials needed by industry, commerce, educational

institutions, and Government; provides advisory and research services to other Government

agencies; develops, produces, and distributes Standard Reference Materials; and provides

calibration services. The Laboratory consists of the following centers:

Absolute Physical Quantities^ — Radiation Research — Chemical Physics —

Analytical Chemistry — Materials Science

THE NATIONAL ENGINEERING LABORATORY provides technology and technical ser- vices to the public and private sectors to address national needs and to solve national problems; conducts research in engineering and applied science in support of these efforts; builds and maintains competence in the necessary disciplines required to carry out this research and technical service; develops engineering data and measurement capabilities;

provides engineering measurement traceability services; develops test methods and proposes

engineering standards and code changes; develops and proposes new engineering practices;

and develops and improves mechanisms to transfer results of its research to the ultimate user. The Laboratory consists of the following centers:

Applied Mathematics — Electronics and Electrical Engineering^ — Manufacturing

Engineering — Building Technology — Fire Research — Chemical Engineering^

THE INSTITUTE FOR COMPUTER SCIENCES AND TECHNOLOGY conducts

research and provides scientific and technical services to aid Federal agencies in the selection, acquisition, application, and use of computer technology to improve effectiveness and

economy in Government operations in accordance with Public Law 89-306 (40 U.S.C. 759), relevant Executive Orders, and other directives; carries out this mission by managing the Federal Information Processing Standards Program, developing Federal ADP standards

guidelines, and managing Federal participation in ADP voluntary standardization activities; provides scientific and technological advisory services and assistance to Federal agencies; and

provides the technical foundation for computer-related policies of the Federal Government.

The Institute consists of the following centers:

Programming Science and Technology — Computer Systems Engineering.

'Headquarters and Laboratories at Gailhersburg, MD, unless otherwise noted; mailing address Washington, DC 20234. 'Some divisions within the center are located at Boulder, CO 80303.
Computer Science

and Technology

KATIOMAJL BUF.EAir OF ST.r-.'.DAnOS LIBR/.nV QC

NBS Special Publication 500-1 1

1

Soo

Proceedings of the National Bureau of

Standards/National Security Agency

Workshop on

0

Standardization Issues for Optical

Digital Data Disk (OD^) Technology

Jean B. Freedman, Editor

System Components Division

Institute for Computer Sciences and Technology

National Bureau of Standards

Washington, DC 20234

Major Contributors: Mark W. Goldberg (National Security Agency)

W. Mike Deese (Storage Technology Corporation)

Edward LaBudde (LaBudde Engineering Corporation)

Cosponsored by: National Security Agency

Department of Defense

Ft. George G. Meade, MD 20756

U.S. DEPARTMENT OF COMMERCE

Malcolm Baldrlge, Secretary

National Bureau of Standards

Ernest Ambler, Director

Issued April 1984
Reports on Computer Science and Technology

The National Bureau of Standards has a special responsibility within the Federal

Government for computer science and technology activities. The programs of the

NBS Institute for Computer Sciences and Technology are designed to provide ADP

standards, guidelines, and technical advisory services to improve the effectiveness

of computer utilization in the Federal sector, and to perform appropriate research

and development efforts as foundation for such activities and programs. This

publication series will report these NBS efforts to the Federal computer community as

well as to interested specialists in the academic and private sectors. Those wishing

to receive notices of publications in this series should complete and return the form

at the end of this publication

Library of Congress Catalog Card Number: 84-601025

National Bureau of Standards Special Publication 500-1 1

1

Natl. Bur. Stand. (U.S.). Spec. Publ. 500-1 11, 238 pages (Apr. 1984)

CODEN: XNBSAV

U.S. GOVERNMENT PRINTING OFFICE

WASHINGTON: 1984

For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402
TABLE OF CONTENTS

Page

INTRODUCTION TO THE PROCEEDINGS OF THE NATIONAL

BUREAU OF STANDARDS (NBS)/NATIONAL SECURITY AGENCY

(NBA) WORKSHOP ON STANDARDIZATION ISSUES FOR OPTICAL

DIGITAL DATA DISK (0D3) TECHNOLOGY

Jean Freedman, National Bureau of Standards 1 NBS/NSA Worksh<^ on Standardization Issues for 0D3 Technol<^ - Welcoming Remarks

James Burrows, National Bureau of Standards 4

NBS/NSA Workshop on Standardization Issues for OD^ Technology - Openii^ Remarks

John Riganati, National Bureau of Standards 5 NBS/NSA Workshop on Standardization Issues for OD^ Technology - Introduction to the Workshop Presentations and Discussions

Jean Freedman, National Bureau of Standards

Mark Goldberg, National Security Agency 6

1. DAY 1: Wednesday, June 1, 1983 - CHARACTERISTICS OF AN

OPTICAL MEDIA UNIT AND THE DIGITAL DATA CHANNEL

INTERFACES AS RELATED TO DRIVE PERFORMANCE 7

1.1 SESSION I PRESENTATIONS AND DISCUSSIONS - UNRECORDED OPTICAL MEDIA UNIT CHARACTERISTICS 7

1.1.1 The Cartricjfee and Disk Interfaces - Physical,

LabeUii^, and Handling

Boris Muchnik, Storage Technology Corporation 7

1.1.2 Physical & Mechanical Characteristics of an Unrecorded Optical Media Unit: Specifiable

Parameters Required for Data Interchange

Philip Scheinert, Burroughs Corporation 9

1.1.3 Optical Characteristics of a Disk/Cartridge Media

Unit

Roland Malissin, Thomson-CSF 15

1.1.4 Quality Characteristics of An Optical Disk Recording

Surface

Miguel Capote, Optical Coating Laboratory, Inc 23

1.1.5 Quality Characteristics of Digital Optical Recording

Media

Jan Verhoeven, Optical Media Laboratories 30

iii
1.1.6 Optical Digital Data Disk: Media Aims and

Potential Standardization

Noel Proudfoot, Eastman Kodak Company 38

1.2 SESSION U PRESENTATIONS AND DISCUSSIONS - RECORDED OPTICAL MEDIA UNIT CHARACTERISTICS 51

1.2.1 Effect of Disk Mechanical Runout on Data Integrity

Edward LaBudde, LaBudde Engineering

Corporation 51

1.2.2 Optical Characteristics of Recorded Media

Leonard Laub, Vision Three, Inc 53

1.2.3 Electrical Characteristics of the Disk - Data and

Servo Control

Yoshito Tsunoda, Hitachi Ltd 54

1.2.4 Data Format, Initialization, and Error Management

Di Chen, Optical Peripherals Laboratory 56

1.2.5 Recorded Characteristics - File Structure and

Labelling

Kenneth Nolan, IBM Corporation 63

1.2.6 Quality Characteristics of Optically Recorded Data

Miguel Capote, Optical Coating Laboratory, Inc 65

1.2.7 Panel Discussion: Recorded Optical Media Unit

Characteristics 72

1.3 SESSION III PRESENTATIONS AND DISCUSSIONS - OPTICAL

DIGITAL DATA TRANSFER AND COMMAND INTERFACES 75

1.3.1 Characteristics of the Host Computer I/O Interface

William Burr, National Bureau of Standards 75

1.3.2 Optical Device Level Characteristics: Which can

Help Determine Interface Selection

Robert Bender, Storage Technology Corporation 88

1.3.3 Panel Discussion: OD^ Transfer and Command

Interfaces 91

1.4 Summary: Characteristics of an Optical Media Unit and the

Digital Data Channel Interfaces as Related to Drive

Performance

Edward LaBudde, LaBudde Engineering Corporation 93

2. DAY 2: Thursday, June 2, 1983 - APPLICATIONS FOR DIGITAL

OPTICAL STORAGE AND TEST METHODS FOR DETERMINING

RELATIVE MEDIA & DATA LIFE 94

iv
2.1 SESSION I PRESENTATIONS AND DISCUSSIONS - APPLICATIONS FOR DIGITAL OPTICAL STORAGE

TECHNOLOGIES 94

2.1.1 A Large Capacity Mass Storage System

Bernard O'Lear, National Center for Atmospheric

Research 94

2.1.2 A Moderate Capacity Mass Storage System

Paul Allison, U.S. Army Materiel Development

and Readiness Command 104

2.1.3 A Lai^e Capacity Distributed Mass Storage System

Pat Savage, Shell Oil Company „ . . . 112

2.1.4 A Cartt^aphic Mapping and Data Base Management

System

Ted Albert, U.S. Geological Survey 116

2.1.5 A Mobile Platform Application for Distributed Optical

Stor^e

Jack Petruzelli, U.S. Air Force, Rome Air

Development Center 117

2.1.6 Opportunities for Document and Character Storage

in Commercial Applications

Leonard Laub, Vision Three, Inc 120

2.1.7 Perspectives of an OD^ Integrator: Office

Applications

David Fain, Integrated Automation Corporation 123

2.1.8 Technical Requirements for Document Storage

Applications

Gerry Walter, Planning Research Corporation 125

2.1.9 Optical Storage in an OEM Environment

Joseph Zajaczkowski, Sperry Corporation 127

2.1.10 Requirements for Easily Destructible Optical

Media Units

Mark Goldberg, National Security Agency 128

2.1.11 Panel Discussion: OD^ Applications and Standards

Requirements 129

2.1.12 0D3 Media Exhibit 131

2.2 SESSION II PRESENTATIONS AND DISCUSSIONS - LEGAL

AND ARCHIVAL REQUIREMENTS OF AN OPTICAL MEDIA

UNIT 132

V
2.2.1 0D3 System Considerations of Business Archival

Information

Morris Cohen, NCR Corporation 132

2.2.2 A Partial Solution to the Data Integrity Problem

Dennis Branstad, National Bureau of Standards 134

2.2.3 Medium Term, Long Term, and Archival Properties

of Phot(^aphic Materials

Peter Adelstein, Eastman Kodak Company 136

2.2.4 The Meaning and Use of "Archival"

Thomas Brown, National Archives and Records

Service (NARS) 140

2.2.5 What Constitutes a Legal Document?

Thomas Bagg, National Bureau of Standards 142

2.2.6 Panel Discussion: "What is the distinction between

legal and archival requirements for any document;

how could OD^ be used in an application that requires

both a legal and archival storage medium; how could

archivability be viewed with respect to a new

technology?" 143

SESSION III PRESENTATIONS AND DISCUSSIONS - TEST

METHODS FOR DETERMINING RELATIVE MEDIA & DATA

LIFE 144

2.3.1 Unrecorded Media - Shelf Life

Martin Levene, RCA 144

2.3.2 Recorded Media - Data Life

Louis Spruijt, Optical Media Laboratories 149

2.3.3 Test Methods for Measuring Life Expectancy of

Photc^aphic Materials

Peter Adelstein, Eastman Kodak Company 162

2.3.4 Measurement Techniques and Standards: Thin Film

Technology

Jane Clover, Optical Coating Laboratory, Inc 176

2.3.5 Accelerated Life Testing - Optical Media

Philip Scheinert, Burroughs Corporation 178

2.3.6 Summary of Media Life

Tomio Yoshida, Matsushita 182

vi
2.3.7 Panel Discussion: "What test methods could be

used for the measurement of media life? Is there a possibility of a standard test and if so, what should it be?" 184

2.4 WHAT IS A DATA INTERCHANGE STANDARD?

A Magnetic Media Example

Michael Hogan, National Bureau of Standards 186

3. DAY 3: Friday, June 3, 1983 - THE PURSUIT OF 0D3

DATA INTERCHANGE STANDARDS 191

3.1 SESSION I - PANEL DISCUSSION: WHAT 0D3 DATA

INTERCHANGE STANDARDS ARE POSSIBLE FOR THE

UNRECORDED 0D3 MEDIA UNIT?

CAN A STANDARD TEST PROCEDURE FOR UNRECORDED

MEDIA CHARACTERISTICS BE APPLIED ACROSS A

RANGE OF MEDIA? 191

3.2 SESSION n - PANEL DISCUSSION: WHAT STANDARDS

ARE POSSIBLE FOR THE 0D3 CARTRIDGE? 195

3.3 SESSION m - PANEL DISCUSSION: WHAT STANDARDS

ARE POSSIBLE FOR THE RECORDED OD^ MEDIA UNIT - DATA FORMAT, LABELLING, AND FILE STRUCTURE?

WHAT INTERFACE STANDARDS ARE POTENTIALLY

APPLICABLE TO OD^ 197

3.4 SESSION IV - PANEL DISCUSSION: WHAT STANDARDS

ARE POSSIBLE FOR OD^ CHANNEL I/O AND STORAGE

SUBSYSTEM INTERFACES? 199

3.5 SESSION V - THE PURSUIT OF OPTICAL DIGITAL DATA

INTERCHANGE STANDARDS 200

3.5.1 The Pursuit of OD^ Data Interchange Standards

Michael Deese, Storage Technology Corporation 200

3.5.2 A Cost Benefit Impact Assessment of OD^

Standardization

Marco Fiorello, Titan Systems 201

3.5.3 Timing the Pursuit of Optical Standards - When is

it Right?

Joseph Zajaczkowski, Sperry Corporation 205

3.6 The Role of NBS in the Future Development of OD^

Standards

Michael Hogan, National Bureau of Standards 206

vii
4. Appendix A. List of Symbols, Abbreviations, and Acronyms

Used in These Proceedings 208

5. Appendix B. Optical D^tal Data Disk Preliminary Glossary

of Terms 212

6. Appendix C. List of Workshop Participants 217

viii
ABSTRACT

National Bureau of Standards/National Security Agency

Workshop on Standardization Issues for

Optical Digital Data Disk (OD^) Technology

Jean B. Freedman

Editor

This report constitutes the proceedings of the National Bureau of

Standards/National Security Agency jointly-sponsored Workshop on Standardization

Issues for Optical Digital Data Disk (0D3) Technology, held in Gaithersburg,

Maryland, June 1-2-3, 1983. The objective of this workshop is to promote discussion

and interchange among current and potential OD^ users and suppliers, regarding the

prospects for 0D3 data interchange standardization.

The workshop presentations include definitions of the physical, dimensional,

optoelectrical, quality and data transfer characteristics of OD^ media, as related to

the drive performance. A range of OD^ applications and their standards'

requirements are also described. The various methods currently used for estimating

media life expectancies and the potential for standardized terminologies and

procedures for such assessments are discussed.

Many workshop participants noted that there were numerous complexities associated

with 0D3 data interchange among systems. Data interchange parameters include

the optical media sizes, their reflection and transmission characteristics, error detection and correction schemes, and numerous other parameters that are incorporated in the functional design of OD^ media and systems.

The participants also noted the timeliness and importance of OD^ data interchange

standardization activities and gave priority to the development of an optical digital

data disk lexicon. Many of the workshop participants also expressed an immediate

need for standardized test and evaluation procedures for OD^ media responses, life

expectancies, and environmental requirements.

Key words: archival storage; cartridge; computer storage media; data interchange;

data transfer interfaces; media life expectancy; optical digital data disk (OD^);

optical disk document scan applications; optical disk mass storage system

applications; optical disk systems; standardization.

ix

INTRODUCTION

These proceedings include synopses of presentations and panel discussions from the

National Bureau of Standards and National Security Agency jointly-sponsored

Workshop on Standardization Issues for Optical Digital Data Disk (OD^) Technology.

The workshop was held on June 1-2-3, 1983, in Gaithersburg, Maryland, in response

to the growing interest in the prospects for standardization of OD^ media and

systems.

A. The purpose and scope of the workshop includes the following:

(1) To examine the emerging 0D3 technologies and applications.

. Define the implementation of 0D3 technology in mass storage systems

(MSS) and document scan systems.

. Discuss the test methods and techniques for determining life

expectancies of unrecorded and recorded OD^ media.

. Discuss the system relationships of OD^ media, drive, and data channel

interfaces.

(2) To determine the potential directions for standardization of OD^ media

and systems.

. Specify the physical, dimensional, optoelectrical, and data transfer

characteristics that are required for OD^ data interchange.

. Examine the data interchange problems associated with OD"^ technology.

. Assess the impacts of standards in a field consisting of emerging optical

media and systems.

. Explore where standards could be useful for OD^ unrecorded and

recorded media, cartridge, and data transfer/command interfaces.

. Describe the role of the Institute for Computer Sciences and Technology

(ICST) at the National Bureau of Standards (NBS) in the development of

standards, and their participation in standards committee activities.

(3) To provide technical information and guidance towards the development of

future standards, based on the expressed needs of users and suppliers.

. Establish the need for the development of standardized vocabularies and

test procedures—specifically for use in the evaluation of OD^ unrecorded

media life and recorded data life.

B. Special Terms

The terminology 'optical digital data disk (OD^)' is gaining acceptance in the

computer storage media community in order to differentiate this computer

1
,. peripheral storage technology from optical disk technology which is used in

audio and video home entertainment systems. The term was suggested in

February 1983, by the Computer Storage Media Group of ICST.

A list of symbols, abbreviations, and acronyms used in this proceedings is in

Appendix A.

A preliminary glossary written by a task group of the X3 Information Processing

Systems Committee of the American National Standards Institute (ANSI) is in

Appendix B.

C. Participants

Current and future 0D3 users, manufacturers, and technical experts presented

papers, and participated in both panels and open discussions.

Forty-six current and potential optical disk users participated, representing

twenty-seven different Federal and commercial organizations. These users were familiar with the applications of OD^ technology, were original

equipment manufacturers (OEM), and/or represented system integration ^ companies. A list of the workshop participants is in Appendix C.

Twenty-seven OD^ developers and suppliers participated; they represented

sixteen organizations; four were consultants, one was a trade association

delegate, and four were members of organizations engaged in computer storage

media technologies other than OD^.

Since the workshc^ participants' ccHitributions included descriptions of their

professional experiences, references were necessarily made to ^ecific suppliers

and commercial products. The inclusion or omission of these companies or products in this report does not imply an endorsement or a criticism by the

National Bureau of Standards or the National Security Agency.

D. Data Collection

To compile these proceedings, notes were taken during the workshop

presentations and panel discussions. This data was then synopsized and sent to

each presentor for his/her review, additions, and deletions. After the

participant's approval, the synopses were assembled, chronologically as the

presentations and discussions occurred during the workshop, in an effort to

record the essence of the information exchanged, in the form of these

proceedings.

E. Program and Acknowledgements

The program for this Workshop on Standardization Issues for OD^ Technology

which is described within the contents of these Proceedings, was developed by a group consisting of Mark Goldberg of the National Security Agency, Michael

Deese of Storage Technology Corporation, Edward LaBudde of LaBudde

Engineering, and Jean Freedman, of the Institute for Computer Sciences and

Technology, National Bureau of Standards.

2
The workshop program was structured into three days. Presentations and panel

discussions were selected to define the characteristics of an Optical Media Unit

and the Digital Data Channel Interfaces as Related to Drive Performance (June

1, 1983). The Applications for Digital Optical Storage and Test Methods for

Determining Relative Media and Data Life were covered on June 2, 1983.

Presentations and discussions on The Pursuit of 0D3 Data Interchange

Standards concluded the program on June 3, 1983.

The successful development and organization of the workshop program stemmed

from many spirited group meetings and discussions. These resulted in a creative and interactive workshop program, that has elicited widespread

interest from both the potential users of the 0D3 technology, as well as from

the suppliers and developers of 0D3 systems and their associated media.

I wish to express gratitude for the cooperation and diligent efforts put forth by the

United States Government and industry experts on the program committee.

I also acknowledge the significant contributions made by two members of ICST to

these proceedings. Those being Mr. Sidney B. Geller's technical editing assistance

and Mrs. Candice E. Leatherman's exceptional production of this document, which

benefited from her dedication and aesthetic secretarial skills.

Jean Freedman, Chair

Workshop on Standardization Issues for OD^ Technology

3
National Bureau of Standards/National Security Agency

Workshop on Standardization Issues for Optical

Digital Data Disk (0D3) Technology

WELCOMING REMARKS

James Burrows

National Bureau of Standards (NBS)

Mr. Burrows welcomed the participants to the Workshop on Standardization Issues

for Optical Digital Data Disk (OdS) Technology and explained the role of Institute

for Computer Sciences and Technology (ICST) at the National Bureau of Standards

(NBS) in the development of computer and network standards. He noted that

NBS/ICST works directly with industry and users in determining requirements for

standards and participates in the development of national voluntary standards,

through organizations such as the American National Standards Institute (ANSI).

NBS/ICST also participates in international standards development activities which

are carried out by the International Organization for Standardization (ISO) and other

international groups.

The establishment of a national standard is a process that often takes five or more

years to complete. NBS/ICST facilitates the standards writing process by chairing

many groups and committees and by preparing technical specifications. Another

important function of NBS/ICST is the preparation of guidelines which provide

explanatory material and guidance to Federal ADP managers and others on the

management and use of computers and good ADP operating practices. NBS/ICST

also develops procedures for verifying the performance of products for conformance

to standards.

Because of the cost and time required to participate, many users are unable to be

active in the development of standards. NBS/ICST continues to serve as an advocate for the users in order to assure that their interests are not neglected.

Another obstacle to the voluntary standards process is the lack of a mechanism for

enforcing attendance at standards meetings or to compel necessary action on the

part of committee members. Because most of the participants are not able to

devote their full-time efforts to standards, NBS representatives on various standards

committees can provide the important element of continuity, since this is their

primary activity. NBS also serves as a source of information on standards activities

to the Federal government at large.

Mr. Burrows encouraged the workshop attendees to continue to participate in the

development of standards for OD^.

4
National Bureau of Standards/National Security Agency

Workshop on Standardization Issues for Optical

Digital Data Disk (0D3) Technology

OPENING REMARKS

John Riganati

National Bureau of Standards (NBS)

Dr. Riganati described the rationale and the objectives of the workshop. The

sponsors for this workshop are the National Bureau of Standards (NBS) which serves

as the focal point for Federal ADP activity, and the National Security Agency (NSA)

which is a significant user and developer of leading-edge technology.

Dr. Riganati called attention to the voluntary process by which standards are achieved through consensus. Vendors don't want the users to dictate their product

lines, while users don't want to be held captive by a single vendor. He described the

role of NBS as a laboratory-supported activity in its involvement with standards, and

indicated that NBS has a full range of laboratory facilities as well as the technical

competence which is required for the exploration and evaluation of a new

technology. These factors provide a sound basis for formulating technical judgments

upon which to base standards decisions.

One of the current interests at NBS is the characterization and assessment of the

life expectancy of media used for data and image storage. NBS has always had a strong interest in new technologies and functions as a catalyst in bringing such

technologies into productive use. It also serves as an independent arbiter in bringing

together suppliers of new equipment and techniques with potential users.

The workshop participants were carefully selected in order to achieve a balance

among product developers, users, government agencies, universities, and system

integrators. Fifty-five percent of the participants are in the user category.

Dr. Riganati encouraged the participants to give personal opinions when addressing

technical issues, and to represent their business interests on matters of consensus.

Dr. Riganati announced that the workshop would be concerned with exploring the

characteristics of a new system element, the OD^. Some products are beginning to

reach the market, while others are undergoing initial user evaluation. He sensed

that the interest in OD^ is now increasing rapidly, thus emphasizing the importance

of a timely initiation of standards activities. He urged the participants to direct

their attention to the media interchange issues.

Dr. Riganati also noted that there are various ways in which a market can develop.

The first supplier to reach the market can create demand and establish a user community. However, as successive suppliers emerge, the market may become

stratified; i.e., each vendor will develop its own constituency. The goal of NBS is to see a compatible market capable of media interchange, rather than a stratified one.

The timing of OD^ standardization is considered to be too soon by some and by

others, too late. One of the reasons for having this workshop is to ascertain how the

participants view the timing of OD^ standardization and also to provide an

information source for planning future NBS standards activity.

5
National Bureau of Standards/National Security Agency

Workshop on Standardization Issues for Optical

Digital Data Disk (0D3) Technology

INTRODUCTION TO THE WORKSHOP PRESENTATIONS AND DISCUSSIONS

Jean Freedman

National Bureau of Standards (NBS)

and

Mark Goldberg

National Security ^ency (NSA)

Jean Freedman, who both chaired the Workshop on Standardization Issues for GD^

Technology and was also a member of the program committee, introduced the other

members of the committee, namely, Mark Goldberg of the National Security

Agency, Mike Deese of Storage Technology Corporation, and Edward LaBudde of

LaBudde Engineering Corporation. Jean then reviewed the three-day workshop

schedule. (She had explicitly reviewed it with each participant, weeks prior to the

actual occurrence of the workshop, allowing the participants time to prepare.)

Jean caUed the participants' attention to the three days covered by the workshop

program. As specified in the program (which is comprehensively covered in the

Workshop Proceedings Table of Contents), the first day's presentations and

discussions are devoted primarily to defining the characteristics of 0d3 media and

system interfaces, and their relationships to the drive performance. The second day

is dedicated to discussion of 0D3 applications and media testing and the third (final)

day of the workshop covers the prospects and pursuit of OD^ data interchange

standards.

Mark Goldberg of NSA cautioned as to the difficulty of arriving at a standard, and

noted that even a modest system change could have a ripple effect throughout an

0D'> system. He advised that the workshop participants consider whether any 0D3

media or system parameters could be standardized, and if so, what parameters?

6
1. DAY 1: WEDNESDAY, JUNE 1, 1983 - CHARACTERISTICS

OF AN OPTICAL MEDIA UNIT AND THE DIGITAL DATA

CHANNEL INTERFACES AS RELATED TO DRIVE PERFORMANCE

1.1 SESSION I PRESENTATIONS AND DISCUSSIONS - UNRECORDED OPTICAL MEDIA UNIT CHARACTERISTICS

1.1.1 THE CARTRIDGE AND DESK INTERFACES

Physical, Labelling, and Handling

By Boris Muchnik

Storage Technology Corporation (STC)

Key words: cartridge; disk dust protection; environmental factors; media

protection; standardization.

Introduction

Mr. Muchnik showed an STC cartridge containing an optical disk on a slide-out tray.

In operation, the disk would be lifted from the tray (which is within the disk drive)

and the disk would be spun outside the cartridge (see fig. 1). He suggested a variety

of factors that might be considered for standardization, discussed as follows.

Cartridge Requirements

The cartridge provides the media protection from contamination and abuse during

handling and storage. Tradeoffs, which affect cost and function, should be

considered in deciding to design a disk which can or cannot be removed from its

cartridge. Since the environment in the drive is considered semi-clean, protection

provided by the cartridge is less important once the cartridge is loaded. For

example, if the disk remains in the cartridge, there must be a reading window. This

requirement adds complexity to the cartridge design, and the window would also

require cleaning. Spinning of the disk within the cartridge also risks contamination

stemming from the cartridge.

The cartridge design must incorporate protection from environmental factors such

as temperature, humidity, and altitude, vibration, and non-operational shock.

Prerequisite to a meaningful standards effort is the need for definitions, including

such items as the disk-unit dimensions, thicknesses, axial position of the disk

surface, and axial movement.

Mr. Muchnik suggested the following OD^ cartridge characteristics may be

considered for standardization:

(1) Physical size and weight

(2) Keying

(3) Restraint of disk in cartridge

(4) Machine/human readable ID

(5) Disk support structure for disk within drive

7
(6) Disk removal in drive

(7) Features for tamper-proofing

(8) Over-limit temperature indication

(9) Machine-handling features

(10) File protection, write inhibit

(11) Features for sensing that the cartridge is present, mounted, and ready

Discussion

Mr. Muchnik noted that the 0D3 cartridge was primarily designed for disk dust

protection in particle sizes ranging from 25 to 200 /xm (1000 to 8000 /tin), since the

thickness of the disk overcoat was sufficient to cause defocusing of dust smaller

than 25 yum (1000 fxin). (Particles of this size would not be detected.)

He noted that studies are underway to ascertain the air quality in different

locations, to provide guidance for environmental testing. He noted that there was

some dust filtration in the drive, but that dust protection is ultimately the result of

several factors in the disk/cartridge configuration.

Cartridge Shell

Figure 1. Cartridge Assembly

(Muchnik - Storage Technology Corporation)

8
1.1.2 PHYSICAL AND MECHANICAL CHARACTERISTICS OF AN

UNRECORDED OPTICAL MEDIA UNIT: SPECIFIABLE

PARAMETERS REQUIRED FOR DATA INTERCHANGE

By Philip Sctieinert

Burroughs Corporation

Key words: dimensions; disk zones; geometry; mechanical properties; physical

interface; surface characteristics.

Introduction

Mr. Scheinert concentrated his presentation on the specifiable parameters required

for data interchange. He proposed that standards should deal with the minimum set

of physical and mechanical characteristics required to allow data interchange for

Optical Media Units (OMU). He loosely grouped these characteristics into the

following four categories:

(1) Optical Digital Data Disk Geometry

(2) Optical Digital Data Disk Dimensions

(3) Optical Digital Data Disk Mechanical Properties

(4) Optical Digital Data Disk Surface Characteristics

(1) Optical Digital Data Disk Geometry

Standard Required Because

Specification Definition/Description of Direct Interaction with;

Recording Zone Region of the OMU which may Translator

be accessed and written on and

read by an optical memory

drive unit. Within this zone,

all recording (information)

layer performance specifications

must be met.

Handling Zone

Clamping Zone

Region of the OMU which may

be physically contacted by a mechanical handling mechanism.

Region of the OMU which will

be in contact with the drive

unit spindle and clamping

mechanism.

Handling Mechanism/

Cartridge

Spindle/Clamping

Mechanism

Edge Geometry of the outer and/or

inner edge of the OMU

pertaining to handling and/or

clamping.

Handling and/or Clamping

Mechanism

Physical Location

of OMU Surfaces

Regions to which the OMU

surfaces are restricted.

Objective, Cartridge

9
Mr. Scheinert introduced a figure to illustrate various disk zones (see fig. 1). These

include: a small handling zone at the periphery of the disk, a clamping zone around

the spindle hole, and a recording zone occupying the annular space between these

two.

He introduced a figure designating regions lying adjacent to the faces of the disk

showing the domain of the disk and protective coating (see f^. 2).

Specification

Outside Diameter

(2) Optical Digital Data Disk Dimensions

Definition/Description

Defines greatest dimension

of OMU

Standard Required Because

of Direct Interaction with;

Cartridge/Handling

Mechanism

Inside Diameter Defines hole size Spindle/Clamping

Mechanism

Noncircularity of

the Outside

Diameter

Noncircularity of

the Inside

Diameter

Noncircularity may be defined

as the deviation from a perfect circle whose center

is the mechanical center of

the OMU. The mechanical

center of the OMU is the

center of the mathematical

circle which is the least

squares fit to the OMU

contour.

Cartridge/Handling

Mechanism

Concentricity Difference in the mechanical

center locations of the

inner and outer diameters of

the OMU

Spindle, Tracking

Thickness in the

Clamping Zone

Thickness of the OMU that will

be contacted by the drive unit

disk clamp

Clamping Mechanism

10
(3) Optical Digital Data Disk Mechanical Properties

Specification

Mass

Unbalance

Definition/Description

Mass used instead of weight

for non-earth surface

environments

Product of the total mass of

the OMU and the distance

between the center of gravity

of the disk and the axis of

the disk

Standard Required Because

of Direct Interaction with;

Spindle Motor

Spindle, Tracking

Protective Layer

Hardness

Clamping Zone

Hardness

Handling Zone

Hardness

Hardness description (scale)

will be determined by specific

test method

Hardness description (scale)

will be determined by specific

test method

Hardness description (scale)

will be determined by specific

test method

Environment, Cleaning

Clamping Mechanism

Handling Mechanism

(4) Optical Digital Data Disk Surface Characteristics

Specification

Recording Surface

Axial Runout

Recording Surface

Axial Acceleration

Protective Layer

Static

Characteristics

Definition/Description

(Zmax-Zmin) for cylindrical

coordinates with 0 the

rotation direction, specifying

the rotation plane, and Z

being perpendicular to the

rotation plane

Second derivative of Z {$)

with respect to

Characteristics with respect

to static charge and decay

and dust attraction and

retention

Standard Required Because

of Direct Interaction with:

Focus Motor

Focus Motor

Objective, Cartridge and

Drive Environment

He noted that the disk surface should not be "sticky," either due to electrostatic

attraction or to being hygroscopic.

11
Discussion

Mr. Scheinert indicated that his presentation referred primarily to single-sided

disks, but could be extended to double -sided. He did not address the cartridge issue as such, but said that some form of protection was assumed. The suggestion was

made that the standard should provide a minimal set of values rather than an

optimal set, thereby giving vendors an opportunity to supply a range of products.

(Environmental conditions could be noted in the appendix of the standard.)

Mr. Scheinert felt that questions on friction and clamping factors should be

addressed mainly in the drive specification. Centering of the disk is performed by

fingers which apply pressure to the disk to center it on the spindle. The present

tolerances are approximately 0.05 mm (0.002 in), but he expects manufacturing to

go to 0.025 mm (0.001 in) at just a slight extra cost. He felt that the expense of a hub per disk could be avoided. It was suggested by a workshop participant that the

radius of gyration should be specified, since it affects the ability to accelerate a

disk.

With regard to a cartridge, Mr. Scheinert stated that he expected the disk to be

handled from the outside and clamped from the inside. He was asked about the

effect of entrapped air, due to the closeness of the disk surface to the cartridge.

He felt that this should be addressed in the drive/cartridge requirements.

The question of specifying the hardness of the overcoat was raised. It was argued

that an abrasion specification might be more appropriate. Mr. Scheinert then

indicated that hardness may not be the correct (or only) term to specify in the

mechanical properties of the protective layer (and the clamping and handling zones).

"Hardness" was used to indicate that mechanical properties of these regions must be

specified, because of interaction with the drive, cartridge, and environment. It was

further suggested that the specification of proper cleaning methods might be more

appropriate than an abrasion specification. Mr. Scheinert noted that static charge is a main factor in dust adhesion for particles below approximately 100 fim

(4000 /xin). The importance of avoiding moisture was stressed.

A widely-held opinion of participants was that the number of specifications should

be kept to a minimum, and that the market would shake out the inferior products. It was noted that the United Kingdom tends to view such standards as procurement

documents, whereas in the United States, a purchaser is expected to include much

more information in the procurement document. One common U.S. requirement is to include methods of testing for compliance with the specification.

The use of hubs to achieve more precise centering was further discussed. It was

noted that if the responsibility for maintaining proper centering is placed solely on

the spindle rather than using hubs, then—if the machine gets out of adjustment—aU

disks will be in trouble. Whereas, if a hub in a particular disk goes bad, only that

disk will malfunction. It was observed that a spindle will operate with many more

disks than vice versa. It was stated that hubs would be prohibitively expensive, but

this was countered by the experience with floppy disks, where the cost continues to

decrease despite the addition of hubs to the disks.

12
Before the discussion, Mr. Scheinert acknowledged that it might be appropriate to

allow a difference of a few thousandths of an inch of spacing between the recording zone and the active portion of that zone.

Figure 1. Single Sided OMU*

(Scheinert - Burroughs Corporation)

13
CNI on c •H o 4-1 •H o 03 00 U

<u -a o

pi 0)

a

1—1 o S-i c •H o c C •H cn u o o

•H •H tH <D CO

fcO tH iH

0) 03 CxO 60

IH in no c c H CO )-i •H •H

US ur .—1

^-^ e • pq rH rH CN

CO 1 4-1 4-1 a OJ

03u 4-1 •U u D u o O 5-1 oc 0) C •H c

CO •H

tH 0) rH rH J-l cu y

?^ c/o CO CO La

OJ

a

a (U fa ca AT u j-i D 0 O

0)

4-1 o o o PL,

14
1.1.3 OPTICAL CHARACTERISTICS OF A DESK/CARTRIDGE MEDIA UNIT

By Roland Malissin

Thomson-CSF

Key words: absorptance of the sensitive layer; angle of the protective component

(versus beam axis)—often referred to as tilt angle; birefringence; protective

component—often referred to as protective layer; reflectance of the sensitive

layer; self protected disk; sensitive layer; surface defects, thickness of the

protected component.

Introduction

Mr. Malissin considered the following optical characteristics of a disk/cartridge

media unit in his presentation:

(1) What cartridge, what disk?

(2) Disk/cartridge parameters producing optical effects.

(3) Effects of the geometrical parameters of the protective component.

(4) Effects of the optical parameters of the protective component.

(5) Effects of the surface of the protective component.

(6) Optical effects of the sensitive layer.

Mr. Malissin began his presentation by showing a binary decision tree, based on

several design factors, which were related to the degree of protection of the disk

(see fig. 1). These factors considered (a) whether a cartridge was used, (b) whether

the disk remained inside the cartridge during operation, (c) was there a shutter

opening in the cartridge, and (d) was the cartridge dust-proof? He visualized the

disk as having a sensitive layer protected by a protective component. The

protective component was viewed as either a window, a disk component, or the

substrate (see fig. 2).

Optical Characteristics

The optical path was illustrated, consisting of a normally convergent beam passing

through air, an air/dielectric diopter, a dielectric associated with the protection

components, and the sensitive layer (see f^. 3). The protective component should

be of uniform thickness, in which case its outer surface will be parallel with the

sensitive surface. Distortion of the spot can occur if the protective component does

not have its nominal thickness, its surface is not normal to the beam axis, the

refractive index does not have its nominal value, it exhibits birefringence, or there are surface defects at the air/dielectric diopter (see f^. 3). The sensitive layer may

show variations in reflectance and absorption, and these may be functions of

wavelength. Changes in the size and shape of the focused spot can directly affect

the readout and can result in loss of servo tracking. Impacts of the surface

sensitivities on the media response are shown in f^s. 4, 5, 6, and 7.

The effect of surface defects depends on the size of the defect image at the

sensitive surface. A speck will cast a defocused shadow, and this will have a change

in the signal level associated with it.

15
Discussion

Mr. Malissin noted that these parameters can vary over a disk, from one disk to

another, and can also change with time. It is necessary to establish a range of

allowable variations for acceptable operation and to remain within this range over

all operating conditions.

As to the thicknesses of the layers, he noted that these will be dependent on the

application. He indicated that there can be a loss of power resulting from specks of

extraneous matter, the lost power being roughly proportional to the total area of all

the specs on the surface, inside the light spot. He noted that these specks are

generally not completely opaque. When asked about mass store systems for

high-end versus low-end applications, he replied that the optical considerations may

be more critical in the high-end applications. (Applications are discussed on Day 2,

Session 1, see section 2.1.)

Figure 1. What Cartridge, Wh;

(Malissin - Thomson-CSF)

9 IS THERE A

CARTRIDGE?

NO

DUST PROOF

CARTRIDGE?

r

YES

UNPROTECTED

DISK

YES

_JL

NO

DISK REMAINS INSIDE

THE CARTRIDGE?

r

YES

I NO

OPENING

SHUTTER?

YES

1

NO

SELF-PROTECTED

DISK

A

SELF-PROTECTED

DISK

B

SELF-PROTECTEE

DISK

C

SELF-PROTECTED

DISK

D

16
\ \

OBJECTIVE LENS

PROTECTIVE COMPONENT

= CARTRIDGE WINDOW

OR DISK COMPONENT

SENSITIVE LAYER

SUBSTRATE

OBJECTIVE LENS

\ PROTECTIVE COMPONENT

= SUBSTRATE

SENSITIVE LAYER

OBJECTIVE LENS

wwwwxww

PROTECTIVE COMPONENT

SENSITIVE LAYER

SUBSTRATE

Figure 2, Protective Element Some Possible Cases

(Malissin — Thomson-CSF)

17
BEAM AXIS

AIR/DIELECTRIC

DIOPTER

FOCUS PLANE

SENSITIVE LAYER

DIELECTRIC (REFRACTIVE INDEX N)

The parallel plate on the path of the convergent beam produces

distortion of the focused spot if:

. It has not its nominal thickness,

. It is not normal to the axis of the beam,

. It has not its nominal refractive index,

. It exhibits birefringence,

. There are surface defects at the air/dielectric

diopter

.

The sensitive layer can show itself variation of reflectance and

absorptance

.

Figure 3. Parameters Producing Optical Effects

(Malissin - Thomson-CSF)

18
A B C

A NOMINAL CASE

B THICKNESS ERROR

C ANGLE ERROR

- The thickness error increases the focused spot diameter; the

angle error Introduces widening and asymmetry of the spot.

- Both lead to a loss of sensitivity during recording and to a loss of definition during read out.

- Both can eventually mislead the optical sensors used for

focusing and radial tracking.

Figure 4. Geometrical Parameters

(Malissin - Thomson-CSF)

19
OPTICAL PARAMETERS

- Error on the mean value of the refractive index increases the

focused spot diameter.

- Inhomogeneity of the refractive index introduces distortion

of the focused spot.

- Birefringence of the material introduces distortion of the

focused spot.

Figure 5.

(Malissin - Thomson-CSF)

20
<)) = FOCUSED SPOT DIAMETEB

d = DEFECT SIZE

D = DIAMETER OF DEFECT AS SEEN IN THE FOCUS PLANE

If D»(}>, the defect produces a small loss of power inside the

focused spot but no distortion of the spot, the lost power

being radiated into a wide area.

Conversely if D is in the range of (/» the focused spot is

distorted

.

Figure 6, Surface Defects

(Malissin - Thomson-CSF)

21
Reflectance "R" and absorptance "A" of the disk are both

essentially chaLacteristics of the sensitive layer itself.

. "A" and "R" can change or not with wavelength

. "A" and "R" can change across a disk and from one disk

to another one.

. Variations of "R" lead to changes in: data read out,

radial tracking and focusing signal level.

. Variations of "A" lead to changes in: recording

sensitivity.

Figure 7. Optical Effects of the Sensitive Layer

(Malissin - Thomson-CSF)

22
1.1.4 QUALITY CHARACTERISTICS OF AN OPTICAL

DISK RECORDING SURFACE

By Miguel Capote

Optical Coating Laboratory, Inc. (OCLI)

Key words: birefringence; blemishes; defects; dust; index of refraction; overcoats;

overcoat thickness; thickness variation.

Introduction

Mr. Capote directed his remarks primarily to the characterization of the disk

overcoat and its blemishes. He discussed the topic of media overcoat with emphasis

on such factors as overcoat constraints, dust size, and apparent flatness. He also

noted the types of observed overcoat blemishes, their impact, and an approach to

their remedy.

Mr. Capote advocates keeping specifications of OD^ quality characteristics to the

minimum. He suggested the following overcoat constraints be specified to assess

disk quality:

(1) Thickness variation

(2) Index variation

(3) Birefringence

(4) Dust particle size

Overcoat Constraints

(1) Thickness variation over entire surface: +15 nm for a numerical aperture of

.65 NA.

Variations in overcoat thickness can result in spot defocusing. The absolute

thickness constraint is the same for both thin 0.170 Atmm (0.007 uin) and thick

1.200 Mmm (0.005 Min) coatings, therefore dimensional control becomes more

stringent (percentagewise) for the thicker coatings.

(2) Index variation: (+1% batch to batch)

Index variation can vary +5% if compensated by thickness (thickness X index =

constant).

(3) Birefrii^enee: (Less than A /20)

Birefringence includes signal modulation and asymmetric optical effects.

(4) Dust Particle Size: The following overcoat and particle dimensions produce a 25% drop in peak irradiance:

23
Overcoat Thickness Particle Diameter

0.170 Mmm (0.007 jxin)

1.200 Mmm (0.005 /xin)

30 Mm (1200 Min)

225 Mm (9000 Min)

The worst case occurs when a perfectly absorbing dust particle is located at the

center of the beam. It was noted that dust impacts the transmitted power and the

peak irradiance.

Most surfaces are sensitive to the peak irradiance threshold. An occasional cleaning

of the disk is considered essential. In addition to removing dust and surface film,

there may also be accumulated corrosion products that should be removed.

Disk surface axial runout can be detected and measured by observing the variations

in focus motor current during disk rotation (see fig. 1).

Surface blemishes can be observed by viewing the photodetector output and are of

two types, positive and negative (see fig. 2). Positive blemishes are those which

produce extraneous signals where none should exist, while negative blemishes are

those which cause signal level losses or signal dropouts. Large blemishes can result

from imbedded dust (see fig. 3). The focus system servo error signal shows an

erratic excursion which may span many bits, perhaps 50 or more. Focus accuracy

may be lost in the vicinity of the blemish which can result in the loss of many bits.

The proposed approach to dealing with blemishes is to employ error -free writing in

which the software relocates the data so that the data is error-free when it is first

written. This overcomes the effect of blemishes at the cost of a slight reduction in

disk capacity rather than at the expense of the data integrity. The implication is that the blemish rate affects the disk capacity rather than the data integrity.

Mr. Capote displayed a U-shaped curve which showed that there is a minimum cost

per bit based on the trade-off between the disk yield and the disk capacity as

functions of the allowable defect rate (see f^. 4).

Mr. Capote was asked about the relative merits of disk cleaning versus data

protection through the relocation of the data during writing. He suggested that an

error rate count could be developed which indicated when the need for disk cleaning

occurred. Mr. Capote was asked if there was a trade-off between the use of more

expensive drives as compared to more expensive disks. He responded that most

hardware designs call for error relocation schemes as described. The cost of

implementing these is minimal compared with the cost of other hardware features.

It was observed that a distinction should be made between defects in the coatings

and the defects in the sensitive recording surface. Mr. Capote also noted that he

was emphasizing defects occurring during manufacture rather than those that might

occur with time in use.

Surface Blemishes

Discussion

24
Mr. Capote was asked if an air separation could diminish the effects of blemishes,

and he replied that the air space was not an appropriate solution due to the

subsequent increased manufacturing complexity.

25
OQH

<:

QO

II

HW

:sZW

Pi

H Pi: O C 1—1

;:=) <

Pi

M

CO

<:M

COw ^ w u 1 2; o 1 fa u w M 11 <

fa fa H< ot/3 O

t:^ C/3

U

M > fa Q o H >> —-

i> : ooCNl OoOOoo

00oo o 00 v£) <r

--I o o o o

NOIIVHaiaDDV 3DVJHns

in in o LoI u

fa) cw

Pi

fa o

fa]

2;c

I—I <HO

Pi

I—I Q

QOCM1 E—' W

pii

fa!

M ^ T fa w r T <i Pi

fa] P2 vO o

fa r—1

PhO

tl>

H<< to

CO

U

M o M O fa fa

fa >^ o P3

W

C 1—1

fa

Q

Pi Pi H

W

U hJ

fal < M

fa

t—

PioHi

cn

^3uo

fa

>-< PQQ

fa

Pi

1:3 <

fa

ISO

PiX< w

:^ Pi CO Pi

I—I HW

fal S<

I—I

faOH

U• oI 0)U OJ 60 O

•H C- fa m

26
27
FOCUS ERROR SIGNAL

.5v/dis, .Zms/div

READ DETECTOR

50mv/div, .2ms/div

CHARACTERISTICS

. Rare, 1-4 per disk

. Caused by imbedded dust particle

. Can be eliminated at expense of yield

. Affects focus severely

. 50 or more bits across

Figure 3. Large Blemish

(Capote - OCLI)

28
DEFECT RATE

Figure A,

(Capote - OCLI)

29
1.1.5 QUALITY CHARACTERISTICS OF DIGITAL

OPTICAL RECORDING MEDIA

By Jan Verhoeven

Optical Media Laboratories (OML)

Key words: data integrity; defect density; localized errors; media characteristics;

media specification; media test bed; quality characteristics.

Introduction

Dr. Verhoeven displayed a disk cartridge containing a 305 mm (12 in) double-sided

optical disk. The disk is a composition of two circular glass disks (substrates)

bonded to and separated by an inner and an outer spacer as shown in fig. 1.

On the inner side of the substrate a sensitive layer is deposited onto an intermediate

layer in which are embedded prerecorded grooves that carry tracking, heading

information, and in-track clock signals, as shown in figs. 2 and 3.

The beginning of each sector contains synchronization information, a sector number,

and a track number.

Characterization

Optical Media Laboratories performs testing and measurement of dimensional

specifications such as disk inbalance and excentricity; see fig. 4. Testing of quality

specifications included homogenity, flatness, sensitivity, signal-to-noise ratio,

condition of pregrooving, bit error rate (BER), modulation depth, and ageing

properties. Over a period of several years, hundreds of disks have been tested

beyond the normal production inspection by computer-control-led media test beds,

fi^. 5, and other test equipment. This media test bed enables the localization of bit errors, defects, and servo errors on a disk, see fig. 6.

This enabled the investigation of the density distribution of the defects and of the

relation between defects and bit errors, see fig. 7. The measurement of defects

presents a non-destructive quality test of a disk, which may be useful for

certification procedures.

Discussion

Dr. Verhoeven felt that individual disk certification should be performed for disks

which are intended for long-life applications. When asked if disks could be tested by

means other than scanning, he stated that they could be tested on a track-by-track

level in tens of minutes per disk by advanced equipment.

When asked about the relative merits of servo-written media versus pregrooved

media, Dr. Verhoeven stated that this was a valid subject for further consideration.

Regarding the possible influence on error rate due to pregrooving, he noted that few

errors could be attributed to this source.

30
It was suggested that there might be performance limitations with the pregroove

process since the replication procedure may contribute defects to the disk.

Dr. Verhoeven did not consider this to be the case. A question was raised as to whether print-through might occur to the apparent

closeness of the two sensitive layers in a double-sided configuration. This was

answered emphatically in the negative, since the actual spacing is an adequate

0.3 mm (0.001 in), and the hole formation is based on removing material to the edge

instead of evaporation of material.

As to the measurement of the signal-to-noise ratio, Dr. Verhoeven explained that a

test pattern was applied to the disk and that the signal and noise levels were

measured in central aperture under specified conditions with respect to frequency,

numerical aperture, rotation speed, and detection band width.

PREGROOVED SENSITIVE LAYER

Figure 1. Schematic View of the Sandwich Structure

of a TF-Based DOR Disk

(Verhoeven - Optical Media Laboratories)

31
PRERECORDED

HEADING

DISK

ROTATION

Figure 2. Schematic Showing the Sectorized

Pregrooves of a Disk

(Verhoeven - Optical Media Laboratories)

32
oooo - oo-ooO O-O-O—

oooo—

1 u -n 1 5 v? V 1 ri 0 E 4 2 2 0 4 / 9

SEM photograph of the pregrooves with in-track clock with written

holes

.

The holes shown have a diameter of about 0.9uTn. The tracks are 1.6um apart.

Figure 3.

(Verhoeven - Optical Media Laboratories)

33
DIMENSIONS - INNER AND OUTER DIAMETER

- SUBSTRATE THICKNESS

.:

• - - SANDWICH THICKNESS

. - UNBALANCE

SIGNAL CHARACTERISTICS - SIGNAL TO NOISE RATIO

- MODULATION DEPTHS

- PREGROOVE SIGNAL

- DATA SIGNAL CHARACTERISTICS

- HEADER RECOGNITION

- CLOCK REGENERATION

SERVO ASPECTS

DATA INTEGRITY

HOLE FORMATION

AGEING PROPERTIES

FLATNESS

ECCENTRICITY

ACCELERATION

BIT ERROR RATE

DROPOUTS

DEFECT DENSITY

DEFECT DISTRIBUTION

SENSITIVITY

HOMOGENEITY

MATERIAL COMPOSITION

LAYER THICKNESS

ACCELERATED

LEAKAGE

SHELF LIFE

CERTIFICATION - TRACKING

- SEGMENT HEADERS

- READABILITY

- FLAGGING OF DEFECTS

Figure 4. Summary of Media Characteristics

and Media Qualifications

(Verhoeven - Optical Media Laboratories)

34
write

DATA

original

DATA

life test

read

ISK

RECORDER

COMPARE

FILE

DATA

ERRORS

SERVO

ERRORS

RADIUS

& ANGLE

ANALVS IS

system + disk

technology

Figure 5. Blockdiagram of a Computerized Media Tescbed

(Verhoeven - Optical Media Laboratories)

35
oa o

a: o

I- o

CO o

<r o

a: lo

Iw

CO

I-O

OH

I-

^0?

ro o

I-o

UJ

0) c

4-1 0) PQ

<; co

0)m

x; •

CNl >—1

0) c t3 •H •H >-l 0) )-l <D X) o

4-1 •u

W E TO •H 3 CU >-( Q H O

Xi

CT3 TO TO CJ •H hJ C 13 o OJ TO X •HT3

4-1 01 0) C

<u CC 4-1

14-1 .H

0)O TO o O o •H • 4-1 o r-l 0) i-H V-i o c D o m

•H (U TO

4-1 0) c

n3 ED >

•H

t—1

TOO

CC AS J= o a o COu > H ^—

(Uu

bO

36
PQ

CO

Q) •HUo

COUO

,Q

CO

0)

(1) X. u3 rH

60 CO •H uoc>o>

37
1.1.6 OPTICAL DIGITAL DATA DISK

Media Aims and Potential Standardization

By Noel Proudfoot

Eastman Kodak Company

Key words: definitions; media aims; parameters; quality assurance program,

standardization.

Introduction

The need for definition of terms and a common understanding of highly technical

information is necessary in an emerging technology. This is true for media

manufacturers involved in performance specifications or testing of optical disks; for

the disk drive manufacturers; and for the users of both drives and media. The

purpose of this paper is to put forward a plan for media aims and how these were

developed; some definitions and understanding of the parameters selected; and

suggested parameters that are appropriate for standardization.

Media Aims

During the research and development effort on a new product much time is spent on

getting the proper product characteristics. Some days the product requirements and

the technical hurdles needed seem to be insurmountable. As the product proceeds

toward reality, quality assurance plans must be made so that the required quality is achieved, unit after unit. Such a quality assurance program for Optical Digital Data

Disks could have the following requirements:

(1) Assure optical disks meet or exceed specifications at minimum cost

(2) Document and maintain the specifications

(3) Maintain records for optical disk traceability

(4) Establish product audits

(5) Establish information systems to assess customer reaction

(6) Provide management reports of quality level

(7) Provide adequate training of work force

Under the item "Document and maintain the specifications" could be a relatively

formal document outlining the customer's requirement for media sensitivity and bit error rate, two very important product parameters. The remaining discussion is limited to only part of this portion of the quality assurance program.

The data on curves and tables which follow are presented for example and discussion

and may not be representative of any product or proposed product.

Typically, characteristic curves of power (P) in milliwatts on the disk versus carrier

signal, noise level, and carrier-to-noise-ratio (CNR) could be generated for a

specific recording and reading geometry. For purposes of this explanation only curves of carrier and noise will be used.

38
The first item needed is information that represents the ideal characteristics for

customers within the capabilities of the product being developed. This could be

called the customer reference. The customer reference can represent data from

specially made test equipment or commercially available write-read equipment.

Such data are shown in fig. 1 including appropriate other necessary test

information(l).

Data are also needed which represent the characteristics, at the time of

manufacture in order to monitor production. This could be called the manufacturing

aim. It should be based on a significant number of real production lots and the

manufacturing aim could be representative of the means of those lots which meet

product specifications. Tests are usually made on specially made write-read

equipment (fig. 2).

There is also a need to collect comparative data on the product at the average age

from manufacture when customers start writing and reading the disks. This average

age from manufacture could be 1 month, 3 months, 6 months, or 1 year depending on

distribution systems and other arrangements. This information will indicate the

expected characteristics of the disk at that time if tested on the specially made test

equipment. It should include sensitivity and track changes with time, if any. This

could be called the customer aim if based on manufacturing aim level product plus

keeping factors (fig. 3).

One additional set of curves and data are needed to complete the package. This is a customer aim specified in terms of the customer write-read equipment (fig. 4). The

customer write-read equipment could be identical to the specially made test

write-read equipment but almost never is. The repeatability characteristics for the

test equipment generally needs to be significantly better than customer equipment

to assure appropriate media quality level for customers.

A comparison of the customer aim curves and the customer reference curves can

readily show what more might be achieved in a product system.

Tabulated parameters are a convenient way to trace the manufacturing aim through

keeping to the customer aim - customer reference (table 1). Some definitions are

included for understanding.

The aims will change and need to be updated as manufacturing methods change,

distribution systems change, etc. The customer reference will not likely change

unless the test equipment changes.

There is much more that needs attention to assure good product to customers. Some

of these are keeping properties over more time, higher temperatures, etc. The

overall program includes many other items. This is a plan for setting up a rather

formal, documented set of critical parameters so that there can be management and

organization agreement on product quality as manufactured fresh and when used by

the customer.

39
Definitions

Before standards can be written on media sensitivity or bit error rate, terms need to

be agreed to which define the appropriate parameters. In f^. 1 are shown Carrier,

Noise, CNR, Noise Floor, 6 mw Carrier, Bit Error Rate, and curves of Carrier versus Laser Power and Noise versus Laser Power. Why were these selected; what are the

definitions; and what about the curves and listed test conditions?

The Carrier is the root-mean-square value of the Carrier amplitude (table 1

definitions). This is reported in decibels relative to a 1 millivolt reference and the

measurement can be made conveniently using a spectrum analyzer. Noise is also

measured in the same way in the presence of the corresponding Carrier level. The

Noise Floor is measured similarly except without any carrier signal present.

The Laser Output Power is available power on the disk and is plotted on a

logarithmic scale which makes for convenience in comparing curves of different

media. Ideally, the power versus carrier curve should look like that in fig. 5, where

there is no sensitivity below a certain power threshold and very high and unchanging

signal above that threshold. This ideal situation would mean that the write laser

could be used for reading with reduced power without concern for causing changes in

the written marks. Noise level should be unchanging and low over the whole range

of power.

The listed carrier and noise parameters were measured at a power level which

places the carrier signal on the high, flat portion of the curve (fig. 1). This will

yield the maximum CNR value and the flat response here provides "ruggedness" to

laser power variations. The 6 mw Carrier value is a measure of the sensitivity of

the media and this can be used on a closely controlled product. A more universal

media sensitivity measurement could be defined as the power needed to achieve a

signal level 10 dBm below carrier maximum.

The test conditions and test equipment need to be specified in order to be able to

compare useful data from different sources. Some of the needed information is listed in fig. 1 for recording and reading. This is a start on a specification where the

intent is to get the same results on the same media with test equipment made by

two manufacturers.

The definition of bit error is necessary in order to communicate satisfactorily on the

subject of bit error rate for media. One proposed definition is:

Bit Error - A single transition signal read from a written track which is displaced by more than 50 percent of the code bit synchronizer window width

from its correct location, when such displacement is due to non-functional

areas in the recording layer.

Now, if you agree on this definition, then bit error rate is easier.

Bit Error Rate - The ratio of bit errors detected upon read-out of

pseudo-random data to the total number of bits measured in the form Y x 10"^.

These definitions are for "raw" bit errors for media.

40
standardization

The need for definitions of terms and parameters for optical disks is readily

apparent. A most important and difficult project in standardization is to achieve

agreement on the definition of a wide range of technical terms in this growing

technology. Otherwise, media and disk drive manufacturers, and users of both will

become confused because of the lack of uniform definition. For instance, CNR

numbers are published in technical reports without defining carrier or noise. Yet

using "peak-to-peak" carrier signal instead of rms carrier compared to rms noise

results in a 9 dB higher CNR number for the same carrier signal. Work has begun to

define technical terms for optical disks in the American National Standards

Institute, Optical Digital Data Disk Study Group.

I would like to propose three parameters for inclusion in a standard.

(1) CNR - The definition is shown in table 1. Values for CNR are routinely

reported in the technical literature. G. J. Ammon et al. (2) have reported

CNR values in excess of 70 dB measured in a 30 KHz slot. K. Yamada

et al.^"^) reported a maximum CNR value of 69 dB. R. P. Freese et al.^^)

reported a maximum CNR of 68 dB measured in a 30 KHz bandwidth.

(2) Threshold Sensitivity - Power in mw, 10 dBm below the carrier maximum

for a specified radius (mm) and a specified rotational speed (rpm).

(3) Bit Error Rate (uncorrected) - The definition is shown in table 1. Values

for BER are also routinely reported in the technical literature. D. Y.

Lou(5) reported 5.7 x 10~^ bit error rate for a Miller modulated signal

recorded at 1.8 nm per bit. G. J. Ammon et al.(2) reported raw BER of

3 X 10-5.

There is need only for a lower limit for CNR. Threshold sensitivity needs a high

power limit if semiconductor lasers are to be used for writing; a low power limit is also needed for those systems using the same laser for write and read. The bit error rate needs to be as low as possible consistent with the tradeoffs in media

manufacturing cost, drive manufacturing cost, error detection and correction costs,

and the users' application.

Conclusion

The standardization of optical disk media measurement information is important to

the continued progress of the commercial application of optical disks and optical

disk drives. Definition of the technical terms in this emerging technology is the

first need. This would be a great help in communicating among the media suppliers,

drive manufacturers, and customers for both.

41
References

1. Kurtz, C. N. "An Optical Sealed Disk Assembly," Topical meeting on Optical

Data Storage, Optical Society of America, Lake Tahoe, NV, January 17-20,

1983.

2. Ammon, G. J.; Kenville, R. F.; Litwak, A. A.; Nigro, M. S.; and Reno, C. W.

"Performance Measurements from Digital Optical Disk Systems," SPIE Vol. 329,

Optical Disk Technology (1982), pp. 33-39.

3. Yamada, Koichi; Wantanabe, Isao; Ito, Osamu; Kubo, Takahiro. "Evaluation of

Optical Disk Surfaces," SPIE Vol, 329, Optical Disk Technology (1982), pp.

242-243.

4. Freese, R. P.; Willson, R. F.; Wald, L. D.; Robbins, W. B.; and Smith T. L.

"Characteristics of Bubble-Forming Optical Direct-Read-After-Write (DRAW)

Media," SPIE Vol. 329, Optical Disk Technology (1982), pp. 174-180.

5. Lou, David Y. "Characteristics of Optical Disks," Applied Optics, Vol. 21, No.

9, 1 May 1982, pp. 1602-1609.

Discussion

A workshop participant challenged Mr. Proudfoot's use of the carrier-to-noise ratio

measurements as opposed to signal and noise level measurements. Mr. Proudfoot

noted that carrier-to-noise ratio was an established measure for which measuring

equipment was available; it could be extended by performing the measurement at

several carrier levels. The audience commented that the bit error rate does not

have a simple relationship to carrier-to-noise ratio, and hence the latter is not

directly useful to the systems engineer. It was noted that the equipment for

measuring carrier-to-noise ratio was designed with a different application in mind

and used a 30 kHz bandwidth. When used with optical disks, it does not give useful

information about the frequency distribution of noise components. The systems

engineer needs to know about the noise behavior over the entire relevant bandwidth.

This session concluded with a brief floor discussion relative to disks which are enclosed in a cartridge versus removable disks. Martin Levene, of RCA, noted that an unconfined rotating disk acts as a pump and that the aerodynamic drag could be

reduced by keeping the disk in confinement. He further suggested that removal and

insertion of the disk could create an increased opportunity for admitting dust into

the cartridge.

(Although not stated as part of this session's discussion, an even more compelling

argument for the enclosed disk is that, in an automated access multidisk system

where disk access time is desired to be as short as possible, operation of the disk

within its cartridge is a significant time saver. Experience with the RCA

developmental jukebox systems has shown "worst case" disk access times as short as

5 to 6 seconds. If additional time were taken to remove the disk from the cartridge,

then that extra time would adversely affect disk access time.)

42
These arguments favor keeping the disk within the cartridge. This was countered

by the observation that an unconfined 356 mm (14 in) disk requires only about 8

watts to rotate it at speeds up to 1800 revolutions per minute, and that there is only a 2 to 1 ratio in the drive power which is required for a confined versus an unconfined disk. (Note that the same unconfined disk would require 57 watts at

3600 rpm.)

It was noted that if an enclosed disk has too low an air flow, eddies and pockets will

form allowing dust to accumulate, while too fast a flow will create turbulence.

These factors result in more stringent design constraints on confined disks.

It was then conjectured that there may be a need for standards for read/write

processes both inside and outside of a cartridge.

43
Table 1 (Proudfoot - Eastman Kodak Company)

MANUFACTURING AIM

dBm dBm Bit

Noise dBm dB dBm 6 mw Error

Floor Noise CNR Carrier Carrier Rate

-78 -78 70 -8 -25 Y x 10~^

CUSTOMER AIM KEEPING FACTORS

' dBm dBm Bit

Noise dBm dB dBm 6 mw Error

Floor Noise CNR Carrier Carrier Rate

Mfg. Aim 1 -78 -78 70 -8 -25 Y x lO"^

1 yr. 26°C/50% RH +3+3-3 0 0 0

Track Change NA 0 0 0 NA 0

(Six months

26°C/50% RH)

Customer Aim . -75 -75 67 -8 -25 Y x 10~^

(Test equipment)

Test equipment to 0 0-3 -3 -3 0

customer W/R

equipment

Customer Aim -75 -75 64 -11 -28 Y x lO"^

(customer W/R

equipment)

Customer Reference

75 -75 6A -11 -28 Y x 10

^

dBm - decibels referenced to one millivolt.

Noise Floor - measure 1 MHz above the carrier signal with no writing on

disk.

Noise - measured 1 MHz above the carrier signal in a fully formed track

at R = 100 mm at 1800 rpm at about 8.6 MHz carrier.

Carrier - The RMS carrier level in dBm in a 30 KHz bandwidth centered at

the fundamental (carrier frequency) of a monotone recording.

The input is a 50% duty cycle square waveform.

44
Table 1, continued

(Proudfoot - Eastman Kodak Company)

Carrier-to-Noise Ratio (CNR) - The ratio of the Carrier to the CNR Noise

level in dB.

6 mw Carrier - The carrier signal level for the 6 mw track (about

8.6 MHz).

Bit Error Rate - The ratio of errors detected upon readout of a pseudo-random data to the total number of bits

measured in the form Y x 10"^.

45
TEST CONDITIONS ;

Recording: Laser at 830 nm, 1800 rpm, R = 100 mm

Elliptical spot in track 1.0 x 1.13 ixm Fl^JHM

Reading: Laser at 633 nm Circular spot 0.72 )um FWHM

Split detector HP Spectrum Analyzer //3585A

Parameters Aim

Carrier -8 dBm

Noise -75 dBm

CNR 67 dB

Noise Floor -75 dBm

6 mW Carrier -25 dBm

Bit Error Rate y X 10-z

4 6 8 IQ

Laser output power (mH)

Figure 1. Customer Reference for a "Standard Optical Digital Data Disk"

(Proudfoot - Eastman Kodak Company)

12 14 16 1620

FOR EXAMPLE ONLY

46
TEST CONDITIONS:

Sample Preparation:

Recording: Laser at 830 nm, 1800 rpm, R = 100 mm

Elliptical spot in track 1.0 x 1.13 /xm Fl'JHM

Reading: Laser at 633 nm; Circular spot 0.72 um F\fflM

Split detector HP Spectrum Analyzer #3585A

Parameters

Carrier

Noise

CNR

Noise Floor

6 mW Carrier

Bit Error Rate

Aim Conformance Limits

-8 dBm -7 to -11 dBm

-78 dBm -76 to -80 dBm

70 dB 66 to 72 dB

-78 dBm -76 to -80 dBm

-25 dBm -22 to -30 dBm

Y X 10-z Y X 10-z

4 6 e 10 12 14 16 1620

Laser output power (mW) p^j^ example only

Figure 2. Manufacturing Aim for a "Standard"

Optical Digital Data Disk

(Proudfoot - Eastman Kodak Company)

47
TEST CONDITIONS:

Recording: Laser at 830 nm, 1800 rpm, R = 100 nun Elliptical spot in track 1.0 x 1.13 FWYQi

Reading: Laser at 633 nm Circular spot 0.72 jum FI^THM Split detector HP Spectrum Analyzer #3585A

Parameters

Carrier

Noise

CNR

Noise Floor

6 nW Carrier

Bit Error Rate

Aim

-8 dBm

-75 dBm

67 dB

-75 dBm

-25 dBm

y X 10-z

4 6 8 IQ 12 14 16 1620

Laser output poy^er (mM)

FOR EXAMPLE ONLY

Figura 3. Customer Aim for a "Standard"

Optical Digital Data Disk

(Proudfoot - Eastman Kodak Company)

48
TEST CONDITIONS:

Recording: Laser at 830 nm, 1800 rpm, R = 100 trm

Reading

:

Laser at 633 nm

Split Detector HP Spectrum Analyzer //3585A

Parameters

Aim

Carrier -11 dBm

Noise -75 dBm

CNR 6A dB

Noise Floor -75 dBm

6 mW Carrier -28 dBm

Bit Error Rate y X 10

-z

4 6 8 10 12 14 16 1820

Laser output pouter (mN)

EXAMPLE ONLY

Figure 4. Customer Aim for a "Standard"

Optical Digital Data Disk

Tested on Customer Equipment

(Proudfoot - Eastman Kodak Company)

49

II
TEST CONDITIONS:

Recording: Laser at 830 nm, 1800 rpm, R = 100 iran Elliptical spot in track 1.0 x 1.13 /um FWHM

Reading: Laser at 633 nm Circular spot 0.72 /im FWHM

Split detector HP Spectrum Analyzer //3585A

Parameters

Carrier

Noise

CNR

Noise Floor

Aim

-8 dBm

-75 dBm

67 dB

-75 dBm

I)«

o>

to

-10

-20

-30

-4 0

-50

-80

-70

-80

-90

—•4

•C^rfi^r'

4 6 8 10 12 14 16 1820

Laser output power (mW) EXAMPLE ONLY

Figure 5. Ideal Sensitivity - Optical Digital Data Disk

(Proudfoot - Eastman Kodak Company)

50
1.2 SESSION II PRESENTATIONS AND DISCUSSION - RECORDED OPTICAL MEDIA UNIT CHARACTERISTICS

1.2.1 EFFECT OF DISK MECHANICAL RUNOUT

ON DATA INTEGRITY

By Edward LaBudde

LaBudde Engineering Corporation

Key words: axial runout; focus error; hard error rate; mechanical runout; noise;

radial runout; soft error rate; tracking error.

Introduction

Mr. LaBudde offered the following definitions:

(1) Error Rate Definition:

(a) Initial defect density - Defects on unrecorded disk (non-destructive

read).

(b) Read error rate (soft) - Read bit error rate which can be cleared on

reread.

(c) Read error rate (hard) - Read bit error rate which is not clearable on

reread (this could arise from initial defect).

(2) The soft bit error rate (BER) depends on:

(a) Signal characteristics which are a function of

. Beam size (also a function of focus errors)

. Pit size

. Track error

(3) Noise characteristics depend on:

(a) Pit noise

(b) Read channel noise

(c) Mechanical noise

(d) Cotrack interference

Effects of Runout

Mr. LaBudde noted that mechanical runout can affect both the hard and soft error

rates, which are reclearable on reread for small errors and not readable for large

errors. There are two sources that cause mechanical runout: axial runout, which

causes focus error, and radial runout, which causes tracking error.

Axial runout has the effect of increasing the focus error, which is also a function of

the disturbance spectrum and the servo performance. Focus error causes an

increase in spot size, a decrease in signal amplitude, an increase in pit edge noise^

and an increase in cotrack interference. The error is expressed as follows:

51
ERROR = Disturbance Spectrum

1 + GH (servo bandwidth)

GH = Loop Gain

Radial runout produces an increase in track error, which is also a function of the

disturbance spectrum and the servo performance. Track error causes a decrease in

signal amplitude, a decrease in pit edge noise, and an increase in cotrack

interference. (See the preceding error formula.)

The mechanical runout spectrum is usually limited to low frequencies. If the runout

is large, it may blank out considerable spans (large portions) of the track. The

effects may be repeatable on reread, requiring an offset on retry.

Summary

In summary, a small mechanical runout will be within the error budget and will

produce no system errors. A medium runout may degrade the soft error rate, but

data may be recovered by retrying with offsets. A large runout can cause gross

deterioration of the read error rate, and may not be correctable.

52
1.2.2 OPTICAL CHARACTERISTICS OF RECORDED MEDIA

By Leonard Laub

Vision Three, Inc.

Key words: information surface; locally written media; mass-replicated media;

modulation; protective coating thickness; recording surface; resolution; wavelength

specificity.

Mr. Laub reviewed the process by which optical disk media modulate light in terms

of the optical path to the recording surface and the contrast offered by marks on

the information surface. There may be a wavelength specificity. Slides of various

recorded surfaces were shown. The types of modulation were characterized as deterministic redirection, absorption, scattering (non-deterministic), and

polarization rotation. Mr. Laub noted that the optical reading process is not

necessarily dependent on how the spots are formed.

Surface protection is needed against dust and scratches; however, such a protective

coating can introduce aberrations in the optical path.

Requirements exist for compatibility between mass-replicated media and locally

written media. These requirements should include reading in the absorption mode,

the protective coating thickness must correspond to the set value, the reading

wavelength and power should correspond, and the density should be limited to that

achievable by the method having lesser resolution.

53
1.2.3 ELECTRICAL CHARACTERISTICS OF THE DISK

Data and Servo Control

By Yoshito Tsunoda

Hitachi Ltd.

Key words: aberration of optics; noise characteristics; real time monitoring;

recording layer; servo control; signal characteristics; subbing layer; tracking signal.

Introduction

Mr. Tsunoda described a 305 mm (12 in) disk, two sided, with 2.6 gigabytes (2.6 x 10^

bytes) total storage capacity. The track spacing was 1.6 nm (64 Atin), with 64

sectors per track. It was pregrooved, with preformed header information. The spot

size was 1.2 Mm (30.5 Atin) to 1.6 nm (64 /xin). A tellurium -selenium formulation

was used which was found to be superior to tellurium alloy used alone. The pits

formed in this surface were very clean and uniform.

Electrical Characteristics

An evaluation of the electrical characteristics of the data should include both the

writing characteristics and the signal and noise of the reading characteristics. A

technique is available for monitoring the recorded signal during writing. Numerous

slides of waveforms were displayed, showing signals during reading and writing.

Mr. Tsunoda indicated that the noise encountered during reading was influenced by

both the recording layer and by the subbing layer (substrate). He described the

reading characteristics of the signal as being influenced by the pit pitch, pit size,

track runout offset, focus offset, and aberration of the optics.

The electrical characteristics of the servo control system should also be considered.

This system consists of a tracking servo and a focusing servo.

Mr. Tsunoda described disk writing characteristics as determined by the following

factors:

(1) Writing power versus signal level

(2) Writing power versus pit size

(3) Real time monitoring.

He suggested the following variables and associated tests be standardized:

(1) Media recording surface sensitivity:

(a) measuring method (device, pulse)

(b) specifications

54
(2) Signal characteristics:

(a) signal type (bright or dark)

(b) measuring method (device, etc.)

(c) specifications

(3) Noise characteristics:

(a) measuring method

(b) specifications

(4) Servo control signal characteristics:

(a) TR signal (groove, etc.)

55
1.2.4 DATA FORMAT, INITIALIZATION,

AND ERROR MANAGEMENT

By Di Chen

Optical Peripherals Laboratory (OPL)

Key words: data format; direct read after write (DRAW); error correction; error correction code (ECC); error detection and correction (EDAC); modulation scheme.

Introduction

Dr. Chen described an optical storage system consisting of optical digital data disk

and optical disk drive subsystems. He then described 0D3 data formatting

techniques:

(1) 0D3 Format

(a) labelling: Human Read/Machine Read (HRMR)

(b) addressing: sector and track mark

(c) tracking: tracking servo signal

(d) focusing: focusing servo signal

(e) clock: timing window for read/write

(2) Data

(a) modulation scheme: considers the laser duty cycle, user data

capability, and encoder/decoder electronics by which the data is interchanged with the user

(b) error detection and correction (EDAC): to improve BER

(c) post field: for data correction/update within a sector

(d) vector field: for pointing to correctly written sector

(e) write verify: uses Direct Read After Write (DRAW)

(f) write protect flag: flag to prevent overwrite

(3) Formatting Techniques: Formatting techniques for preformed material

consist of stamping replication or bit-by-bit formatting (servo writing); the

latter takes longer.

(a) Stamping Replication:

. Format information is embossed in depth from disk surface.

Reading of format information is by optical interference.

. Dr. Chen illustrated a typical replication process, in which a master

is formed, called a "father," from which a "mother" is formed, and

which in turn is used to form a "son" which becomes the stamper

(see f^, 1). Layers of plating are used to obtained a meteilized

surface.

56
(b) Bit-by-Bit Formatting:

. Format information is written on an unrecorded disk bit-by-bit.

Reading of format information is the same as reading written data

bits.

Recording Geometries

The two basic recording geometries are the spiral and concentric track

configuration. The spiral track geometry is widely used for entertainment material

where continuously moving displays are desired, although the spiral track has also

been adapted for use in digital data storage. The concentric track geometry

corresponds closely to conventional track layouts on magnetic disks. In either case,

the reading method must be capable of jumping by one groove at the end of a track.

That is, if the data are to be reread repetitively from a spiral groove, it is necessary to jump back at the end of the groove to the start of the same groove. If data are to be read sequentially from concentric grooves, it becomes necessary to

jump to the next groove at the end of the current groove. It is immaterial to the

track servo as to whether it is following a spiral groove or a concentric groove,

because the track spacing is so small compared to the possible radial runout of the

disk that the servo is designed to accommodate.

There are two versions of track servo techniques. One uses a single spot which is kept centered over the pregrooved track in push-pull fashion. The other uses two

spots, one following each edge of the track (see fig. 2).

A. Review of Recording Geometries;

(1) Geometrical Format:

(a) Spiral

(b) Concentric

(2) Track Servo Techniques:

(a) Push-Pull

(b) 2 -Spot

If the disk rotates at a constant speed, and the data are written at a constant rate in

bits per second, the bit density within a track will increase with decreasing track

radius. This is the constant angular velocity (CAV) recording. An alternate

approach is to adjust the writing rate as a function of the track radius so as to

maintain a uniform bit density or constant linear velocity (CLV) on each track. This

approach offers a potential doubling of the disk capacity, but is avoided because of

the difficulty in implementation.

B. Review of Disk Speed Factors

(1) Constant Rotational Speed or constant angular velocity (CAV):

(a) Angular bit density is constant

57
(b) Linear bit density varies, and is limited by the bxt density on the

innermost track

(c) Easy to implement

(d) Low data areal density

(2) Constant Linear Density or constant linear velocity (CLV):

(a)

(b)

(c)

(d)

Error Management

Error management involves the choice of the modulation scheme and the use of

Error Detection and Correction (EDAC) techniques. In addition, write verification can be employed, in which data are reread and checked against the original. This

may be done in real time using the Direct Read After Write (DRAW) technology.

Write protection can be achieved through the use of a write-protect flag.

Correction and updating of previously written data can be done by flagging the data

and appending a jump to the location of the new data.

One method of performing the DRAW operation is to use two laser beams, one

slightly behind the other. The second beam reads the information written by the

first, allowing a 10 nanosecond decision time for detecting errors. The second

method (one beam) utilizes the trailing edge of a read signal obtained during the

writing process. The read signal shows a characteristic excursion as the result of

writing a bit (mark) (see f^. 3).

C. Review of Error Management

(1) Modulation Scheme

(2) EDAC

(a) Degree of sophistication depends on the media raw error rate and the

desired bit error rate

(3) ECC requires

(a) Disk real/estate

(b) Encoder/decoder and error generation/correction electronics

(4) Write Verification/Protection

(a) Real time verification by DRAW

(b) Write-protect flag to protect written field

(5) Data Correction/Update

(a) Post field for correction/update within the sector

(b) Vector field for pointing to correctly written new sector

Rotational speed varies, lowest speed when addressing outermost track

High data areal density

Rotational speed change from track to track increases access time

Difficult to implement

58
Summary

(1) The disk determines the drive design.

(2) The disk must provide format (disk firmware):

(a) Tracking information

(b) Addressing information

(c) Clock information

(3) Data error management (disk software) includes:

(a) Modulation scheme

(b) EDAC

(c) Write verification/protection

(d) Update and correction capability

59
60
A/4

TRACKING TECHNIQUES

Shaded area indicates beam position. The pregrooved track

depth is X/8 in the data field with the depth of the

header bits at X/4 depth.

Figure 2,

(Chen - Optical Peripherals Laboratory)

61
DRAW

DIRECT-READ-AFTER-WRITE

(1) TITO BEAM

DRAW BEAM

READ AND

imiTE BEAM

TRACK MOVING

DIRECTION

(2) ONE BEAM

READ, WRITE

AND DRAW BEAM

TRACK MOVING

DIRECTION

Figure 3.

(Chen - Optical Peripherals Laboratory)

I

62
1.2.5 RECORDED CHARACTERISTICS - FILE

STRUCTURE AND LABELLING

By Kenneth Nolan

IBM Corporation

Key words: architecture; compatibility; files; interchange; software.

Introduction

Mr. Nolan described a set of architectural layers related to the use of traditional

magnetic direct access storage devices and their media.

Architectural Layers

(1) System-related

(a) Disk Drive Operation (Physical and Mechanical Properties)

(b) Adapter/Controller Protocols (Bus Interface, Commands, etc.)

(2) Media-related

(a) Unrecorded Media Characteristics (Physical, Mechanical, and Electrical

Properties)

(b) Recorded Media Characteristics (Encoding, Density, Track Layout and

Format, CRC/ECC, etc.)

(c) File Structure and Labelling (Volume ID, Space Allocation, Data

Management, etc.)

(d) File Content (Actual Data Exchange)

Mr. Nolan pointed out that the boundaries between these layers were, in some cases,

arbitrary, but that they provided a useful way of viewing such devices for

standardization. He showed that this view was equally relevant for discussions of

OD^ standards.

He pointed out that standardization of any particular architectural layer of the

optical media was only useful for data interchange if the lower-numbered layer was

also standardized. He also observed that the 'File Content' layer was essentially

media independent and should not be considered specifically for OD^.

Mr. Nolan discussed a number of technical considerations for the 'Recorded Media

Characteristics' and 'File Structure and Labelling' layers and gave his view on the

following compatibility issues.

Compatibility Issues

(1) Software compatibility with traditional storage devices

(2) Consistent architecture for various sizes of optical media

(3) Media independence (architecture not tied to drive/media geometry)

(4) Potential functional enhancements

63
He began by emphasizing that compatibility of 0D3 with traditional storage devices

would be very desirable from the standpoint of software architecture. Such

compatibility would work to minimize software modifications for attachment of new

devices.

He pointed out that a consistent architecture for various sizes of optical media

would allow a given system to attach a number of different devices without

significant incremental software expense.

He discussed the classical tradeoff between media-independent architectures, such

as fixed-block architecture, and those using self-identifying data recorded in terms

of cylinders, tracks, and sectors. He concluded that, for standardization of

removable storage media, the latter provided a more reasonable approach.

He described functional enhancements such as automatic audit trails suggested by

the non-erasability of the media and observed that these techniques would be

difficult to standardize. Data interchange would likely be encouraged by a

relatively simple architecture.

64
1.2.6 QUALITY CHARACTERISTICS OF

OPTICALLY RECORDED DATA

By Miguel Capote

Optical Coating Laboratory, Inc. (OCLI)

Key words: bit error rate; inverse power plots; media performance; media testing;

reflectivity; signal to noise ratio.

Introduction

Mr. Capote presented his topics

(1) Delta AR and Inverse Power Plots (see fig. 3)

(2) Noise - Four Types (see fig. 4)

(3) Resolution (see fig. 5)

(4) Drop-outs and Drop-ins (see fig. 6)

Delta AR and Inverse Power Plots

Mr. Capote discussed the absolute change in reflectance, AR (see fig. 1 and

definiti<His f^. 2), which occurs when the data are recorded on an optical disk. He

proposed the use of the inverse power plot as a more useful characterization, rather

than the traditional plot of detector output versus writing power (see fig. 3). This is obtained by plotting AR in percent against the reciprocal of the write power P. He

pointed out that AR and Pthreshold useful design parameters (see definitions

f^. 2). Ar is independent of the gain of the system. Pthreshold point where

the inverse power plot intercepts the horizontal axis (see fig. 3).

Noise

Mr. Capote identified four types of noise (see fig. 4):

(a) Low frequency peak noise - observed during prolonged peak output signal.

(b) Low frequency trough noise - observed during prolonged zero-level signal.

(c) High frequency peak noise - observed as amplitude variation of peaks

among closely spaced bits.

(d) High frequency trough noise - observed as amplitude variation of troughs

among closely spaced bits.

AH noise types are evaluated in the same way, namely:

SNR = -20 log (<t/AR)

This parameter can be directly related to error performance from the user

standpoint.

65
Mr. Capote used waveforms of closely-packed signals to illustrate the effects of

overburn and underburn during writing. Overburn causes the baseline amplitude

level to shift upward; underburn causes a decrease in peak amplitude. In either

case, there is a loss of useful signal amplitude (see fig. 5). He also used waveforms

to illustrate dropouts and dropins. He noted that most errors are small and widely

separated (see fig. 6).

ASSUMPTIONS:

pi

. Irradiance (I) threshold hole formation mechanism

. No diffraction*

threshold

POSITION

Most media behave this way,

*For discussion of diffraction effects, see C, Carneglia,

Applied Optics, to be published.

Figure 1,

(Capote - Optical Coating Laboratory, Inc.)

66
It can be shox^m that the following approximation holds*

\^ere

AR = Measured change in reflectance upon writing and reading

with a gaussian beam

0% - Perfect Absorber

100% = Perfect Reflector

AR<d = Measured change in reflectance for an infinitely large

hole

P = Write Power

P.. E Apparent threshold Write Power

T

Constant exposure time and linear velocity is assumed.

^Reference: E. V. LaBudde, C. M. Shevlin, and R. A. LaBudde,

Proceedings Topical Meeting on Optical Data Storage, Optical

Society of America, January 1983.

Figure 2.

(Capote - Optical Coating Laboratory, Inc.)

67
INSTEAD OF THIS

A A

Pio

6-S

'—

PS O

w

o

<

H

o

>

OSo

H

o

wH

W

O

A

A

A

P (WRITE POWER)

YOU HAVE THIS . . .

Pi <

1/P (1/WRITE POWER)

Figure 3.

(Capote - Optical Coating Laboratory, Inc.)

68
ooo

CO

bi

COMoo

COo

2: •c

1—1 0

4-1 COu0

CO • c

0) •rl

>-l 4J 3 CO oc 0

•Hu

1—1COa

•H

4-1 a01

<u0a

CO

69
70
71
1»2„7 Panel Discussion: Recorded Optical

Media Unit Characteristics

Panel Participants:

John Bray, NCR Corporation

Miguel Capote, Optical Coating Laboratory, Inc. Di Chen, Optical Peripherals, Inc. Mike Deese, Storage Technology Corporation

John Dove, United States Air Force

Mark Goldberg, National Security Agency

Edward LaBudde, LaBudde Engineering Corporation

Leonard Laub, Vision Three, Inc. Kenneth Nolan, IBM

Yoshito Tsunoda, Hitachi Ltd.

(These Comments are not Transcribed Verbatim.)

Floor: Is there any possibility of format standards, such as for data encoding, error

correction, etc.?

K. Nolan: There certainly is a possibility of format standards and these will be

necessary to permit actual interchange of data. At this time, however, most of the

interest is with the technology.

L. Laub: The subject of format standards is receiving more attention among those

who are adopting video disks for digital applications. There is some question as to

whether these are needed for computer applications.

Floor: While carrier-to-noise ratio is easy to measure, it is not very meaningful.

(M. Capote was asked about the ease of using his waveform measurements.)

M. Capote: This is simply a matter of using an oscilloscope and a ruler.

Floor: A device was once designed for making this measurement by means of a

pattern display.

L, Laub: This is in contrast with the eye pattern used in telegraphy which readily

shows whether any signal excursions occur in the wrong places.

M. Capote: The reflectances I refer to are based on 0 for a perfectly absorbing

medium and 100 for a perfectly reflecting medium. The problem with using contrast

ratios is that they are very deceptive. It is possible to have very high contrast

ratios but signal levels which are not detectable reliably.

M. Deese: What about the relative accuracy of pregrooved media versus servo-written media?

72
D. Chen: The raw error rate is in the range of 10"5 to 10~6 for either process.

However, for one-spot servo-tracking, the media must be pregrooved.

Floor: Would pregrooving reduce the options and deprive a user of possible

economies?

D. Chen: The mastering machine for preparing pregrooved media operates in a manner similar to that encountered in servo writing.

M. Goldbei^: Is format standardization sensible, even if different media v/ere used?

K. Nolan: Yes, especially for manufacturers who produce a number of different

systems. Format standardization permits common software to be used for different

media.

J. Bray: Would it be difficult to arrive at a standard sector length?

Floor and Panel: Yes!

K. Nolan: There could be different sector sizes for the media, but a standard

anchor sector might be used to characterize these sectors. An example of this is the case of 8" (inch) floppy disks. Track 0 is always recorded in 128-byte sectors

and a volume label on track 0 indicates the size of the sectors on the other tracks.

J. Dove: All speakers have been referring only to holes and pits in optical disks as the means of storing information. While that ablative method is the most used, it is not the only way of recording digital and video information. There is the technique

of recording information by forming blisters or bubbles on the surface of the media.

This technique usually involves a thin metallic surface layer placed on a gas forming

sub-layer that forms bubbles when heated by the laser beam. This technique has

significant potential as a laser recording method and should be discussed explicitly

and separately from ablative recording.

Panel: These terms were intended to encompass all technologies.

M. Capote: For panel members responses: Where would you begin to standardize if you were the only designer?

E. LaBudde: Start with the center hole and the mechanical configuration of the

disk. This is important to the manufacturer for tooling purposes, and because of the

related learning curve for each size of disk.

L. Laub: Examine the video disk standards and build on these.

Yoshito Tsunoda: A good point to start with standards would be the direction of disk

rotation, then add the coding scheme, sectoring, and addressing.

Floor: Support for the suggestion for standardization on the direction of disk

rotation was received from those who were concerned with reading both sides of a

disk. Since the ability to read both sides adds greatly to the complexity of the drive

design, one scheme is to remove the disk and turn it over. This could lead to a requirement for being able to read backwards.

73
L. Laub: It is very difficult to achieve a double-sided reading capability, and this

could lower the disk yield. There isn't much user requirement for this.

Floor: Two-sided disks are valuable for mapping requirements.

K. Nolan: There has been little demand in the marketplace for magnetic "Flippies"

which are floppy disks that are turned over to be read on the reverse side.

D. Chen: Regarding OD^ data format standardization, it is important to start with

a good set of OD^ definitions. Then work on standardizing the data format,

addressing the use of spiral or concentric tracks; whether to use pregrooved or servo-written tracks; and the sector size.

K. Nolan: To gain perspective on 0D3 data format standardization, refer to the

architectural hierarchy as it was described in my earlier presentation, 1.2.5, Format

Labellii^ and File Structure Concepts. A range of requirements exists for various

0D3 applications. These differing requirements may result in a number of different

standards. For instance, there may be a need for different standards for the "high

and low" ends.

Floor: The comment was made that users needn't care about mechanical details if the device works well. This was challenged by users who felt a strong need to be

involved and to participate in the standardization process.

74
1.3 SESSION III PRESENTATIONS AND DISCUSSIONS - OPTICAL

DIGITAL DATA TRANSFER AND COMMAND INTERFACES

1.3.1 CHARACTERISTICS OF THE HOST

COMPUTER I/O INTERFACE

By William Burr

National Bureau of Standards (NBS)

Key words: backplane bus; bus; bus structure; device; device interfaces; peripheral

bus; subsystem.

Introduction

Mr. Burr used a variety of computer configurations to illustrate storage and

peripheral device interfaces within computer systems of various sizes. In the

typical mainframe computer, the memory controller is the central element of the

system and there are often multiple parallel paths to the banks of main memory and

to the peripherals (see fig. 1).

In the mini or micro multicomputer system, the backplane is the nexus of the

system. Various components of the system interface to the backplane bus via Direct

Memory Access (DMA) ports (see fig. 2). In the small personal computer, the

mother board bus is the central interconnecting element (see fig. 3).

Where are the opportunities for standards?

Memory and Backplane Buses

In the mainframe computers, the memory bus is ruled out as a potential standard,

since memory buses are peculiar to each mainframe computer and, individual

memory buses do not necessarily connect to all memory modules; it is therefore

necessary to work with controllers through peripheral buses. In small systems, the

backplane bus is the traditional interface point.

There are many candidate backplane buses (see fig. 4). These range from 8 to 64

bits in width and are listed below:

(1) SlOO - IEEE 696

(2) VME -IEEE P1014

(3) Versabus - IEEE P970

(4) STD bus - IEEE P961

(5) Multibus - IEEE 796

(6) Unibus

(7) Q bus

(8) Eurobus

Peripheral buses are generally 8 or 16 bits wide (see fig. 5).

75
Device Interfaces

Device interfaces are specific to the associated devices, and many device

characteristics show through the device interface. Devices have a range of

capability and are characterized as dumb, semi-intelligent, or intelligent. The

architectural levels involved in interfacing a device to a peripheral bus are as

follows (starting from the bus): DMA, Control, Formatter, Data Separator, Device,

The degree of intelligence in the device determines where in this path the

separation occurs between the device and the controller (see fig. 6). While device

level interfaces are important in magnetic disks, they are difficult for users to deal

with, and imply a separation of device and controller, which may not be appropriate

in the emerging world of VLSI technology.

Peripheral Buses

Peripheral buses have a broader usefulness than either backplane or device level

interfaces, and are the traditional interface type available on mainframe computers.

The FIPS PUB 60-1, I/O Channel Interface is a peripheral bus which offers an

excellent opportunity for the optical digital data disk. It has a comparatively high

transfer rate, is available in 80 percent of the world's mainframes, has existed for a very long time, and probably will not change substantially for the remainder of the

decade. Mr. Burr felt, however, the traditional "count, key, and data" technique

described in FIPS PUB 63, Operational Specifications for Rotating Mass Storage

Subsystems, a variable block structure, is probably not appropriate for optical disk

systems. A fixed block structure is also available and is described in FIPS PUB 97,

Operational Specifications for Fixed Block Rotating Mass Storage Subsystems. He

strongly urged consideration of a fixed block structure (see f^. 7).

In the future, Mr. Burr sees the Intelligent Peripheral Interface (IPI) as a mainstream interface for OD^ systems, which, since it uses a 16-bit transfer path,

is basically twice as fast as the I/O channel, and uses half as many signal lines. IPI should soon be an ANSI standard. See f^. 8. Another candidate interface for

smaller systems is the Small Computer System Interface (SCSI), previously having

the proprietary name "SASI" (see f^. 9). The SCSI is already used by at least one

early optical disk product.

For related terminology, see table 1.

76
77
(0 (/> M)

o 2 =>

Q.

^ E

•4

S 0)

o

o

il

c

c

c

a

c

is 4»

Peripl

Coni Un

Device Interface

IL Jl

0)

si" c

o

o

if) </> 00 m

o o

E E

0)

:§

fl) si

o

o

E

Q.

E

o

o

E

CO

c

"5

CO

n3 'OC

4-)

O

3

CO

(U

PQ (0

o

Q. ^

+J

O

2

Si

0)3

CD

(U3

bO

•H

PC4

3

pq

78
79
9 o ^ o 2O

(D r>

(0cO

CO « ^ o E o E " oo < • 5 ^ SI ° C C CO c o

(A P

(0o

"O< Oo

ino o

0)3 CO n

0) ^ i ^— o^

•fc E

T9 CO 0)c

(0

CO oo

(0

<ooo 0) o 3M

•H

fa 5 "O X3 C C C o (B n

t3 « < ^ CO O g 8 „

"S 3 i2 2-2 ^ o ^

>» CO £ A a> Q. ^ ? i O o ^ 5 .E a « CO = ~ >% <0 ^ $ 9

Q. < X I I I I

cn T3uuC

CO

4-1

COU

COCoH

4-1 CO 2

S-i 3

PQ

80
CO

V <D

O

Q. <

(03

75

^3

!-i Idc

4-1 O

TM pq Q-l4-1 CO

0)

(in PQ

(A

a>

(A

O

O I. 5 ^ 0 c^

CO

JC o

.9- 5

Q. « O

i_

t. 0>

0) £ 3 CQ

Q. »- 1 » o in cc u o o O CD E

a>

2: >»

CO (A

CO ^ £o I(0

kl

u

COu

CO3nco

CO Q>

CO

C

a> CO ^ — E « = CO o oc c w

.2

w

.i2 ^

Q. 0> o o

CO COE

0)u

COCO ^oooo

Q. o

.S2 a> >o

COE

CO

COEE

CO 10 (D £ Q.

a> o o

*^ £ Q. I I I I I I

81
c

n

E

o o U (B > r

9 0

(/> lu a. < DC < t- o ec Q<»-<

o ec Z < »- (- lu BC

oozi-iro-i

E

(0

iz

ii.Ocez<i-i-ujec

OOZKKO-'

o

00 Q.

o

c

U.O(CZ<>-HUJC

TVTS

UOZt-OCO-i

oz<

(0

(1)3

0)

a

O Q

> > !r 0) 0) d> O TJ "5

CO "° (B = s - ^

w oc «

a c f

2 8.S

u c 0) ^ ^ m O ^ 2

(/) ffi o

c

CDu

CO>t

CB

» ^ = CO

CO "O

CD C

c —

CO >. « «

i S

.2 0)

> "D

"D ^

d> k. CO o 3 >

I I I I I

82
Computer

I/O Channel

_<^an._Swilch_

Control Units or Storage

Directors

i T-""-

1 -

Control

Unit

^

I

A Unit or

String Controller

A Unit or

String Controller

B Unit

. Not an ANSI standard, developed by X3T9 but rejected by X3, however has

been adopted as a Federal Information Processing Standard (FIPS 60).

. Companion "Operational" specs give Count, Key, and Data command set for

disl<s (FIPS 63) and tape command set (FIPS 62). There also is a companion

power control interface (FIPS 61). A fixed block disk command set has been

adopted as FIPS PUB 97.

. All signal lines go out from computer or in to computer; there are no

bidirectional lines.

. Single ended open emitter signals.

. With "Data Streaming" feature, can transfer at up to 3 Mbytes/s.

. "Normal" version uses 2 cables, each with twenty-four 92 ohm coaxial lines,

and 38 signals.

. Lockout chain arbitration of interrupt requests.

Figure 7. FIPS 60 I/O Channel Interface

(Burr - National Bureau of Standards)

83
Host/

Controller

. Connects host to up to 8 units in master/slave mode.

. Eight or sixteen bit bus for data transfer.

. Two 8-bit buses (in and out) for commands and status speed protocol and

status presentation for fast path switching.

. High transfer rate (up to 5 Mbytes/s) over relatively long cables allows use with high performance 14" disks.

. Four proposed electrical/cable configurations, all single ended, with 24 mA

tristate and open collector, 100 mA open collector, and 100 mA open emitter

drivers and maximum cable lengths of 3, 15, 5, and 125 m (meters).

. 24 Signals

. Central, prioritized arbitration of interrupt requests.

. Includes command sets for common peripherals.

Figure 8. Intelligent Peripheral Interface

(Burr - National Bureau of Standards)

84
. Connects up to 8 computers and peripheral controllers.

. 8x8 connectivity

. Max rate up to at least 2 Mbyte/s asynchronous, 5 Mbytes/s synchronous: suitable

for floppy disks, all 5-1/4" and 8" Winchester disks, medium performance

(e.g., SMD) 14" disks, and streaming tapes.

. Relatively high level peripheral command set.

. Single ended version: 50 conductor flat ribbon cable, up to 6 m, 48 mA drivers.

. Differential version: 50 conductor flat or twisted pair cable, up to 15 m,

EIA RS-485.

. Distributed bus arbitration

. Includes command sets for common peripherals.

Figure 9. Small-Computer System Interface

(Burr - National Bureau of Standards)

85
Backplane Bus - A bus connecting main memory CPU's, single board computers,

other processors, and DMA controllers. Backplane buses make provision for

addressing each memory word with each transfer cycle. Backplane bus standards

also invariably include mechanical printed circuit board standards as well.

Bus - A linear signal path connected to three or more attachments. Distinct from

radial or point-to-point connections.

Computer - The central processor and its main memory.

Control Unit - Presents the I/O bus with a relatively high level logical interface to

the storage subsystem and connects to devices through a lower level Device

Interface. CU's are typically microprogrammed units and may contain significant

amounts of buffer memory. Also called Controller.

Device Interface - A relatively low level interface, usually peculiar to a particular

type of device between a control unit and a device. With intelligent peripheral

device interfaces, becoming more similar to peripheral buses.

Device - A single storage unit such as a disk drive or tape drive.

Data Encoder - When writing, the data separator combines separate clock and data

signals to create a serial pattern of flux reversals which contains both the clock and

data, i.e., a "self clocking code."

Data Separator - Data and clock signals are stored together in the form of flux

reversals in a magnetic surface. When reading, the data separator breaks the

recorded pattern of flux reversals into separate data and clock signals. The data

separator may be in either the device or the control unit.

Formatter - Data are ordinarily recorded in a predetermined format typically

including gaps, synchronization fields, ID fields (often containing flags for bad

recording areas), the data to be stored, and error detecting or correcting codes. The

formatter adds these needed fields when writing data and removes them when

reading data. The formatter has generally been a control unit function in existing

subsystems; however, newer "intelligent" devices may contain the formatter.

Intelligent Peripheral - In the past, the tendency has been to remove most electrical

logic from individual devices and put it in a controller. This allowed the expensive

logic to be shared between several devices. With the advent of LSI, it is now

practical to move some logic formerly in controllers into devices. Very high

recording densities require that the data separator be in the drive. At a minimum,

intelligent peripherals have the data separator and formatter at the device, and may

also have buffering and error detection/correction logic as well as relatively high

level command sets.

Table 1. Terminology

(Burr - National Bureau of Standards)

86
I/O Bus - Connects the computer to peripheral subsystems. In some computer

systems, the I/O bus is also a backplane bus (e.g., UNIBUS of the PDP-11) which also

connects the processor to its main memory. In other systems, this is a separate bus

with a separate memory port (e.g., the FIPS 60 I/O Channel). For the purpose of

this discussion, backplane buses, peripheral buses, and system buses may all function

as an I/O bus.

Peripheral Bus - A bus which connects a single host/computer to several peripheral

devices, with an interface which is broadly applicable to a range of peripherals.

Unlike backplane buses, a peripheral bus does not carry memory addresses. Unlike a system bus, a peripheral does not facilitate host-to-host communications.

Subsystem - The combination of a control unit plus one or more attached devices.

Synonymous with "unit" in the IPI terminology.

System Bus - A bus which directly connects hosts and peripherals and allows direct

host-to-host, host-to-peripheral, and peripheral-to-peripheral transfers. Unlike a backplane bus, a system bus does not carry memory addresses. Unlike a peripheral

bus, any bus port can "talk" to any other port thus facilitating host-to-host

communications.

Unit - The term "unit" is widely used in various interfaces with rather different

meanings. Although unit is not used in FIPS 60, it is in common usage in I/O channel

compatible systems to mean a single physical box containing one or more peripheral

devices. In the IPI proposal, unit is used to mean the combination of a controller

and one or more devices. In the SCSI, a "logical unit" is a peripheral device.

Table 1. Terminology (continued)

(Burr - National Bureau of Standards)

87
1.3.2 OPTICAL DEVICE LEVEL CHARACTERISTICS

Which can Help Determine Interface Selection

By Robert Bender

Storage Technology Corporation (STC)

Key words: device control; host computer; interface; optical storage unit (OSU);

storage controller.

Introduction

Mr. Bender began with an illustration showing how a bank of Optical Storage Units

(OSU) might interface to a pair of host computers through a pair of storage

controllers. The OSU's and controllers would be dual ported in this configuration

(see f^. 1). He visualized an interconnection consisting of the host computer, a

storage controller, a device control, and the OSU (see fig. 2). The device control

would incorporate the intelligence to perform such functions as read/write, EGG,

data buffer, band index memory, and band index look-up (see fig. 3).

Optical Device Characteristics

(1) High density/capacity

(2) Long media storage life

(3) Removable media

(4) Permanent, non-erasable storage

(5) High data reliability

(6) Random access

Mr. Bender felt that OD^ would be most attractive in those applications which

require: large file sizes, a moderate rate of data additions, both good random and

rapid sequential access, long data retention, and high data integrity. He conjectured

that these characteristics would foster the development of a variety of new

applications.

Mr. Bender felt that the inclusion of intelligence at the device level would allow for a multiple choice of interfaces, permit direct attachment to a host, and maximize

product characteristics.

88
STORAGE

CONTROLLER

OPTICAL

STORAGE

UNIT

STORAGE

CONTROLLER

Figure 1. Optical System Configuration

(Bender - Storage Technology Corporation)

89
SOME

INTERFACE

Interconnection: host computer,

storage controller, device control,

optical storage unit (OSU) LOOK AT PRODUCT

CHARACTERISTICS

Figure 2.

(Bender - Storage Technology Corporation)

KEY FUNCTIONS INSIDE DEVICE

TO SIMPLIFY SYSTEM INTEGRATION

• DATA MANAGEMENT

• DATA BUFFER

• ERROR RECOVERY

•DEVICE CONTROL

OSU

Figure 3. Optical Storage Unit

(Bender - Storage Technology Corporation)

90
1.3.3 Panel Discussion: OD^ Transfer and

Command Interfaces

Panel Participants:

Robert Bender, Storage Technology Corporation

William Burr, National Bureau of Standards

Leonard Laub, Vision Three, Inc. Kenneth Nolan, IBM

(These Comments are not Transcribed Verbatim.)

L. Laub: A hierarchy of devices would be present. Off-loading device management

functions from the CPU is preferable. Storage Technology's VSS product was

designed to reduce CPU loading and permit the use of unconventional storage

peripherals.

Floor: Storage management should be off-loaded, but data management should not.

R. Bender: Only a portion of the data management will be in the device.

M. Goldberg: Is it important, when using optical disks in a magnetic tape

environment, to be backward compatible with the existing magnetic tape data

management systems?

R. Bender: Optical storage is complementary to magnetic, not a complete

replacement.

K. Nolan: An effort should be made to treat them (optical and magnetic storage)

identically, as far as practical, but deviate as required. This would be influenced by

the random access characteristic.

Floor: How would the interface requirement for OD^ be affected by the high data

rate?

W. Burr: CPU's are capable of rates up to 24 megabits per second, which would not

be exceeded by OD^.

Floor: What is the current status of erasability of OD^?

K. Nolan: 0D3 erasability is not sufficiently advanced for consideration with

regard to standards.

Mr. Nolan portrayed the following architectural structure of a storage control

system:

(1) Application

(2) Data Management

(3) I/O Control System

(4) Storage Controller

91
(5) Device Control

(6) Device

(7) Media

He pointed out that if the data on the

it can most readily be exchanged

sophistication.

media is as self-identifying as possible, then

among systems with varying degrees of

92
1.4 Summary: Characteristics of an Optical

Media Unit and the Digital Data Channel

Interfaces as Related to Drive Performance

By Edward LaBudde

LaBudde Engineering Corporation

Mr. LaBudde reiterated the workshop objectives, namely, to examine technical

issues, examine application issues, discuss standards possibilities, and determine

directions for 0D3 standards. He noted that the workshop participants were drawn

from among manufacturers, users, and technical experts and had come to realize

that not everyone at the workshop had as much familiarity with 0D3 as had been

anticipated. Therefore, he briefly reviewed the salient characteristics of 0D3

technology.

He stressed the close interrelationship between the media, the optical, and

electromechanical aspects of OD^ systems. He noted the recognized need for a disk

container. Due to the minuteness of the detail on the disk, positioning cannot be

accomplished in an absolute sense but must be done relative to the desired data;

therefore, the disk must contain "road maps" to guide the positioning system.

Mr. LaBudde noted that the OD^ technical issues include the cartridge for

protection against dust and handling; the physics, the mechanical, and the optical

aspects of the disk, the format, whether prerecorded or stamped, and the data

channel. These factors have an impact on the OD^ drives, systems, and

applications.

The focus of the workshop is primarily on what standards are possible and desirable,

and on their impact and their direction. The second and third days of the workshop

emphasize this focus on standards.

The issues related to OD^ standardization are complex because of the

interrelationships between the cartridge, the disk, the data channel, the system

interface, the file structure, and the environment.

According to Mr. LaBudde, a selection method for arriving at the characteristics of

OD^ that require standardization, could include the following three categories:

Type of parameter Philosophy Performance

Number of parameters Knowledge/Exercisers Cost

Definition Application Reliability

Verification

Interrelation

Tolerances

Alternatives

93
2. DAY 2: Thursday, June 2, 1983 - APPLICATIONS FOR

DIGITAL OPTICAL STORAGE AND TEST METHODS

FOR DETERMINING RELATIVE MEDIA &. DATA LIFE

2.1 SESSION I PRESENTATIONS AND DISCUSSION - APPLICATIONS FOR DIGITAL OPTICAL

STORAGE TECHNOLOGIES

2.1.1 A LARGE CAPACITY MASS STORAGE SYSTEM (MSS)

At the National Center for Atmospheric Research (NCAR)

By Bernard 0*Lear

NCAR

Key words: mass storage system (MSS), network MSS node.

Introduction

Mr. O'Lear outlined his topics for discussion as follows:

(1) Characteristics of the TBM* system

(2) A Possible Future NCAR MSS

(3) Early stages of the next MSS

(4) Other MSS considerations

(5) MSS expectations

Mr. O'Lear noted that the NCAR computing center exists to support the computing

requirements of the nation's atmospheric research community.

He then proceeded to describe the present TBM system and the proposed transition

to a next generation MSS.

TBM System

The characteristics of the present TBM system are summarized below:

(1) 23-42, 109 bit tapes mounted

(2) 0.8 x 10l2 bits of on-line storage

(3) 31,000 accesses per month (read and write)

(4) 1,250 accesses per day, on a peak day (growing)

(5) 1 X 10^ bits average access dataset size

(6) 0.5 X 109 bits of new data written per day

(7) 1 X lOll bits average data flow per day between disks, tapes, and TBM

(8) 13 X 10l2 bits held by TBM in May 1983 (up from 3 x 10l2 in January 1980)

(9) 3 X 106 dollars spent for hardware

(10) 2.5 X 10^ dollars spent for Ampex maintenance per annum

*TBM (Terabit Memory) is a registered trademark of the Ampex Corporation.

94
(11) NCAR personnel:

(a) 2 systems programmers

(b) 1 MSS librarian

TBM Services

Among the services provided by the TBM are connections to two Cray-lA's,

servicing of other nodes, and a repository for various data types, including archived

weather data, mathematical model data, and program files (see table 1 and figs. 1

and 2). Mr. O'Lear showed the existing and proposed NCAR Network Configuration

(see figs. 3 and 4). They expect to add NSC adapters and will have two file

transport trunks, one trunk for peripheral devices, and one trunk for a special

software package called Data Management Support Package (DMSP). Other plans

include the addition of an advanced vector computer. See fig. 5 for a schematic of a possible NCAR MSS (Mass Storage System).

A Possible Future NCAR MSS

The transition to a next generation MSS (Phase 1) at NCAR could include

installation of the new system using NSC HYPERchannel,* a dual connection

utilizing a Cray-IA and IBM 4341. Extensive testing and software development wiU

follow.

The transition to a subsequent generation MSS (Phase 2) at NCAR was described by

Mr. O'Lear as: building the MSS "node" including the master file directory software,

network access software, and utility software.

The early stages of the next MSS installation at NCAR would initiate building other

software, such as node and network software: network high-level file transport JCL

and network file transport monitor.

Mr. O'Lear called attention to other MSS considerations, including the longevity of

data, noting that it outlasts both the creator of the data and the computer system

that created it. Nineteen percent of bits stored at NCAR are read or written each

month; 46 percent (total bits) are moved for backup and verification; and 35 percent

(total bits) are moved for compress-purge of old files.

Data conversion and data archive planning for various current and future systems

and processes are a major activity at NCAR.

MSS Expectations

The expectations for a future MSS are a data flow of 10^2 bits per day, a data

collection of 10^^ to lO^^ bits, and a data flow rate of 5 x 10^ bits per second. The

MSS archive expectations progress from 3 x 10^2 bits in 1980 to 305 x 10^2 in 1993

(see table 2). The data flow rate over that period will progress from 0.5 x 10^ bits

per second to 21.2 x 10^ bits per second (see table 3). An on-line storage

requirement of 10^2 to 10^3 bits will exist in the 1985-1987 time frame, growing to as much as 10l6 bits in the late 1980's to early 1990's. A media life of 2,000

HYPERchannel is a registered trademark of the Network Systems Corporation.

95
retrieval/load/read/unload/replace cycles is required, with a cost goal of $.015 per

10^ bits of information. The unrecoverable bit error rate should not exceed 1 failure in lOH bits. Therefore, for physical records consisting of 106 bits, no more

than one record in 100,000 records should fail (see tables 4 and 5).

Discussion and Conclusion

Mark Goldberg who moderated the panel discussions in this session, entitled

"Applications for Digital Optical Storage Technologies," noted that this session

presented an opportunity for users to express themselves, and that the panel

included individuals who could help assess the impacts of a particular user's

requirements on the OD^ system designs and the related standards.

Panel Participants: Di Chen, Optical Peripherals Laboratory; Mark Goldberg, NSA

(Moderator); Edward LaBudde, LaBudde Engineering Corp.; Leonard Laub, Vision 3.

Mr. LaBudde noted that the NCAR application was well suited to optical disks, in

that it required high capacity, relatively modest transfer rates, and a reasonable

data access rate. The file usage exhibits a low duty cycle, lending itself to the

loading and unloading of disks on spindles. He also noted that the key requirement

with regard to standards is for media interchangeability among spindles.

Mr. O'Lear remarked that they mail out data sets (disks) to customers around the

country and therefore would benefit from media transportability/compatibility.

Operational Software

CRAY-1 CDC 7600 TMS-4

Request Function

User Level

System Level

Directory Function

Work Manager Function

MSD Controller Function

1/0 Function

6500A*

550A

0

0

0

1450A

18500A

4000A

0

0

0

3000A

0

13000A

5200A

20000A

39600A

5200A

Support Software

MOVE/COPY and COMPRESS 0

Directory Maintenance 0

Diagnostics 1700A

OPERATING SYSTEM

0

4500Ht

2500A

2100A

2500A

1500A

17000A

10,200A 28,000A 106,100A

4,500H

* = Assembly

t = High Level

Table 1 (O'Lear - National Center for Atmospheric Research)

96
TOTAL VSNs ON THE TMS-4 SYSTEM AND TOTAL

BITS MOVED BETWEEN THE 7600, CRAY AND TMS-4

(total off bits read and written)

4

0 """""""""""""""""""""""""""""""" "" FAJAODFAJAODFAJAODFAJAOOFAJAODFAJAOO

1977 I 1978 I 1979 I 1980 I 1981 I 1982

Figure 1.

(O'Lear - National Center for Atmospheric Research)

97
98
E

0)

Q >

r. > o < ro DC m O zo< lij CC </) 3 O — O CLO § z tr 2: O I

oc < 1g

$z &

IK «^

ULl o

CD < o _

CN CO

CM< - o _

CN

O < - o _ < - o _

CM < - o E

to> U < o _ < -

ro<o _ 1^ T- 5 o S E E

0)

Q > o c

0) E E

in o a

CN o n >

_i o

SE § Q

Net j

and

1/34 j O _ hies) t

't -a- < -

DEC 1

(Grap o

1^

O< uLU I Q

D)C

'«

I/) (U in oo

dl

n ni _J

(S SE QQ<U< oumo

•Hoe<o

Z3 (-1 fcC 01 •H i-i

01 O

n3CO

•H

4-1 C^

CO

99
100
Optical

Controller

( MSS \

V NET ;

R RW

JUKEBOX

RWj

n1 R |rW

JUKEBOX

1 R RW

RW

JUKEBOX

R RW

Optical

Controllar

^To TBM^ MASS

STORE

CPU

Master

File Directory

Local NCAR Network

ADVANCED

VECTOR

COMPUTER

^Secondary

Storage

A POSSIBLE NCAR ODMSS

Figure 5.

(O'Lear - National Center for Atmospheric Research)

101
Net Rate of Data In NCAR Archiving Data Archive

Year Compute Power (1012 bits/yr) (1012 bits)

1966 .3 (CDC 6600) (at end of year)

1968 .6 E.08

1971 3.3 (add CDC 7600)

1976 3.0 E.27 1.5 (tapes)

1978 8.3 (add Cray-IA)

1980 11.6 (Cray efficient) 3.3 3.0 (MS*)

1982 11.6 3.3 10.0 (MS)

1984 20.0 (2 Cray's) 5.7 20.0 (MS)

1986 70.0 (Add AVC) (19.9) 19.0 45.0 (MS)

1987 100.0 (28.4) 24.0 69.0 (MS)

1992 100.0 (28.4) 32.0 214.0 (MS)

1993 400.0 (new machine) (114.3) 90.0 305.0 (MS)

*MS = Mass Store

Table 2. MSS Archive Expectations

(O'Lear - National Center for Atmospheric Research)

Net Rate of

Archiving User Bits Aver. Bit Rate

Year (10l2 Bits) 10l2/Year 106/Sec.

1980 3.3/Yr 15 .5 1983 4.0 31 1.0

1984 5.7 44 1.4

1986 19. 143 4.5

1987 24. 182 5.8

1993 90. 670 21.2

Table 3. MSS Data Rate Expectations

(O'Lear - National Center for Atmospheric Research)

102
Jr cttK.

1^NToV7« jril Arr>hivp V'l IX V ^ Tf* 11 ijiiic:'Cti T .in^^op r\L, lUcll jr\ A OPPQQPQ \_, I- OoCo With Spt<? Don T-Trkiii* idPpr Hnnr i LKJXAI.

Dec. 1982 58,000 22,600 22,600 30.9 309

Dec. 1984 116,000 45,200 40,000 55.0 550

Dec. 1986 261,000 108,300 130,000 178.0 1780

Dec. 1987 400,000 155,900 165,000 226.0 2260

Dec. 1993 1,769,000 689,000 610,000 834.0 8340

Table 4. Expectations (continued)

(O'Lear - National Center for Atmospheric Research)

Actual Datasets

Rate of Adding

Datasets

Feb. 1977

Oct. 1978

Aug. 1979

Aug. 1980

Dec. 1982

Projection

Dec. 1984

Dec. 1986

Dec. 1987

Dec. 1993

0

9,300

15,000

27,000

58,000

116,000

261,000

400,000

1,769,000

7,000/Yr

10,000

12,000

15,000

26,000

86,000

109,000

409,000

Table 5. MSS Dataset

(O'Lear - National Center for Atmospheric Research)

103
2.1.2 A MODERATE CAPACITY MASS STORAGE SYSTEM (MSS)

By Paul AUison

U.S. Army Materiel Devel(^ment and

Readiness Command

Key words: aperture card scanner; CAD/CAM; graphics terminal; printer (high

speed); plotter.

Introduction

Mr. Allison described the emerging Digital Storage Retrieval Engineering Data

System (DSREDS). According to Allison, "DSREDS" is a state-of-the-art system for

digital storage, update, retrieval, dissemination, and duplication of engineering

drawings and documentation.

The DSREDS System

DSREDS is being developed by the U.S. Army Materiel Development and Readiness

Command (DARCOM). DSREDS will store and provide access to a large and growing

quantity of engineering drawings (see f^. 1). The standard system will scan and

digitize drawings which are currently on hard copy and aperture cards. Future

drawings can be accepted electronically in digital form directly from weapon system

contractors. Digitized drawings will be verified for quality and integrity, processed

by a system controller and permanently stored on optical disk. When needed, they

will be retrieved and output as aperture cards, provided as hard copy, or transmitted

to remote graphics terminals for review and verification. DARCOM presently has

4.2 million aperture cards, containing 35 mm film images of engineering drawings.

Without new storage technology, the current system capacity will be insufficient by

1986. The number of drawings are expected to approach 14 million by the end of

this century (see figs. 2 and 3). Much of the present equipment incorporates the

early 60's technology, and it is feared that an irreparable breakdown of the system

could occur in the next two or three years (see fig. 4). The current system relies on

mail and courier systems for transferring drawings among subordinate commands

and other activities. Preparation of technical data packages is presently slow and

inefficient.

DARCOM's technical data mission is to maintain archival drawings and technical

documents, to assemble technical data packages for procurement, and to provide

technical data support to engineering personnel.

The technical data mission is supported by technical data/configuration management

systems and archival drawing/document storage and retrieval systems, including

Mosler/Infodetics automated aperture card systems. Dare automated film chip

system, and hard copy/mylar manual systems.

The equipment currently being used by DARCOM for this production has the

following problems:

(1) It is based on early 60's technology.

104
(2) Some of this equipment is no longer supportable, with replacement parts

becoming scarcer.

(3) Its maintenance costs are increasing 10-15 percent per year, as the older

units are becoming increasingly less reliable.

The future plans include the scanning and digitization of aU drawings which are

currently in hard copy or aperture cards. Future drawings will be accepted

electronically in digital form, directly from contractors, and will be stored on

optical disks. They can then be output as needed on aperture cards, hard copy, or transmitted to remote graphics terminals for editing and subsequent storage.

Design goals are for a peak input rate of 2,500 drawings per hour and a peak output

rate of 9,600 per hour. Repositories at seven sites are planned, for redundancy.

DSREDS Requirements

DSREDS requirements are summarized as follows (see fig. 5):

(a) Optical disk-based mass memory - stores 2 x 10^ expandable to 4 x 10^

digitized engineering drawings and documents averaging 1 x 10^ bits of

data each.

(b) Optical read only - accepts manual load of disks from mass storage unit.

(c) Process controller - controls all system component functions.

(d) High speed printer - prints 1000 lines per minute on 378 mm (14.875 in) by

279 mm (11 in) paper.

(e) Magnetic tape storage - provides for dual-density 9-track digital magnetic

tape recording and reproducing.

(f) Magnetic disk storage - provides for data management and temporary

storage of digitized data.

(g) Master control operator console - provides for dialogue between the system

operator and the DSREDS system. Provides hard copy output.

(h) Data integrity control - provides for data file analysis for document

validation prior to commitment to permanent file.

(i) Data compression/decompression - compresses data for optimum storage

and decompresses data for output to peripheral devices.

(j) Communications - permits interaction between process controller and a

variety of external devices,

(k) Plotter - provides A-K engineering drawing hard copy with resolution equal

to the original; accepts raster and IGES data.

(1) Aperture card scanner/duplicator - scans at 240 cards per hour with

8 points per mm (200 points per in) resolution,

(m) A-K drawing scanner/duplicator - scans D size drawing in 3 minutes with

200 points per inch resolution,

(n) Computer output microfilm - images digitized data with 8 points per mm

(200 points per in) resolution,

(o) Aperture card output - contact prints negative silver roll microfilm to

35 mm diazo cards at 2500 cards per hour,

(p) Aperture card duplicator - reproduces/interprets 9,600 cards per hour,

(q) Graphics terminal - displays complete E size drawing with 1700 x 2200

pixels resolution; accepts raster and Initial Graphics Exchange

Specification (IGES) data; provides hard copy output,

(r) Alphanumeric terminal - provides 16 inch screen with optional hard copy

output.

105
DSREDS Benefits

Anticipated benefits of the DSREDS system include the following:

(a) Capacity for projected increase in engineering drawings.

(b) Reduction of administrative lead time (ALT).

(c) Reduced maintenance costs/downtime.

(d) Disk storage at multiple sites for continuity of operations.

(e) Transmit drawings electronically.

(f) Drawings can be viewed electronically at remote sites.

(g) Less space requirements.

(h) Transmit technical data packages (TDP) electronically to contractors.

(i) Interface with CAD/CAM systems.

(j) Improved productivity for engineering changes,

(k) Transmit engineering change proposals.

Conclusion

In summary, optical disk technology can avoid total system breakdown, by replacing

aging systems and accommodate the increasing drawing storage needs in the mid and

long term. According to P. Allison, the DSREDS acquisition program is cost

effective and can pay back hardware/software costs in under 2 years.

Discussion

Mr. Laub called attention to the possibility of storing digital data from a CAD/CAM

process, rather that fully digitized images. This is a highly compressed

representation of such data. He also foresaw the need for automated cartridge

handling. He did not anticipate any unusual standards requirements for this (U.S.

Army) application of OD^.

He noted that there was a recognized need for transportable media which could be

used for sending stored images to remote sites.

106
107
SNomiiAi Ni S9Ni/vwaa

108
SNOmilAI Ni S9NIMVya

109
CO

LLJ

cn

CD o

UJ o

az<<o

LU

73C

COo

110
SIZE 1

ING NER ^ Z < < D

111
2.1.3 A LARGE CAPACITY DISTRIBUTED MASS

STORAGE SYSTEM (MSS)

By Pat Savage

Shell Oil Company

Key words: floating point operations; geophones; geophysical computations; seismic

computation.

Introduction

Mr. Savage described the typical procedure used for both land-based and marine

geological exploration. On land, a "computer truck" is used to receive data from up

to 240 geophones extending some 3660 m (12,000 ft). An explosive charge is fired in a test hole and the resulting shock waves are sensed at 3 millisecond intervals for

approximately 7 seconds. This test yields some 600,000 data samples, each

consisting of 3 bytes. Marine explorations use a ship which trails 240 hydrophones

on a 3660 m (12,000 ft) cable. Test shots are fired every 10 seconds which result in

the same data rate as above. In 1981, the worldwide seismic work encompassed

312,500 km (500,000 mi) and required 600 crews on land, and 625,000 km (1,000,000

mi) and 40 vessels at sea.

Seismic Computation

The seismic computation load for 1981 consisted of data derived from 937,500 km

(1,500,000 mi) of survey, with 10 million floating point numbers per mile, leading to a computation rate of 1,000 megaflops (millions of floating-point operations per

second), or approximately one gigaflop per year. Two-dimensional analyses involve

the merging of data from a large number of traces; three-dimensional analyses

require a staggering increase in computations.

SEISMIC MIGRATION

(1) 2D Migration

Each result trace partakes of as many as 800 stations

- 1,600 stacked traces

- 96,000 unstacked traces

Computation can be configured to arbitrary I/O-compute ratio

(2) 3D Migration

Each result trace partakes of all stations with radius < 400 station

intervals

- (4002) X Pi = 500,000, stacked

- 500,000 X multiplicity, unstacked

Staggering data storage/access problem

112
Geophysical Computations

Mr. Savage noted that geophysical computations involve correlations, convolutions,

and digital filtering of arrays of data points. Many lengthy sorts are required,

involving tape-to-disk-to-tape transfers. Loss of an individual record is not

critical.

(1) NMO Correction

- Interpolation

- Searching, testing, branching

- Bookkeeping

(2) Correlation

- 100-600 by ditto

- Combinatorial

Convolution

- 100 - 2400 by 150

(3) 2D KF Filtering

- 2400 by 192

(4) Normalization

(5) Multi-trace Processing

- Weighting

1981 World Seismic Work

Miles

Cost

How Gathered

LAND

500,000

$2.7 Billion

600 Crews

MARINE

1,000,000

$1.2 Billion

40 Vessels

TOTAL

1,500,000

$3.9 Billion

Seismic explorations are performed both by corporations and private entrepreneurs.

The latter sell their data to interested parties. New data tapes are received on a weekly basis.

Discussion and Conclusion

It was noted that the proposed application's recording rate would not pose a technological problem for OD^. The biggest problem is sorting, involving the

assembly of 240 records in a batch. It would be desirable to be able to request a batch of 240 records and allow the controller to pull these together in whatever

manner it preferred (see figs. 1 and 2).

113
The operating environment on

board is that of a typical computer

room. The shipping conditions

have a worldwide range, and shock

conditions encountered on

shipboard may require specialized

environmental standards for the

disk.

Mr. LaBudde noted that the

application described by Mr.

Savage has a definite need for a data interchange standard.

SORT

SSP/DIS

FIELD DATA

SHOT/RECEIVER SORT

ARCHIVAL DATA

SSP/DIS SORT

PROCESS 1-2

r

SORT

PROCESS 3

L

SORT

SSP/DIS J

(Savage - Figure 1.

Shell Oil Company)

PROCE!SS 4-8

DISPLAYS

114
Figure 2 CONTINUOUS SORTING -STORAGE REQUIREMENTS

(Savage - Shell Oil Company)

SHOT ORDER-—STATION ORDER

SHOT ORDER—SSP ORDER—STATION ORDER

CASE

-J- TRACES

4

N CASE A CASE B

120 36 M bytes 72M bytes

192 92 M bytes 184 Mbytes

240 144 Mbytes 288Mbytes

384 369 Mbytes 737 M bytes

{10,000 BYTES/TRACE)

115
2.1.4 A CARTOGRAPHIC MAPPING AND DATA

BASE MANAGEMENT SYSTEM

By Ted Albert

U.S. Geological Survey (U.S.G.S.)

Key words: cartographic digital data; data storage capacity; pictorial data;

photographic film.

Introduction

The USGS is building the world's largest collection of earth science and cartographic

digital data comprised of data obtained from land, sea, and satellite. The data bases

include all earth sciences data of concern to the United States, including data

relating to earthquakes, Landsat, coal and other minerals, aeromagnetics, gravity,

and volcanos, water supply and stream flows, etc. The archiving of Landsat data

alone involves lO^^ bits, over five years. Several network services are used as well

as extensive computer facilities. The estimated storage capacity requirement by

1986 will be I0I6 bits.

The primary needs are for reliability, great capacity for modeling, and the ability to

merge data from multiple sources. High altitude and satellite photography yields

pictorial data comprised of many data points. Therefore, the digitizing of the base

map of the U.S., at a scale of 1/24,000, will result in an extremely large digital data

base and will take many years to accomplish.

Storage Requirements and Conclusion

Mapping techniques have conventionally utilized photographic film -oriented

methods for production and updating, and for high density storage. Production and

updating are generally very lengthy processes requiring many months and often,

years. Modern computer technology offers the potential for a transition to

improved methods along with greater utilization of the data and information.

However, in order to move fully into the digital era, a breakthrough in mass storage

technology and spatial data management would be required. For example, one of

the basic digital cartographic files will require an estimated lO^"* bits of capacity.

The laser optical disk appears to be a candidate for handling the great volumes of

mapping data which are required. Further, there is currently no available data base

management system that can handle very large spatial data bases. Artificial

intelligence techniques are being investigated to provide improved data management

methods.

Mr. Albert discussed the relative storage capacities of various media and outlined

the advantages of OD^ for this storage application.

116
2.1.5 A MOBILE PLATFORM APPLICATION FOR

DISTRIBUTED OPTICAL STORAGE

By Jack PetruzeUi

United States Air Force (USAF)

Rome Air Development Center (RADC)

Key words: airborne data collection; durability; interchangeability of 0D3 media;

optical disk environmental considerations, optical disk requirements;

transportability of 0D3 media.

Introduction

Mr. PetruzeUi described the need for an airborne data collection device to store

data for later ground-based processing. The device would be carried in

transport-type aircraft (see figs. 1 and 2).

Rome Air Development Center (RADC)

Durable Optical Disk Requirements

(1) Data Rate

(2) Storage

(3) Data Access

(4) Bit Error Rate (BER)

(5) Size

(6) Weight

(7) Power

0.5 to 20 X 106 bits per second (bursts to

40 X 10^ bits per second)

5 X lOlO bits/disk

500 X 10~3 seconds

10"^ with Error Detection and Correction

(EDAC)

0.057 m3 (2 ft^)

45.4 kg (100 lbs)

110 vac; 50-60 Hz

RADC Durable Optical Disk

Environmental Considerations

(1) Temperature

Non-Operation

Operation

(2) Humidity

Minimum

Maximum

(3) Pressure

Shock

-40OC (-40OF) to 65.50C (+150OF)

lOOC (+50OF) to 37.80C (+100OF)

20% from lO^C (+50OF) to IB^C (+6lOF)

100% (condensing) from lO^C (+50OF) to

27.20C (+810F)

20.58 in Hg or 10,000 ft above sea level

NTE 1.5 g along any axis (MIL-E-5400-T,

para 3.2.24.6)

117
(4) Vibration Sinusoidal dynamic (MIL-E-5400T, Page 31,

Figure 2, Curve II-A Jet Aircraft)

Conclusion

This application requires interchangeability of the 0D3 media among machines,

transportability of media, device operation in/on various platforms, and the ability

to survive air-drop (non-operational). A study contract to characterize the eventual

hardware design has been awarded to RCA Corporation, Camden, New Jersey.

Figure 1, Durable Optical Disc Syste-m (Operational View)

(Petruzelli - United States Air Force)

(Rome Air Development Center)

118
Figure 2. Durable Optical Disc System (Servicing Position)

(Petruzelli - United States Air Force)

(Rome Air Development Center)

119
2.1.6 OPPORTUNITIES FOR DOCUMENT

AND CHARACTER STORAGE

In Commercial Applications

By Le<»iard Laub

Vision Three, Inc.

Key words: accessibility; characteristic record length; cost; data distribution

technologies; storage capacity; technological demand.

Introduction

Existing computer and office automation systems use semiconductor random access memories (RAM's), fixed and removable magnetic disks, magnetic tapes, and

microform as data storage devices. Whether by tradition or through careful

analysis, users and system's architects have determined ways to use these

technologies so that short, new and frequently accessed files are stored in random

access devices such as magnetic disks—while lengthy, old, and rarely accessed files are stored on magnetic tape and microform, both of which have slow data access

but are most capable of compact, low cost storage.

Optical storage equipment need not be configured into a plug-compatible

replacement for any one of these technologies; it is easier and more effective to

provide an integrated storage system, using several technologies that are controlled

by dedicated computing capability, which is assigned to move files among the

storage devices based on changing patterns of access and importance.

Straightforward guidelines for determining how much of each technology to use in a

given application have been developed. This work impacts hardware and media

product requirements and should be considered as part of the process of standards

development.

Data Distribution Technologies

The variety of telecommunication services available to users of computer and office

automation equipment continues to increase as satellite and optical fiber links

become abundant and as wholesalers and retailers of data carrying capacity

proliferate. Enthusiastic predictions of widespread remote searching of data bases

have been made, but economic and technical issues must be resolved. The growth in

computing expected in the next decade cannot be supported primarily by centralized

data storage; the capacity available will not suffice, and the cost per unit data

transferred will be too high. The alternative, just becoming visible in practical

commercial products, is to distribute copies of public and private data bases to users on read-only optical disks. One category of such distribution is also becoming

known as "electronic publishing." Formats appropriate for data base distribution

include both the 30 cm (12 in) LaserVisiontn^ videodisk (capable, using appropriate

channel and error correction coding, of holding up to 3000 MB of weU-corrected

user data per surface) and the 12 cm (5 in) Compact Disc^nfi digital audiodisk, as weU as any of the locaUy writeable formats now under consideration.

Standardization of read-only formats will have considerable commercial importance.

120
0D3 Technological Demand

Mr. Laub's organization, Vision Three, Inc., performs consulting, systems

integration, and business development in optical and other data storage. He sees demand for 0D3 technology due to the following:

(1) Large volume of documents

(2) Desire for rapid random access

(3) Desire for remote access

(4) Desire for computer-assisted access

(5) Desire to merge image and character files.

0d3 Storage Capacity, Costs, and Accessibility

The availability of lower cost CRTs, scanners, and printers, improved file-finding

processors and magnetic disk, RAM, and the availability of optical disks have

enhanced the demand for OD^ technology. Mr. Laub reviewed the relative

capacities of various magnetic storage media versus optical disks. A 356 mm (14 in)

optical disk has a capacity of about 9,400 x 10^ bytes or 260,000 images of A4

document pages. The relative information storage costs for various storage media

were compared. The media cost for OD^ was 3 cents per 10^ bytes or 95 cents for

1,000 images. This latter figure compares very closely with microfilm at 90 cents

per 1,000 images. Relative access times for various media are tens of seconds for

magnetic tape, 0.05 to 0.5 seconds for rotating magnetic storage, and 0.1 second for

optical disks.

Considering accessibility, Mr. Laub noted the high throughput capacity of drives,

with reference to a "characteristic record length." He noted the utility of

hierarchical organization of drive types and stressed the importance of memory

management outside of the central processing unit (CPU), removing this concern from the user. An additional, important requirement is for multi-dimensional

search capabilities.

The characteristic record length, previously mentioned, is defined as that for which

the transfer and access times are equal. It is useful for optimization in a

hierarchical storage structure. Typical values are as follows:

(1) RAM: 1 byte

(2) Magnetic disk: 15-90 x 10^ bytes

(3) Optical disk: 200-1,000 x 10^ bytes

(4) Magnetic tape: 2-20 x 10^ bytes.

Mr. Laub envisioned the possibility of improving accessibility by anticipating a user's

requirements for successive pages of data and files, based on recognized

interrelationships among the data and files. He caUed attention to the fact that,

without proper storage management, the high capacity of an optical disk could lead

to large user queues.

Mr. Laub contrasted the relative costs of transporting data by various methods, both

physical and electronic. Because of the high capacity of an optical disk and the

availability of overnight express mail, the mailing of a disk can be a very

121
cost-effective way of transferring data. For example, 12,000 x 10^ bytes of data can be sent 3,000 miles in 18 hours at a cost of $9.35, for a net data rate of

1.5 X 106 byte/second and a cost, including disks, of 0.4<t!/106 byte.

He described the storage capacity and access rate needed for imagery. He

structured a hypothetical case of a system involving 3 x 106 images on file, having

100 users, each generating 30 requests per hour. The hardware for meeting this

requirement with 0D3, consisting of 108 read-write optical disks, 12 disk drives and

1 automatic media handler ("jukebox"), was stated to be available soon for less than

$100,000, exclusive of terminals, communications, and other processing equipment.

Conclusion

Considering system issues, Mr. Laub discussed hardware and software compatibility,

hierarchical memory architecture, the need for removable media, erasability, and

media transport versus the telecommunication of digital data.

122
2.1.7 PERSPECTIVES OF AN 0D3 INTEGRATOR:

OFFICE APPLICATIONS

By David Fain

Integrated Automation Corporation

Key words: interchangeability; photographic film; pixels per inch; replicability;

resolution; United States Library of Congress; vector storage.

Introduction

Mr. Fain described a large, film-based data system. He stressed the inherent

resolution limits of film, which he felt from a practical standpoint to be about 120

pixels/inch. While higher values may be claimed, they tend not to be achieved and

sustained in a production environment. The processing of photographic film required

to produce a visible image lengthens the production time. This imposes the burden

of having to keep input documents accessible until the processing is completed and

the film is quality-controlled. With an optical disk system, a resolution of 8 to 16

pixels per mm (200 to 400 pixels per in) is achievable, and in some instances reaches

118 pixels per mm (3000 pixels per in). The cost of optical storage was cited to be

lower than for film storage.

Integrated Automation, Inc., has been awarded a contract to provide a system which

will use digital optical disks for computerized mass storage, preservation, and

retrieval of printed materials, including text and halftone illustrations, to the

United States Library of Congress, located in Washington, D.C.

Mr. Fain showed a diagram of the proposed integrated system, illustrating the

incorporation of OD^ technology with data processors, communications equipment,

display terminals, and printers. Data compression at a ratio of approximately 10:1

is being used. He envisioned systems of this type as being well-suited to transaction

processing such as handling remittances. He also envisioned their applications in the

widespread printing of documents and books, on demand. For the input of large

diagrams, he anticipates the use of vector storage rather than raster storage. See

fig. 1, which is the system level diagram of the OD^ information system planned for

the Library of Congress.

Conclusion

Mr. Fain stressed the need for archival storage, interchangeability, replicability, and

reasonable cost per disk, although the latter factor does not seem to be a major

consideration. Regarding OD^ standards, he prefers a maximum of diversity of OD^

products at the present time. He has confidence in the ability to interface diverse

products. Within an installation, interchangeability of the media is needed from

drive to drive. He would like to see the drives designed to provide good access to

the spindle in order to facilitate integration with automated handling equipment

("jukebox" arrangement).

123
124
2.1.8 TECHNICAL REQUIREMENTS FOR

DOCUMENT STORAGE APPUCATIONS

By Gerry Walter

Planning Research Corporation

Key words: bit per pixel; document storage systems; image quality; resolution;

storage requirement.

Introduction

Mr. Walter observed that there is no "average" user of document storage systems.

He distinguished between data and documents. The latter have a post mortem

character and can serve in an evidential role; i.e., as evidence. A legal requirement

for the retention of the original document exists in many government situations.

Microfilm is not considered legal evidence, and it is questionable as to how OD^ will

be viewed in this regard.

Mr. Walter characterized four types of images and indicated their digital storage

requirements, as follows:

Types of Images

Monotone

Bi-Tonal (Digital) Continuous Tone

Chromatic

Partial Spectrum FuU Spectra

Line Drawings

Type, Handwriting

Halftone

- Photos

- Art Work

- Converted

Chromatics

Line Art

Two Color

Conversions

- Orthochromatic

Photos

- Artistic

Pictures

One Bit Per 4 to 16 Bits

Pixel* Per Pixel*

*Pixel = Picture Element

Note: The pixel count remains constant, as determined by resolution. The quantity

of bits per pixel, therefore the quantity of bits per page, depends on the type of

imagery.

Image quality was related to resolution by Dr. Walter as follows:

Note: Ipi = lines per inch

(1) 100 Ipi (16 pixels/mm2) - Marginal

(2) 200 Ipi (64 pixels/mm2) - Provisionally Acceptable

(3) 300 Ipi (144 pixels/mm2) - Good

(4) 400 Ipi (256 pixels/mm2) - Excellent

9 to 32 Bits 32 to 128 Bits

Per Pixel* Per Pixel*

125
The digital storage requirement for documents scanned at various resolutions was

given by Dr. Walter as follows:

100 Ipi 200 Ipi 300 Ipi

(1) Resolution Marginal Satisfactory Good

(2) Bits/Inch2 104 4 x 104 9 x 10^

(3) Bits/Document 9.35 x 105 3.74 x 106 8.415 x 106

(4) Compaction 3 x 7 x 15 x

(5) Net Bits/Document 3.12 x 105 5.34 x 105 5.61 x 105

The storage requirement for 300 Ipi (lines per inch) is so close to 200 Ipi, that one

might as well disregard the 200 Ipi case.

Conclusion

Dr. Walter stated that, in terms of user requirements, the storage and retrieval

system should be transparent to the user. The display should retain aU of the

desirable characteristics that are associated with paper-based storage while

replacing the undesirable ones. Also, the technology should be the most

, cost-effective over its life cycle. As an illustration, using a seven year life cycle,

the cost of a paper system works out to 92 cents per page, for microfilm it is $1.05

per page, and for automated, digital data disk storage and remote CRT display, it is $4-5 per page.

The need for duplicate image carriers in a central data bank system was stressed.

Dr. Walter advocated 1 to 3 working copies and 1 to 2 security copies. He

emphasized the value of having backup copies in the same form as the working

copies. In a distributed image data bank system, he observed that there were

typically from 6 to 30 working copies, 1 master copy, and 1 to 2 security copies. He

felt that these systems outnumber the centralized systems, several hundred times.

There is a need for accommodating the great amount of information that is not

solely generated inside an organization.

126
2.1.9 OPTICAL STORAGE IN AN OEM ENVIRONMENT

By Joseph Zajaczkowski

Sperry Corporation

Key words: applications; original equipment manufacturer (OEM); specifications;

standards development.

Introduction

Mr. Zajaczkowski began by stressing the importance of user input at the earliest

stages of standards development. The extreme reliability required in 0D3

applications was emphasized, and the term YBF (Years Between Failures) was

advocated in place of MTBF (Mean Time Between Failures). He noted the broad

spectrum of standards, specifications, codes, and design practices that an OEM must

deal with, ranging from details of product design to overall system considerations.

Mr. Zajaczkowski referred to standards as both a double-edged sword and a chain

that you drag along forever. Standards remove some of the risk, at the cost of

reducing some of the choices and impacting innovation. There have been cases of

potentially useful products which failed because no one would invest in them, due to a lack of standards.

Problems can occur, even in a well-established field, due to lack of agreement on

definitions, interpretation, and understanding. The language affiliated with

standardization should be kept simple.

127
2.1.10 REQUIREMENTS FOR EASILY DESTRUCTIBLE

OPTICAL MEDIA UNITS

By Mark Goldberg

Nati(Hial Security Agency

Key words: accessibility; compact; destructible; encryptable.

Introduction

Optical disks offer advantages in a secure environment—including data storage in

digital form, which is computer compatible and encryptable. The compact physical

size and rapid accessibility of data stored on disks are other distinct advantages to

0D3. These factors also provide an advantage when transporting data from one site

to another, or when disposing of the data.

Conclusion

Dr. Goldberg described a possible installation as having 30,000 documents, which

would form a stack more than 6 feet high, comprising 20,000 square feet of paper.

On magnetic tape, this would require 30 reels each 730 m (2,400 ft) in length. A

single optical disk of one square foot area could contain the same amount of

information—and unlike the other media, could be quickly disposed of, in response

to a security threat.

128
2.1.11 Panel Discussion: 0D3 Applications and

Standards Requirements

Panel Participants:

Di Chen, Optical Peripherals Laboratory

John Davis, ITTRI

Mark Goldberg, National Security Agency (Moderator)

Michael Hogan, National Bureau of Standards

Edward LaBudde, LaBudde Engineering Corporation

David Morin, Naval Ocean Systems Center

Del Shoemaker, Shoemaker and Associates

(These Comments are not Transcribed Verbatim.)

E. LaBudde: There is a desperate need among users to define the media

environmental and life expectancy issues, to establish definitions and test methods,

and to avoid being locked into a specific implementation of a combined product and

design. There is a widespread need for OD^ media removability and reading disks on remote devices to achieve data interchange. The need for interchange affects the

file structure and data formats as weU as the mechanical and optical characteristics

of 0D3 systems and media.

D. Chen: There is latitude for various manufacturers to conform to a standard at

this stage of development.

M. Goldberg: A diversity in standards is needed to accommodate the range of disk

sizes and requirements needed for various applications. For instance, among the

low-end OD^ products, there may be a need for automated disk handling that

inherently has different requirements and applications as compared to automated

handling within high-end OD^ products.

Dr. Goldberg suggests the term "optical disk library (ODL)" be used in lieu of

"jukebox" to denote the modularity of automatic disk handling hardware.

Dr. Goldberg referred to video and digital audio disk technologies to acknowledge

that some standardization-related issues between these and optical disk

technologies may be similar. However, only those issues directly related to OD^

would be addressed in this workshop.

Floor: Should non-spinning media be considered in this standardization workshop?

These media were not included in the program as they were not considered to be

compatible with OD^ technology.

D. Morin: Development of processing systems for use in Department of Defense

(DOD) systems requires a very large investment in hardware very early in the

development cycle. Significant changes in the functional and/or interface

characteristics of any piece of hardware within the system at any point within a 5-year development cycle can significantly increase the development cost and

schedule. Standards help to reduce the risk of the use of a new piece of hardware

129
(e.g., optical disk) in a system (1) by guaranteeing that compatible hardware will be

available at all phases of the development cycle and (2) by stimulating the

development of multiple sources of that piece of hardware by the end of the

development cycle so that actual system production requirement can be met. The

lack of standards will discourage the use of an optical disk in DOD systems.

J. Davis: The publishing industry uses video disks, and thousands of replications of

these disks are anticipated. As an industry, they could not see standardizing any

aspect of 0D3 technology that would not facilitate data interchange.

D. Shoemaker: Manufacturers are starting to look increasingly toward standards

activities for guidance in product design. Therefore, there is a growing awareness

of a particular standard's value. Simultaneously, the standards process is being

accelerated and becoming more responsive to the groups that are writing standards.

Floor: The integration of OD^ devices and system upgrades relies on compatibility

achieved through software and hardware expertise. According to this OD^ systems

integrator, environmental standards for this OD^ application are even more valuable

to systems integration than hardware and software standards.

The lack of data interchange through media compatibility for office products (word

processors) is a situation which occurred due to the lack of data interchange

standards.

D. Shoemaker: Most of the speakers have emphasized the desire for compatiblity

and interchangeability of media.

E. LaBudde: Some users want anything they can get now while others would prefer

to wait for more product stability.

M. Hogan: Examples can be cited of the lack of economies in a particular market,

due to a lack of standards. The lack of standards could impact the growth of the

OD^ market.

130
2.1.12 0D3 Media Exhibit

Optical digital data disks were brought to the Workshop on Standardization Issues

for 0D3 Technology, by their developers. This collective effort was requested of

the workshop participants by the workshop program committee. The disk collection

was set up specifically to illustrate one of the key topics of the workshop—the

diversity of current disks, which was obvious in the various dimensions and disk

storage capacities.

The disk "display," assembled for technical information only, within the context of

the workshop, had disks ranging in size from 120 mm (4.7 in) outside diameter disk

with 15 mm (0.6 in) inside diameter to a 356 mm (14 in) outside diameter disk with

168 mm (6.6 in) inside diameter. These same disks, which were the smallest and

largest disk, considering physical dimensions, had a storage capacity of 150 x 10^

bytes and 4 x 10^ bytes, respectively.

Following is a description of the optical digital data disk, from the Library of

Congress "Demand System," that was exhibited by a representative from the Library

of Congress.

362 mm (14.25 in) disk

168 mm (6.6 in) inside diameter

Data Encoding Method is Modified MFM - Single Sided

Raw formatted capacity = 4.866 GBytes

User Data Capacity = 3.8 GBytes

Recording Surface is 300 Angstrom Layer of Tellurium Alloy

Substrate is Optical Glass 1mm Thick

Hole size = .4 micron. Hole Spacing = .8 micron. Track Spacing = 1.1 micron

Total Tracks = 49,500, Sectors per Trace = 192, 512 bytes/sector

131
2.2 SESSION n PRESENTATIONS AND DISCUSSIONS - LEGAL

AND ARCHIVAL REQUIREMENTS OF AN OPTICAL MEDIA UNIT

2.2.1 0D3 system CONSIDERATIONS OF

BUSINESS ARCHIVAL INFORMATION

By Morris Cohen

NCR Corporation

Key words: audit; business record; time insensitive schema.

Introduction

Mr. Cohen emphasized the importance of business record keeping methodologies

which support auditors. Business archival documents must be reliable, meaning that

they should be protected from alteration. There should be a means for identifying

when a record was written and a mark of its authentication identification. There

should be protection against automated forgery; e.g., electronically building a

falsified image from pieces of valid images. The collusion factor should be

minimized. The worst case is where a single individual can perpetrate a crime; i.e.,

the more people who have to collaborate, the harder it will be to achieve successful

collusion. The potential use of OD^ technology for "permanent" data storage of

business-related information has many advantages, including eliminating the "check

written-in-pencil" syndrome.

Record Survivability

Survivability is essential for business records. Ten years is not a magical number;

for some records, useful life may be 7 years, for others, 25 or more. The period for

which records need to be updatable, need not be as long. Stored information should

be insensitive to the following:

(1) Time

(2) Use

(3) Unforeseeable missions

(4) Broken equipment

(5) Abuse

(6) Theft

(7) Breakage of media

(8) Misplacement

Information Recovery

Recoverability of business information is important. There should be on-board

schema to aid in locating, identifying, and interpreting information, as well as on-board encoding algorithms, in machine-independent form. Consideration must be

given to the maintenance of defined terms needed to find and understand the data.

A balance must be achieved between long-term understandability and long-term

security.

132
Conclusion

The necessary requirements for the secure computer storage of business information can all be met if there is a method of achieving multiple certifiably-true, read-only

copies, with on-board schema and algorithm information all properly distributed and

protected. The existence of multiple copies of the information in different

locations provides protection against a perpetrator who may be able to alter a

particular copy, but does not have access to all of the copies. A malicious act can

be circumvented by comparing the false and true copies.

133
2.2.2 A PARTIAL SOLUTION TO THE

DATA INTEGRITY PROBLEM

By Dennis Branstad

National Bureau of Standards (NBS)

Key words: authentication; cryptography; data integrity; data protection; secrecy;

security.

Introduction

The advent of new technologies in data processing result in new questions being

raised, as well as the old. The development of new data storage technologies, such

as Optical Digital Data Disk (OD^), have again raised the question, "Will the

integrity of the data be assured?"

0D3 can replace many forms of storage media that are used for long-term retention

of records. Integrity assurance means that recorded data can be read correctly and

that there has been no accidental or unauthorized modification of the data while

they were stored. Additional security requirements for vital records often include

both the secrecy of the data and the ability to verify the authenticity of the

originator of the data. Since many documents can be stored on a single disk, it may

be necessary to control access to the data on such a shared storage medium.

Integrity Problems and Solutions

The Od3 storage media are subject to several potential data integrity problems.

Writing errors and reading errors can be detected with conventional

"read-after-write" or "read while write" methods. Media degradation and

read/write alignment requirements must also be evaluated before OD^ can replace

the alternative media for long-term data retention. Backup copies should be made

for all vital data and these should be stored separately, however, the backup may or may not be recorded on Od3 media. Potential media degradation under various

physical environments must be evaluated before a backup media is chosen.

Intentional, undetected modification of data is the part of the integrity problem

discussed in this presentation. A solution to this problem also results in a solution to

the problem of detecting accidental modification, but not vice versa. A slight

modification of the solution also solves the problems of unauthorized access to data

and unauthorized disclosure of data.

Authenticating Stored Data

Authenticating stored data is a process which verifies that the data has not been

modified, either accidentally or intentionally, subsequent to storage. Various error detection codes may be used to detect any accidental modifications but

cryptographic-based error detection codes are generally necessary to detect

intentional, intelligent modifications of data. The term "generally" is used because

other methods can be used for certain media under certain circumstances. For

example, modified credentials such as driver's licenses can be detected optically if

134
high quality images are pre-printed on high quality paper, under the age or identifier

that was changed.

The Data Encryption Standard (DES) algorithm is a cryptographic algorithm that

may be used to protect the integrity, secrecy, or both, of data. The algorithm

computes a 64-bit code for a 64-bit data input, using a 64-bit key. The 64-bit data

input generally represents 8 characters of data. For secrecy purposes, the 64-bit

code is communicated or stored. The receiver or reader can transform the 64-bit

code back to the 64-bit original input, only if the original 64-bit key is used.

A cryptographic-based error detection code, now commonly called a Message

Authentication Code (MAC), can be easily computed with the DES algorithm on data

stored on 0D3 media (or any media). The data to be protected are divided into

8-character groups (terminated by zeros if necessary). The first group is encoded

with the DES. The result is added (modulo 2) to the second group. This result is then encoded with the DES. The result is added (modulo 2) to the third group. This

process continues until a final 64-bit result is obtained. The first 32 bits

(alternately, the entire 64-bits) of the result is called the MAC, which is then

appended to the data and stored on the media.

When the stored data is read, the same sequence of operations is performed on the

read data; i.e., another MAC is computed. The cryptographic key used to compute

the first MAC must be used to compute the second MAC. If the MAC computed on

the data before it was stored is identical to the MAC computed on the data after it was read, then it is concluded the data has not been modified, with a probability

equal to 2^2 (alternately 2^^*) MAC length. No one can change the data and change

the MAC to correspond with the modified data unless the key is known. A key

management system must therefore be used which stores the key until the data is read. The key must be protected from disclosure, destruction, and replacement.

If integrity protection and secrecy protection are desired, a MAC is similarly

computed and then the data and MAC are enciphered. NBS has proposed a standard

for performing these functions.

A good key management system will also provide access control to data on a shared

disk. Each user must supply a personal key which is used to unlock the stored key

which protects the data. Such a system thus authenticates the originators and users of the data.

Ckmclusicxis

The Od3 storage technology should make use of available integrity and security

technologies as they are developed. This presentation described one method which

can be used to provide a high degree of protection for OD^ technology, as well as other data storage technologies.

135
2.2.3 MEDIUM TERM, LONG TERM, AND ARCHIVAL

PROPERTIES OF PHOTOGRAPHIC MATERIALS

By Peter Adelstein

Eastman Kodak Company

Key words: American National Standards Institute (ANSI); archival; archival

photographic film; long term photographic film; medium term photographic film;

photographic film.

Introduction

The life expectancy of data recording materials is a property of increasing

importance to the consumer. The critical needs for long time keeping have been

reflected in an increasing number of publications on the keeping characteristics of

various materials, particularly photographic film and magnetic tape. Although

standards on the permanence of photographic film have existed for close to

40 years, the last decade has witnessed much greater activity in the specification of

storage conditions and of material permanence.

The need for research activity on life expectancy, and the consequent reflection in

national standards, is necessary to provide the user with the needed confidence in

the permanence of his media materials. This information is particularly important

for an emerging technology in which there is not a great deal of practical keeping

experience to draw from. The purpose of this paper is to describe the

standardization activity, in the photographic industry, on permanence and the

resulting definitions that have been agreed upon. It is expected that this background

may be of some use to those who must answer similar questions on optical disks.

American National Standards Institute

The American National Standards Institute (ANSI) is the recognized national

standardization body in this country. It publishes the standards and specifications

prepared by various national societies (such as the American Society of Testing and

Materials (ASTM), Technical Association of the Pulp and Paper Industry (TAPPI),

etc.) as ANSI documents. These are then recognized in international organizations

as standards from the United States.

Overall coordination of standards activity in image formation is implemented by the

Image Technology Standards Management Board (ITSMB). Their scope includes not

only conventional photography, but the audio visual field, graphic arts, and areas of

electronic imaging. The ITSMB has set up seven photographic (PH) committees (see

fig. 1), each responsible for a different area of interest. These committtees are sponsored by trade organizations or technical societies who provide the

administrative and secretarial functions. Storage and permanence is handled by

Committee PHI which is divided into various subcommittees and task groups to

work on specific assignments. The National Association of Photographic

Manufacturers is the sponsoring society.

136
Definitions

Before specifications can be written on photographic materials having various levels

of life expectancy, terms must be agreed to--which define these different levels.

This has proven to be one of the more difficult tasks in these standardizing efforts.

Fortunately, this assignment is now completed with three different levels of

permanence being defined.

(1) medium-term film is a photographic film which has a useful life in excess

of 10 years,

(2) long-term film is a photographic film which has a useful life in excess of

100 years, and

(3) archival film is a photographic film which is suitable for the preservation

of records having permanent value.

All three definitions recognize the concept that these films must be stored under

appropriate storage conditions to achieve the indicated life expectancy.

The most controversial of these definitions is the word "archival." This term has

been used and misused over the years, describing life expectancies varying from 10

to 500 years. Such practices have led to considerable confusion and

misunderstanding. Unfortunately the term "archival" has sometimes been employed

to promote a particular product rather than to impart information about its life

expectancy.

The word archival was first used in image technology standards to define the

preservation conditions for silver microfilm intended for "the maximum period

obtainable." Since silver images had over a century of excellent stability, this term

was subsequently incorporated by Committee PHI into the film specification for

black-and-white silver images^l). The committee recognized that maximum storage

life should not imply absolute permanence. Consequently, they define archival film as suitable for "records having permanent value." A specific time period was not

established.

This very demanding definition of archival materials was most recently reexamined

during deliberations on film specifications for medium and long-term film. A

definitive statement was requested by and received from the Archivist of the United

States(2). He stated that the term "archival" is synonymous with "permanent."

While being permanent cannot be guaranteed, it is important that any new archival

record film be equal to or better than current archival film as defined by ANSI^^^.

This viewpoint, representing the current thinking of U.S. Government agencies and

of ANSI, must be considered in the preparation of permanence standards in image

technology.

There is another aspect of photographic film standards which should be mentioned.

All film specifications on permanence apply only to copies which are storage copies

and are not work copies. The committee felt that work copies may become dirty,

scratched, or contaminated so that they may not exhibit the behavior expected from

the inherent properties of the film itself. This is a question which will have to be

addressed by the optical disk community. The answer may depend on the possible

disk damage that could occur during use.

137
Reference

American National Standards specifications for photographic film for archival

records, silver-gelatin type, on cellulose ester base, PHI. 28.

J. B. Rhoads, letter to P. Z. Adelstein, Journal of Applied Photographic

Engineering, vol 2, 2, p. 64A, spring 1976.

138
03 TJU

CO T3c

4-1 COo

pa >.00 4-1 o c

1—1o e c OJoc u CO

a; e H CO

0)oc

COeM e

-H

<4-i c o o

V-i •H u 4J •H CO 2 •HU0

CO cn c cn o <:

•H

4-1 CO Z

a.

u

•H

cx

COu

ODO

4-1 o

CO

)-l "4-1 0) o )-l 3 c 4-1 o u

•H CO iJ

CO 3

•H

C o to o

cn

en <:

r-HCOco

•H

4-1 to z

c^

"PC

P-i co

00 •H c 4-1 •H CO u N o T-l

Cfl c c CO o 00 a u

on o

X.ou

0)3o

•H

PuIcoos

COa

•H

(X

COu

00o

)-l u

CO3

CO>o

•rl T33<

00

•H

CO

CO

0)oo

04

to3

4.1 COu

COa

D-

<:

>>

S-1 4-1 0)So

4-1 •H

(0c

COa

•H

to

&4

CO t3M

COc

CO

to c

q; CO

4-1 Pu

CO Ou 4-1 o

to c/ou

i-i oc Ta o tu to T3o ^ p c

14-1 OJ CO Q ^ B

4-1 4-1

C CO O C CO •H -H Cd

4J I •H C

CO to

tvl 0) •HC -u

CO T-( 0) 00 > 4-1

1-1 -H CO O 4-1 1-H O 0) 3

00

•H

tl4

139
2.2.4 THE MEANING AND USE OF "ARCHIVAL"

By Thomas Brown

National Archives and Records Service (NARS)

Key words: archival; archival life.

Introduction

Two definitions or usages of the word "archival" are seemingly common. First, the

ADP community uses the term for "long-term" tertiary storage and in the process

has created a verb "to archive." But in most ADP environments, this "long-term" is really a very limited time. Indeed, some vendors promote products as "archival" if

it has a storage life of as little as five years. The professional archivist has a

different concept. As an example, the professional archivist glossary does not

include a verb "to archive."

Definition; Archival

"Archival" in the professional sense of the word is derived from ancient Greece and

stresses the concept of records created by an organization rather than individual.

Such organizational records are "archival" if they have permanent value, continuing

value, enduring or unending value. Simply put, "archival" means permanent or

forever. Given this difference in definitions, the professional archivist might argue

that his or her definition is the correct one because of its usage in Western

Civilization for two and half millenia (2500 years). A stronger position, however, is Federal law (44 U.S.C. 2103) which adopts the professional definition when it defines

archival records from Federal agencies as those which "have sufficient historical or other value to warrant their continued preservation by the United States

Government." Lest someone argue that this refers to only paper documents, 44

U.S.C. 3301 specifically includes machine-readable materials in the definitions of

records. This would mean optical digital data disks as well as magnetic media.

Obviously, not every record an organization creates has permanent or enduring

value. Indeed, only a small minority of the records would faU into this special

category. Who makes this determination? It is the archivist. Once the archivist

makes that decision, the determination does not make the media of the record of

archival quality. Rather for the media to have archival quality it must have the

same permanency as the information. If archival information is on a less than

permanent media, then the information must be transferred to another media of

archival quality or to another media of transitory quality until an archival quality

media is developed.

Attributes of Archival Quality Media

For a media to be certified as "archival," it must meet three tests. The first of

these tests is the media life. When the Archivist of the United States declared that

"archival" is synonymous with "permanent" and "forever," he admitted that it was a

"rather positive statement and which none of us can guarantee." As a practical

matter in certifying materials for permanent records use, they must have a media

140
life equal to or greater than the media with the longest, long-term keeping ability.

When film was certified as archival, it was determined through accelerated aging

tests that it was equal to or greater than high-quality rag paper, that experience

had shown to have a media life of at least 500-1000 years. Based on this precedent,

newer materials can be approved as archival if they are equal to or greater than the

present materials that have been certified for permanent record use. In making this

determination, the media should be evaluated in conditions resembling an archival

environment. Since the need to access materials declines over time, media will hold

information that is used infrequently. As a corollary to such infrequent use, speed

of access to records in archival custody is not significant. Also, an archives will

store the records in an environment to optimize the media life.

The second attribute of archival quality media is that the image should be

preferably unalterable. If it is alterable, it should have a built in audit trail. This is necessary to make an archival record a legal record. The last attribute is interchangeability, accessibility, or transportability. This is necessary because the

information must be able to be sent for deposit to an archives. And the archivist

must be able to allow researchers access to the information. Thus the media must

be independent of any software or hardware. This interchangeability is complicated

by the fact that future equipment must be able to access the media. Hence the

media must be transportable across time to future equipment, yet to be designed.

Conclusion

These attributes of archival quality are admittedly stringent, but necessary to the

true definition of the word. My impression of the present OD^ technology is that no

product presently meets these criteria. For these reasons, OD^ archival standards

should not be developed at the present time. Any standards in the future must not

associate "archival" with any time scale as this will only serve to muddle the

definition. Hopefully, technology will advance and develop a storage technique

which will meet the professional and strict definition of archival.

141
2»2.5 WHAT CONSTITUTES A LEGAL DOCUMENT?

By Thomas 6a^

National Bureau of Steindards (NBS)

Key words: copies; evidence; legal documents; legality; microforms; optical media.

Introduction

The legality of optical media, or any other record media, is based on the acceptance

of the information on the media as admissible evidence in a court of law.

For a record to be accepted, it must be admitted to the court's proceedings. This

requires the permission of the judge and it is helpful if both sides agree; if not, the

judge decides.

In general, records can be considered under the "best evidence rule" or the "hearsay

rule." Different jurisdictions treat each rule and their exceptions in various ways,

be they originals or copies. There are a number of precedents for accepting various

types of records but none cover more than one type. The verification of

authenticity is essential to any record being admitted as evidence.

Human Readable Legal Documents

Several commissions have been formed to draft procedures that would establish

conditions under which microfilmed records could, in general, be accepted as legal

evidence. One commission proposed the "Uniform Photographic Copies of Business

and Public Records as Evidence Act." Another developed the "Federal Rules of

Evidence" for Federal Courts. These two sets of rules differ slightly and most

states have adopted them in whole, or in part and consider the record as evidence

without distinguishing whether it be original, facsimile, or a reduction copy. (The

details of the form and media are subject to definition by the various jurisdictions

and type of proceedings.)

Microfilming "in the normal course of business" is an important criterion which is supported strongly if records management procedures for microfilming are documented, including quality control and inspection procedures, and are rigorously

followed. When microfilming, it is helpful to have a certificate giving the date

filmed, the authorizing person, and the name of the camera operator recorded on

the same roll of film.

Conclusion

To improve the chances for a human-readable record to be accepted as legal

evidence, it must be made according to the following minimum requirements:

(1) The original record must have been made in the ordinary course of

business. If a facsimile, the copy must be made in the ordinary course of

business - particularly when the records retention schedule permits that

the original record may be destroyed or distributed such as checks, sales

142
slips, etc. (Computer generated microforms have been considered as an

original and sometimes as a copy.)

(2) If copies are made, the process used must accurately reproduce the original on a durable media. For this purpose, a durable media appears to have

several connotations. One, it must have a life expectancy of at least as long as the evidence (information) could be legally required; i.e., as long as the statute of limitations. Another, it must be possible to detect if the

record has been altered. This is a means to reduce or detect fraud.

(3) The record must be identified and authenticated to be a true copy of the

original.

References

(1) G. Walters, "The Optical Data Disk and the Office Information System,"

Association for Information and Image Management, Silver Spring, Maryland,

publication no. D008.

(2) J. R. White, "Practical Preservation of Information," Association for

Information and Image Management, Silver Spring, Maryland, publication

no. D009.

(3) R. E. Williams, "Legality of Microfilm," Cohasset Associates, Inc., North Lake

Shore Drive, Chicago, Illinois, 1980.

2.2.6 Panel Discussion: "What is the distinction between

legal and archival requirements for any document;

how could OD^ be used in an application that requires

both a legal and archival storage medium; how could

archivability be viewed with respect to a new technology?"

L. Fujitani, of Optimem summarized the discussion following presentations of legal

and archival requirements of an optical media unit, with the observation that

microfilm can be read visually, whereas OD^ requires a system to be read. The

typical manufacturing lifetime of data processing products is 5 years; this means a

useful life of 15 to 20 years, after which the product obsolesces. Therefore, when

defining and specifying the life expectancy of OD^ media, it is important to keep in

perspective, its hardware requirements and their built-in life expectancy. Both

aspects must be reasonably quantified, in relation to each other. There appears to

be a major discrepancy between archivists and the OD^ technologists regarding

archival life.

143
2.3 SESSION m PRESENTATIONS AND DISCUSSIONS - TEST METHODS FOR DETERMINING

RELATIVE MEDIA & DATA LIFE

2.3.1 UNRECORDED MEDIA - SHELF LIFE

By Martin Levene

RCA

Key words: accelerated aging test; activation energy; Arrhenius equation; relative

humidity; shelf life; temperature; unrecorded media.

Mr. Levene explained that "unrecorded" in the context of this presentation referred

to media having no user-recorded data. He stated that the typical shelf life

requirement for unrecorded media was 4 years, while the post recording requirement

(expectation) was 10 years.

There is presently little supporting material available for projecting media shelf

life. Accelerated aging test procedures are needed. The Arrhenius relation is one

that has been used, since it gives some insight into the effect of prolonged elevated

temperature on aging. (Reference: "Accelerated Versus Real Time Aging Tests," E.

W. Kimball, 1980 Proceedings Annual Reliability and Maintainability Symposium.)

The Arrhenius equation, based on time and temperature, is expressed as follows:

where D is the test duration in days,

L is the life equivalent in days,

E is the activation energy (ev),

R is Boltzmann's constant 8.63 x 10"^, ev/deg.,

Tn is the normal temperature (2980K),

T^ is the accelerated aging temperature in degrees K.

Note: In OD^ accelerated aging tests, high temperature is the principal

environment factor while high humidity is a second factor.

The activation energy is the energy required to move an element out of a metastable state and into a stable state. The use of the Arrhenius relation assumes

that there are no discontinuities in the behavior of the test specimen over the range

of interest.

F^. 1 presents a plot, based upon the above Arrhenius equation, which can be used

to predict the test duration needed to simulate a 10 -year life for several test

temperatures. The dashed line example in fig, 1 shows that for activation energy (E)

Introduction

Accelerated Aging Tests

D = L

e

144
of 0.36 ev and accelerated test temperature (T^) of lOO^C, the test duration should

be 220 days in order to project a 10-year lifetime. This approach can be of value to a vendor's quality assurance operation, once the appropriate values of E and are known.

F^. 2 shows a replotting of the same Arrhenius equation, but this time graphed for a

specific activation energy (again E = 0.36 ev as the example). With this plot, some

further insight may be gleaned if the disk fails before 220 days. A failure after 100

days at lOOoC, for example, would predict a 4-year life.

Humidity is another important factor in the aging process. If, however, the aging

process can be shown to be relatively unaffected by variations in humidity, then the

humidity level selected for accelerated testing can be chosen on the basis of

convenience. Otherwise, it becomes necessary to determine the effects of humidity

and then choose a test level in relation to the anticipated storage conditions. Fig. 3

shows the expected Life vs. Temperature and Life vs. Relative Humidity (RH)

curves for the situation wherein temperature is dominant and the variation of

relative humidity is of relatively low significance.

Conclusion

Important questions to be resolved relative to aging tests include the following:

(1) What are the appropriate activiation energy values for the candidate

materials?

(2) Is oxidation or corrosion or another process (u-v exposure?) the important

one?

(3) If both temperature and humidity variation is significant, how do we

evaluate the data?

(4) Can a good correlation be established between accelerated aging test

results and normal environment experience?

145
.1 .3 .5 .7 .9 1.1 1.3

Activation Energy (eV)

. Given activation energy and test temperature line

. Find duration of test before failure to predict ten year life

Figure 1, Optical Disk Testing Test Temperature and

Duration vs. Activation Energy

(Levene - RCA)

146
J

TEMPERATURE (DEG C)

. GIVEN TEMPERATURE OF TEST E = . 36

AND DURATION OF TEST TO FAILURE AGING

. FIND LIFE PREDICTION

Figure 2. Optical Disk Testing - Life Prediction

(Levene - RCA)

147
PROCEDURE FOR ONE POSSIBLE CONDITION, WHEREIN:

TEMPERATURE IS DOMINANT INFLUENCE

RH VARIATION IS OF LOW SIGNIFICANCE

LIFE

(YRS)

LIFE

(YRS)

RH1

RH

2 RH

3

TEMP.

THEN, FOR A GIVEN MATERIAL:

. SELECT FAILURE CRITERION

. SELECT CONVENIENT RELATIVE HUMIDITY (RH)

. PLOT PREDICTED LIFE VS. TEMPERATURE

. COMPARE NORMAL DETERIORATION RATE (LONG TERM

TESTING) WITH ACCELERATED AGING TEST RESULTS

Figure 3. Optical Disk Testing - Humidity Included

but Temperature Effect Dominant

(Levene - RCA)

148
2.3.2 RECORDED MEDIA - DATA LIFE

By Louis Spruijt

Optical Media Laboratories (OML)

Key words: accelerated life test; corrosion of tellurium alloy; data life/error

growth; degradation mechanisms; disk construction life; disk-drive interface

(degradation of functional parameters); temperature/humidity test.

Introduction

Louis Spruijt emphasized the importance of understanding the degradation

mechanism of GD^ recorded media. Degradation is not limited to only the 0D3

media construction. It can occur at other points in the system, such as the

disk/drive interface or at data level of the disk/drive/system.

Degradation Testing

Mr. Spruijt described advantages of using glass for protecting the 0D3 media's

sensitive layer. Glass is known to be very stable, impervious to contaminants, and

quite scratch resistant. It can be processed to achieve a ten-fold improvement in its

ability to resist breakage. The glass substrate used in the GML disk is treated to

increase its resistance to breakage.

A standard l.E.C. temperature/humidity test for degradation of media life involves

daily cycle for a prolonged period. In this testing the effect of water and oxygen on

the tellurium alloy is the increase of the transmittance, thereby lowering the

reflectivity and reducing the signal. The choice of composition for the alloy is important for stability against corrosion. Also, the accelerated test shows changes

on tracking and synchronization drive/disk system margins. Gn data level, an error

analysis is helpful to determine the degradation mechanisms of the data integrity.

A comparison between original data and life tested data errors on media identified

by their exact location is used.

Conclusion

Disk life can be tested using an accelerated life test. Life of the data written or the usability of empty tracks depends on different mechanisms; e.g., life of the

hermeticity of the disk, life of the reflectivity within the system margin or growth

in number and/or size of defects. Special testing conditions are necessary for open

and closed disks. Acceleration factors for the different degradation mechanisms for

the test can be estimated. For GML disks, the corrosion of the tellurium layer and

the growth of the number of micro-sized errors showed to be (relatively) the

important factors for degradation, occurring only after the moment the hermeticity

of the disk is broken introducing condensation of water onto the disk recording

surface during test conditions. (See figs. 1-12, table 1, and figs. 13-14.)

149
AGING OF OPTICAL MEDIA

DEGRADATION MECHANISM OF MEDIA

ACCELERATED AGING TESTS

Figure Factors to Determine for Estimating

the Expected Life of Media

(Spruijt - Optical Media Laboratories)

DEGRADATION CAN OCCUR ON DIFFERENT LEVELS

DISK CONSTRUCTION

. MECHANICAL

. OPTICAL,

. HERMETICITY

DISK - DRIVE INTERFACE

. FOCUSSING

. TRACKING

. SYNCHRONIZATION

DATA

. READ RELIABILITY

. WRITE RELIABILITY

Figure 2. Degradation Levels

(Spruijt - Optical Media Laboratories)

150
DISK CONSTRUCTION

MECHANICAL

- VIBRATION TESTS

- SHOCK MECHANICAL

- IMPACT TEST

- DROP TEST

OPTICAL

- SCRATCH TEST

- DUST TEST

HERMETIC ITY

- SHEER TEST

- THERMAL SHOCK TEST

- PRESSURE TEST

- HUMID ITY /TEMPERATURE TEST

Figure 3. Degradation Mechanisms and Tests

(Spruijt - Optical Media Laboratories)

DISK - DRIVE INTERFACE

FOCUSSING - HUMIDITY/TEMPERATURE TEST

. BLISTERING OF SENSITIVE LAYER

. WARPING OF SANDWICH

. CORROSION OF SENSITIVE LAYER

TRACKING/ SYNCHRONI ZATION

. CORROSION OF SENSITIVE LAYER

o SWELLING OF SUBBING LAYER

Figure 4. Degradation Mechanisms and Tests

(Spruijt - Optical Media Laboratories)

151
DATA

READING:

- GROWTH OF DEFECTS

- GROWTH OF NOISE LEVEL

- REDUCTION OF SIGNAL TO NOISE RATIO

WRITING:

- CHANGE OF HOLE OPENING PROCESS

- CHANGE OF THE FOCUS QUALITY DUE TO DISK DEGRADATION

Figure 5. Degradation Mechanisms and Tests

(Spruijt - Optical Media Laboratories)

152
Figure 6. Z/AD Temperature and Humidity

I. E.G. Test (Z/AD) Daily Cycle

(Spruijt - Optical Media Laboratories)

153
oCOO<

COo c

-H

O

M -H < -Uu

•H

i-i ou

-a tu o

TO CO

0)O

HCo

•H

CO

W o cO 13

cn. S

to jj OHO U C I o • 4-1

4-1 •!—I

0) CO 3 3 E a

00

M !yo oCN

154
Figure 8, Corrosion of Te and Te Alloys,

Impact on Transmission and Reflection

(Spruijt - Optical Media Laboratories)

10 20

days Z/AD

155
writ©

DATA

"i original

DATA

life test

read

DISK

]

RECORDER

COMPARE

FILE

DATA

ERRORS

SERVO

ERRORS

RAD lUS

& ANGLE

ANALVSIS

system + disk

technology

Figure 9. Analysis Setup of Error Growth in Number or Size

(Spruijt - Optical Media Laboratories)

156
(0O >^

Q)Q ^ (/} CO

rt c <u

1-1

H 1-1

a o c - J~>

<u -H o a XI

CO 0 J

•H

CO

QJ -H E T3

(-< CJ 1 iH C CO o o 5o

pa

CO cu O (U O H 4J o- cn I H H

•r-) • u-j D O -H )-i -H J a

OOuM oo

00

00

inO oHH

COM

Oooo

(N

ATE:

K: 0

c»

<y>

H <r

w

t-i

H

H

W

<t!

i-i PQ o1 w

CO

CM•

CO

PiOwOH

CJW

157
CO

CO Q -

4J

)-l •HXiH

Piouw

•H

CO

OJ •Huo

0)o

CO •H

TJ

(U s

COa

•H

+j o

iH XI

CO <U O 4J •H CO >. H H

(U

•H

IW CO •H

01

to

•H

Wo O

CM

00

00moCVJ

H

CO

K: o 00 oo H <r o rH

eg

.ST CM • •

CO

Pi

m o o1 O w w

CO

w • oH H CJ M M

pq CO

158
ACCELERATED LIFE TEST

BER versus ANGLE

2,jS BITS/SAMPLE

10

=30 DAVS

liiiiuii =60 DAVS

1=1 =90 DAVS

Figure 12. Typical Bit Error Rate Increase of

a Z/AD Life Tested, Non-Hermetic Disk

(Spruijt - Optical Media Laboratories)

159
TIME IN HOURS 1 700

BER X 10

^ 5.0 35»0

TRANSMISSION % 13.2 15.2

PNR IN dB 47 42

SNR IN dB

56 53 (WRITTEN HOUR 1)

SNR IN dB

(WRITTEN HOUR 700)

SENSITIVITY IN nj 0.40 0.45

Table 1. Typical Degradation of Functional

Parameters of Non-Hermetic Disks

in Accelerated Test After 700 h. Test

(Spruijt - Optical Media Laboratories)

160
DISK

STORAGE

CONDITION

T

<«C)

RH

y.

ACC.

FACTOR

S INGLE OFFICE 25 50 5

SANDM

.

OFFICE 25 50 <<1 (?)

8ANDM.

CLOSED

ZA/D 25-65 93+3 1 (?)

8ANDM.

OPEN

OFFICE 25 50 4 - 10

SINGLE ZA/D 25-65 93l3 50 - 100

SANDH.

OPEN

ZA/D 25-65 93i3 200 - 1000

Figure 13, Acceleration Factors for Different Disk

Constructions Compared with Office Condition

(Spruijt - Optical Media Laboratories)

161
2.3.3 TEST METHODS FOR MEASURING LIFE

EXPECTANCY OF PHOTOGRAPHIC MATERIALS

• ' ^ ^ V By Peter Adelstein

Eastman Kodak Company

Key words: American National Standards Institute (ANSI); Arrhenius relationhip;

permanence, predicting useful life; optical density; photographic materials.

Introduction

Defining the useful life of a material is only the first step in the preparation of a

specification. Much more difficult is establishing the useful life and in

standardizing test conditions which can predict it. The past decade has witnessed a

considerable number of studies on photographic materials with these objectives.

Most of these followed a very similar approach. A study of diazo film can illustrate

the method that was used^D.

Arrhenius Approach Applicable

A number of diazo films were stored in the dark for periods up to three years at a

series of elevated temperatures and at a constant moisture level. Photographic

density was determined as a function of keeping time. See f^. 1, which illustrates

the typical density increase of a low density area at a series of temperatures.

Similar curves were obtained for other films, as well as for other measurements of

image change (such as density decrease of a high density area).

In addition to determining the temperature dependence of the images, it was

necessary to specify the maximum density change which could be tolerated without

affecting the usefulness of the film. The concept of usability is difficult to

quantify, but definitive density changes must be agreed to before a specification can

be written. This was done for the diazo films by examining different diazo images

which were specially prepared with a wide range of density values. Two criteria of

density change were agreed to, one specifying the maximum tolerable density in the

Dmin (minimum density) areas, and the second specifying the minimum difference

between the low and high density areas. These density criteria were then used to

analyze the density-time plots such as shown in f^. 1.

At each temperature, the time was determined at which the useful life was

exceeded. In other words, the high temperature incubation studies were able to

yield useful lifetimes at a series of elevated temperatures. The next step was to

extrapolate the useful lifetime to room temperatures. This was accomplished using

the classical chemical kinetics approach of Arrhenius^^), He had determined that

there is a linear relationship between the log of the rate of a chemical reaction and

the reciprocal of the absolute temperature. In the diazo study, a linear relationship

was obtained when the log of the useful lifetime (which is inversely proportional to

rate) was used. Typical graphs are shown in f^. 2 from which the useful life at

21^0 was determined by extrapolation.

162
It is recognized that the Arrhenius plot is intended to apply to simple chemical

reactions. However, it is being used for rather complex behavior featuring both the

reactions of various diazonium compounds and their light absorbing properties. For

this reason, it can be considered as an empirical treatment of the data. However,

this does not detract from the usefulness of this approach. As will be shown later, it is extremely difficult to prepare a meaningful permanence specification when the

Arrhenius approach breaks down.

The Arrhenius plots in fig. 2 for the three films are almost parallel. This indicates

that the temperature dependence of density change are fortunately very similar for

these films. This allows the construction of an Arrhenius graph which can establish

appropriate incubation conditions for a dizao stability test. Fig. 3 shows Arrhenius

plots, drawn with the same slope as found in fig. 2, through points for long-term and

medium-term keeping behavior at 210C. Incubation test conditions at TO^C and

80OC were established and incorporated into the ANSI specification.

The Arrhenius treatment of high temperature incubation results has proven to be

very useful for other products besides diazo films. Fig. 4 shows a similar graph for

the cyan dye fading of color motion-picture film(3). More extensive dye fading data

has been recently published(4), as illustrated in fig. 5, which gives the Arrhenius

relationship found for a color professional film at various density changes. This data

treatment has also been successfully applied to the density increase of a silver

image x-ray film (fig. 6) which was washed to different levels of retained

thiosulfate^^\

Besides its application for changes in the photographic image, Arrhenius plots have

been used to follow physical changes of photographic products. Fig. 7 shows the

rate in surface brightness decrease of photographic paper plotted against the

reciprocal of absolute temperature^^). The rate of fold decrease of photographic

paper^*^) is given in fig. 8 and the tensile strength loss of photographic film^^^ in

fig. 9. These physical changes are equally as important as the image changes in

determining the useful life of a material.

Arrhenius Approach not Applicable

It has been demonstrated that when the rate of image or physical change follows the

Arrhenius relationship, high temperature results can be used to predict room

temperature behavior. While this involves a great deal of laboratory work and is a very extended and extensive study, the approach is quite straightforward. However,

when the Arrhenius relationship does not apply, prediction of room temperature

behavior becomes an extremely difficult technical problem.

A good example of this type of behavior was experienced by a PHI task group who

were preparing an ANSI specification on the permanence of vesicular film.

Vesicular film is a light-sensitive photographic material in which the developed

image consists of many small bubbles, or vesicules, or nitrogen gas which are embedded in a polymer matrix. The vesicles scatter the incident light and create an opaque image when viewed by reflection. The stability of the image depends on the

preservation of the very small vesicles in the polymer matrix.

163
Unlike the image changes observed with diazo and color films at elevated

temperatures which are the result of chemical reactions, image changes with

vesicular film are due to a physical change. At high temperatures, the polymer

matrix softens, the vesicles collapse and the image disappears. The fallacy in

applying the Arrhenius treatment to predict long-term room temperature behavior

is that the polymer softening which occurs at high temperatures is not a good

reflection of room temperature behavior(9>10). jhis is illustrated by the Arrhenius

plots(9) in f^. 10. The solid lines represent the time for a 10% loss in the high

optical density area and there is a discontinuity at a temperature of 630C. This

temperature represents the softening temperature or glass transition temperature of

the polymer binder. Extrapolation of the high temperature data would predict a

useful life which is considerably less than extrapolation of the low temperature

data. However, the latter extrapolation is not practical to use to evaluate films

because of the long incubation times required.

The discontinuity in polymer behavior with temperature is shown by the dashed lines

in fig. 10. These plots were obtained by measuring the penetration of a weighted

probe into the thickness of the image layer. The change in slope of the Arrhenius

relationship also occurred at the glass transition temperature of the polymer binder.

This was additional evidence that flow properties of the binder at high temperature

cannot be used to predict those at more moderate conditions.

The problem in predicting the useful life of vesicular film can be simply stated.

High temperature data cannot be interpreted and moderate temperature data show

image changes which are much too small to use for extrapolation. The latter

behavior may give strong support (depending on the glass transition temperature) to

the viewpoint that image stability should not be a significant problem if the film is stored below the glass transition temperature. However, it does not give comfort to

the user who would like an accelerated test with which to evaluate the product.

The ANSI task group worked on this problem for a number of years and finally

resolved it by taking a very empirical approach. They agreed to standardize a test

procedure which involved a relatively long time at an incubation temperature

slightly below the glass transition temperature. The criteria for passing was an

optical density change just above the noise level of the densitometer. This rather severe test, coupled with 20 years of practical keeping experience, should give the user confidence that such films will have a useful life of at least 100 years.

However, the physical behavior of vesicular films as a function of temperature

precludes the use of a scientific method of useful life extrapolation.

Conclusion

Standardizing the permanence of materials in the image technology field has been

an ongoing activity for over four decades. This has resulted in the publication and

dissemination of information which has increased manufacturers' awareness of

product requirements and consumers' awareness of product performance. In addition, a technical approach has been established which can determine the useful

life of materials which show a continuous property change with temperature. It is expected that this experience can be of benefit to those in the optical disk field who

are concerned with establishing the permanence of these media.

164
o

o o

165
Figure 2. Arrhenius Plots for Printing Density Change of Diazo Film

(Adelstein - Eastman Kodak Company)

100,000

10.000-

1,000

o

E

.0025 .0030

Temperature Y°K

0035

166
Figure 3. Arrhenius Plots to Establish Incubation

Conditions for Image Stability Test of Diazo Films

(Adelstein - Eastman Kodak Company)

100,000

10.000-

o

"O

E

1,000-

100-

10

I 1

Reciprocal Slope =.00020

-100 ± «>K per decade time

in days

1

. Long Term Film

A (100 years)

t/> w //

-10 ^ /

g

i Medium Term

A Film

C /

P / /

-1 / /

/ j (10 years)

1 —

80 70

1 1 —21 °C

1— 1 .0025 .0030

Temperature ''K

167

.0035
o o ooooooo

Jo *9jn|Djaduj8| 96DJ0iS

I I

I I I i i a I L_J

1^ CD lo 5}- ro cvi — o a> 00 N

ro lo ro ro ro ro fo ro cvi cvi cvi S99J69P U!A|9>|

0001

168
m

toc

•H

60

•Ho

o

tHO

U

o c

0) a

CO 6

ca o V u

Q) COq

•H C

CO CO c e

•O CO

CO (U M

>s

£ c

CO -H >% 0) O u

CO -H O (U < 00 V

o

iH

c

a; us<

0)3

00

•H

(snis|93) ajnpjaduuai buipoj

169

10-2

o

ffi

10-'-

10-4 .

10-5

• ROLL E

X ROLL G

^ \

\ \

\ \

\ \

\ \

\ \

\ \

\

\

\ \

\ \.

\

\

90 70 50

TEMPERATURE, • C

30

2.8 30 32

l/^K X 10-*

3.4

Figure 7. Arrhenius Plots for Surface Brightness Decrease of Photographic Paper

(Adelstein - Eastman Kodak Company)

171
Figure 8. Arrhenius Plot for Folding Endurance Decrease of Photographic Paper

(Adelstein - Eastman Kodak Company)

Folding Endurance

100 80 60 40 20

Temperature,°C

2.6 2.8 3.0 3.2 3.4

1/°Kx10

172
Figure 9. Arrhenlus Plots for Tensile Strength Decrease of Photographic Film

(Adelstein - Eastman Kodak Company)

10*

10»

10*

«

>s

09 •oM

ino

c

0) U)V

M

c9

»-

10'

10'

10

1 I n~i r

1000

Cellulose

Triacetate Base Film

/ A

Polyester

Base Film

Temperature °C

100 90 BO 70

I I I I

21 J_L

.0025 .0030 .0035

173
Figure 10. Arrhenius Plots for Density Change and Thickness Penetration of Vesicular

Films

(Adel stein - Eastman Kodak Company)

10000

(h-''K)1000
References

P. Z. Adelstein and J. L. McCrea, "Dark Image Stability of Diazo Films,"

Journal of Applied Photographic P^ngineering, vol 2, 3, p. 173-178, summer

1977.

S. Arrhenius, "Uber die Reaktionsgeschwindigkeit bei der Inversion von Rohrzucker durch Fauren." Zeitschrift fuer physikalische Chemie, 4: 226-249,

1889.

P. Z. Adelstein, C. L. Graham and L. E. West, "Preservation of Motion-Picture

Color Films Having Permanent Value," Journal of the Society of Motion

Picture and Television Engineers, 79, p. 1011-1018, November 1970.

C. C. Bard, G. W. Larson, H. Hammond and C. Packard, "Predicting

Long-Term Dark Storage Dye Stability Characteristics of Color Photographic

Product from Short-Term Tests," Journal of Applied Photographic

Engineering, vol 6, 2, p. 42-45, April 1980.

D. F. Kopperl, G. W. Larson, B. A. Hutchins and C. C. Bard, "A Method to

Predict the Effect of Residual Thiosulfate Content in the Long Term Image

Stability Characteristics of Radiographic Films," Journal of Applied

Photographic Engineering, vol 8, 2, p. 83-89, April 1982.

G. G. Gray, "Determination and Significance of Activation Energy in

Permanence Tests," Advances in Chemistry Series, No 164, Preservation of

Paper and Textiles of Historic and Artistic Value, American Chemical Society,

p. 286-312, 1977.

T. F. Parsons, G. C. Gray and I. H. Crawford, "To RC or Not to RC," Journal

of Applied Photographic Engineering, vol 5, 2, p. 110-117, spring 1979.

P. Z. Adelstein and J. L. McCrea, "Stability of Processed Polyester Base

Photographic Films," Journal of Applied Photogrpahic Engineering, vol 7, 6, p. 160-167, December 1981.

A. T. Ram, "Vesicular Technology-In Perspective," Journal of Applied

Photographic Engineering, vol 8, 5, p. 204-209, October 1982.

O. J. Cope, "Diazo and Vesicular Microfilm Technologies," Journal of Applied

Photographic Engineering, vol 8, 5, p. 190-199, October 1982.

175
2.3.4 MEASUREMENT TECHNIQUES AND STANDARDS:

THIN FILM TECHNOLOGY

By Jane Clover

Optical Coating Laboratory, Inc. (OCLI)

Key words: characterization; coatings; durability; environmental; testing.

Introduction

There are measurement techniques and standards currently being used in thin film

technology that can be adapted to optical data disk technology. These include the

following:

(1) Environmental durability tests are well documented and may be used to

predict archival life if proper acceleration factors can be established.

(2) Spectral properties of disks can be measured using standard techniques on commercially available equipment.

(3) Calibration standards for reflection can be established.

Mrs. Clover described the tests for coated optics as inclusive of physical factors

such as dimension and cosmetic, spectral factors such as reflectance, transmittance

and absorption, and environmental factors.

Standard environmental tests for coated optics were also described by Mrs. Clover

as inclusive of humidity, abrasion, adhesion, salt spray, solubility, solvent

immersion, and cleanability, and exposure to dust and fungus. These tests are summarized as follows.

Standard Environmental Tests Used to Characterize

Performance of Coated Optics

(1) Humidity

Steady State: 24 hours at 49° C, 95% relative humidity (RH)

Cycling: ten 24 hour cycles of from SQOC, 85% RH to 650C, 95% RH

within 2 hours, hold for 6 hours and cycle back to 30° C, 85%

RH within 16 hours.

(2) Abrasion

Severe: 40 strokes with eraser at 2-2 1/2 pounds force in special

apparatus

Moderate: 50 strokes with cheesecloth pad at 1+ pound force in special

apparatus

176
(3) Adhesion

Slow or fast removal of tape from surface coating.

(4) Salt Spray

24 or 48 hour exposure to 6% salt solution fog at 330C

(5) Solubility

Salt: 24 hour immersion in 4.4% salt solution

Water: 24 hour immersion in distilled water

(6) Solvent Immersion and Cleanability

(7) Special Qualification Tests (per Mil-Std-810C)

Dust: 24 hour exposure varying wind velocity, dust (fine sand)

concentration, and temperature

Fungus: 28 day exposure to various fungus spores

177
2.3.5 ACCELERATED LIFE TESTING - OPTICAL MEDIA

By Philip Scheinert

Burroughs Corporation

Key words: accelerated life testing; environmental specifications; media

performance characteristics.

Phil Scheinert of Burroughs spoke on accelerated life testing of optical media. He

also discussed environmental specifications which include: dry and wet bulb

temperatures, relative humidity, thermal shock, altitude, mechanical shock,

vibration, exposure to various gases (H2S, NH3, NOx, O3, SO2), and salt spray.

These specifications are typically cited for four conditions: shipping, operating,

conventional storage, and archival storage. (The optical media unit must retain all

performance specifications during the specified lifetime of the unit.) There are

three basic lifetime models: Arrhenius, power model, and Eyring model (from

quantum theory). Refer to fig. 1. Mr. Scheinert described the experimental setup

for testing performance under stress conditions and showed waveforms used in

measuring test patterns (see fig. 2). Test results based on several hundred hours of

testing were briefly summarized (see fig. 3).

178
LIFE

Figure 1, Media Accelerated Life

Testing and Data Analysis

(Scheinert - Burroughs)

FAILURE

MODES

;

MIXED

POPULATION

STATISTICAL

DISTRIBUTION

WEIBULL

LOG-NORMAL

GAMMA ETC

.

ACCELERATION

MODEL

POWER

ARRHENIUS

EYRING ETC

.

RELIABILITY

CONFIDENCE

LEVEL

NUMBER OF

SAMPLES

NUMBER OF

STRESS

LEVELS

TEST TYPES

PARAMETRIC/NON-PARAMETRIC

NON-CENSORED/CENSORED

SUDDEN DEATH

SUCCESS-RUN

BAYESIAN

SEQUENTIAL ETC.

TESTING

179
Figure 2, Testing

(Scheinerc - Burroughs)

CONTROLLER SCOPE

DRIVE

MEDIA

DIGITIZER COMPUTER

EXPERIMENTAL SET-UP

PARAMETERS CURRENTLY MEASURED:

HIGH FREQUENCY S/N, PEAKS

BASELINE

NOISE

LOW FREQUENCY S/N

BASELINE REFLECTIVITY

HIGH

frequency

Ar

z

LOW

frequency

Ar

HIGH FREQUENCY S/N, TROUGHS

ANALOG WAVEFORM OF TEST PATTERN

Atro ADDITIONALLY: UNWRITTEN DEFECTS

WRITE DEFECTS (DATA WRITTEN INCORRECTLY:

CAUSES RELOCATES)

READ DEFECTS (NOT DETECTED AT TIME OF

WRITING, BUT APPEAR LATER)

180
Figure 3. Results

(Scheinert - Burroughs)

Tests at 45°C, 75% relative humidity show little

change In performance characteristics and no increase in errors for 900 hours.

To quickly characterize media aging characteristics

initial testing involved severe temperature

overstress. This also aids in the calibration of

proper observation intervals for "normal"

accelerated tests.

Unprotected (unovercoated) disks were exposed to

100°C and 135°C at ambient humidity.
2.3.6 SUMMARY OF MEDIA LIFE

By Tomio Yoshida

Matsushita

The media life of a write once optical digital data disk depends on the life of the

recording media itself and also has a close and strong relationship with the disk

substrate material and construction. From a user's point of view, the total stability

and reliability of the media including both the recording media and the disk

construction are important. The following fundamental characteristics of the

recording media are to be constant under a specified operating environment after

long term usage.

(1) Write Sensitivity

(a) The recording power to obtain minimum C/N ratio

(b) Threshold recording power

(c) Gamma characteristics

(2) C/N Ratio

(a) C/N ratio vs. recording power

(b) Maximum C/N ratio

(3) Second Harmonics

(a) Second harmonics vs. recording power

(b) Minimum second harmonics

(4) Reflectivity

The write sensitivity, C/N ratio, and reflectivity items are important for the design

of the optical drive, while the second harmonics are important to obtain high

packing density.

In this presentation, the properties which must be satisfied by the recording media,

test items, and test routine wiU be reported.

182
Initial test

No

Destructive test

Yes

Sensitivity

C/N ratio

Second harmonics

Play Back amplitude

Yes Mechanical constant

Drop out

Format inspection

Reflectivity

C

Change environmental conditions

Acceleration

Heat cycle

Humidity cycle

Low temperature

1^ Defect or life

^ Defect or life

Figure 1, Test Routine of the Media

(Yoshida - Matsushita)

183
2.3.7 Panel Discussion: "What test methods could be used

for the measurement of media life? Is there a possibility

of a standard test and if so, what should it be?"

Panel Participants:

Peter Adelstein, Eastmem Kodak Company

Ted Albert, U.S. Geological Survey

John Bray, NCR

Miguel Capote, Optical Coating Laboratory, Inc. (Moderator)

Mike Deese, Storage Technology Corporation

Charles Dollar, U.S. National Archives

John Dove, U.S. Air Force

Mark Goldberg, National Security Agency

Kent Hughes, U.S. Patent Office

Edward LaBudde, LaBudde Engineering Corporation

Pat Savage, Shell Development Company

Peter Sparks, U.S. Library of Congress

Gerry Walter, Planning Research Corporation

(These Comments are not Transcribed Verbatim.)

M. Goldbei^: It is possible to conceive any number of difficult tests. The important

thing is to establish tests which are meaningful and practical in terms of the

conditions to be encountered.

M. Capote: The tests described by Jane Clover of OCLl are standard tests that are used in thin film industries.

T. Albert: Test demonstrations should be performed in one's own (the user's)

environment.

C. Dollar: The National Archives and Records Service would prefer to see a

tabulation of OD^ data degradation rates and accompanying environmental

conditions, in order to establish archival storage conditions.

J. Bray: Media-independent test procedures to serve as a basis for performance

specifiations for the evaluation of archival media are preferred.

J. Dove: There are specialists in the physics of failure who might be able to offer

useful insights into media testing.

M. Goldberg: The best we might hope for is an impartial test procedure that puts a

relative rating on any media that is put forth. (A further comment was made that

there should be "classes" of tests for media that is designed for various

applications.)

M. Deese: There is a need for tests that would be representative of improper media

handling ("ape and banana" tests).

184
p. Adelstein: Such tests should be kept distinct from aging characteristics.

G. Walter: There should be a distinction between the requirement for the life of a material, versus the means of testing against this requirement. If magnetic tape is to be replaced, the media should have a life at least equal to that of magnetic tape.

T. Albert: We have experienced some loss of data on magnetic tape. 0D3 media

tends not to deteriorate with use, which distinguishes it from other media-which

may be subject to wear, fading, and other changes due to handling and environment.

The United States Geological Survey's storage requirements are for a minimum of 10

years.

Floor: A storage requirement of 5 to 7 years for medical images was noted as desirable although NIH has a requirement to keep its images "forever."

P. Sparks: The U.S. Library of Congress has documents and records that need to be

kept forever. Therefore, they attempt to use the most reliable media for secondary

format presentation. What they need to know is the reliability of the disk and when

it is advisable to transfer data from one disk to another.

K. Hughes: The United States Patent Office is not presently planning on the use of

0d3 as a permanent storage method. They rely on microfilm as an archival backup

medium. They are interested in OD^ from the standpoint of its effectiveness as a long-term storage medium, and for potential use in an active image retrieval

system.

E. LaBudde: There is a need to distinguish among qualification tests for acceptance,

stress tests, and aging tests of optical media.

P. Savage: Seismic data is considered permanent. Currently, Shell Oil samples the

data tested for degradation and these are recopied as needed. It is not likely that

Od3 could be backed up with any other technology. Shell will assess OD^ first with

non-critical applications.

185
2.4 WHAT IS A DATA INTERCHANGE STANDARD?

A Magnetic Media Example

By Michael Hc^an

National Bureau of Standards (NBS)

Key words: compatibility; formatted; interchangeability; label and file structure;

magnetic media; recorded; user.

Mr. Hogan discussed two types of magnetic media: computer tapes and flexible disk

cartridges (FDC). He presented figures on the number of drives and the amount of

media being shipped annually.

(1) 1983: 1/2 inch computer magnetic tape

35,867,000 reels

$538M value

(2) 1985: 1/2 inch computer tape drives

136,000 drives

$1,414M value

(3) 1983: flexible disk cartridges

$400 M value

(4) 1985: flexible disk cartridges

$1,080M value

(5) 1985: flexible disk cartridge drives

12,020,900 drives

$5,231. 9M value

For each of these two types of magnetic media, a family of three standards is used

to facilitate data interchange, representing three levels of compatibility.

1. Unrecorded or unformatted. This specifies the physical and magnetic

properties of the unrecorded media and assures the interchangeability of media

derived from various sources.

2. Recorded or formatted. This is for recorded media. It includes the code (e.g.,

American Standard Code for Information Interchange (ASCII)), data and track

format, and modulation method to assure compatibility and interchangeability

among information processing systems.

3. Label and file structure. Label and file structure deals with the recorded labels

and file structure to facilitate the exchange of information on the recorded

medium among different users and information processing systems.

186
Each level of compatibility may or may not have an impact on the various design areas of an information processing system. See table 1. These media standards are

not intended as procurement specifications but can be incorporated in such

specifications. For instance, error definitions are stated in the standards, but

requirements on error rates must be specified by the user in the procurement

specification. The standards are considered to be the minimum requirements

necessary to achieve data interchangeability.

These magnetic media standards have been prepared under the auspices of the

American National Standards Institute (ANSI), the International Organization for

Standardization (ISO), and the European Computer Manufacturers Association

(ECMA). See tables 2 and 3. Various time scales are involved in the preparation of

standards, typically in the range of 3 to 7 years. These standards are dynamic and

therefore can be revised as conditions dictate, as technological changes influence

the need for update.

Mr. Hogan alluded to the current status of microfloppy magnetic disks. There are

currently four diameters which are devoid of commonality. This type of situation is bewildering to potential users, many of whom may choose to avoid the technology

altogether until they see which of the various sizes is most likely to dominate.

Mr. Hogan suggested that one solution to the problem of data interchange among

these disk technologies might be to write standards on formats, labels, and file

structures. These type of standards could be developed even though the media are being marketed in various physically-incompatible sizes. These standards would

then be in place, at such time as the market coalesces around a particular disk size.

Mr. Hogan voiced an urgency for the development of OD^ standards on a worldwide

basis. He advised those involved in establishing the standards to remain active

beyond the formulation of draft standards, which will be written for the U.S. sector

of the Od3 industry, and to coordinate among the different standards bodies in order

to achieve multinational commonality.

187
O

<

W

a,O

I I I I c^- c-. X X X X

w

O

o

o

>»—

I

Q

<

Q

W

c<- X X <>•

X X X X

X X e- >•

X X X

5CO e-i w -a

Cm o o

.4-1 CD 5 m

00 ^

Q *

c o

CO

c

CObeo

X X X X XXX

^ a:

CO

Q

COo

<u o

o

"eo ^«

o c

<

O

ft, •J<

oI—

I

c/)

a.

CO oE

Eo

CO o

t—( CO

3

cr c

o o ^ o o o

CO CO CO +->•«-'+->

CO CO CO

O

<

o

J

<

U

o

o

E 1^ 5 o o

>

#—f i-H CO CO O V

bi'bJD O O

V V

CO CO E E

Q> 0) S

<«-i T3 Q.

II II X C^-

toSi

188
Table 2. Computer Tape Standards

(Hogan - National Bureau of Standards)

Unrecorded and Recorded Standards

TYPE OF MEDIA ANSI ISO ECMA

(X3B1) n^97/SCll) (TC17)

Unrecorded Tape, X3.40-1976 ISO 1864-1975 62-1980

12.7 mm (1/2 in) Wide

7-Track, 8 cpmm ISO 1861-1975

(200 cpi), NRZl

9-Track, 8 cpmm X3.14-1973 ISO 1862-1975 -

(200 cpi), NRZl

9-Track, 32 cpmm X3.22-1973 ISO 1863-1976 62-1980

(800 cpi), NRZl

9-Track, 63 cpmm X3.39-1973 ISO 3788-1976 62-1980

(1600 cpi), PE

9-Track, 246 cpmm X3.54-1976 ISO 5652-1983 62-1980

(6250 cpi), GCR

Self-Loading Cartridges X3.85-1981 ISO 6098-1982 56-1978

for 12.7 mm (1/2 in) Wide

Magnetic Tapes

Labelling and File Structure Standards

(X3L5) (TC97/SC15) (TC15)

12.7 mm (1/2 in) Wide X3.27-1978 ISO 1001-1979 13-1978

Magnetic Computer Tapes

189
Table 3. Flexible Disk Cartridge (FDC) Standards

(Hogan - National Bureau of Standards)

Unformatted and Formatted Standards*

TYPE OF MEDIA

200 mm (8 in) FDC

One side, 6,631 bprad,

1.9 tpmm (48 tpi)

Two side, 6,631 bprad,

1,9 tpmm (48 tpi)

One side, 13,262 bprad,

1.9 tpmm (48 tpi)

Two side, 13,262 bprad,

1.9 tpmm (48 tpi)

130 mm (5 1/4 in) FDC

One side, 3,979 bprad,

1.9 tpmm (48 tpi)

Two side, 7,958 bprad,

1.9 tpmm (48 tpi)

Two side, 7,958 bprad,

3.8 tpmm (96 tpi)

ANSI

IX3B8)

X3.73-1980

X3B8/78-140

(3rd draft)

X3B8/78-139

(3rd draft)

X3B8/82-73

(9th draft)

X3.82-1980

X3B8/82-79

(6th draft)

X3B8/82-78

(4th draft)

ISO

ITC97/SC11)

ISO 5654/1-1982

ISO 5654/2-1982

ISO 7065/1-1982

DIS 7065/2

ISO 6596/1-1982

DIS 6596/2

DIS 7487/1

DIS 7487/2

New Work Item

Approved

ECMA

(TCI 9)

54-1978

59-1979

69-1981

66-1980

70-1981

78-1982

200 mm (8 in) FDC

One side

Two side

130 mm (5 1/4 in) FDC

Two side

Labelling and File Structure Standards

(X3L5) (TC97/SC15)

monitor ISO

monitor ISO

monitor ISO

DIS 6863

DIS 7665

DIS 7665

(TC15)

58-1981

67-1981

Note: To date, the ISO and ECMA standards include track format requirements while

the ANSI standards do not.

190
3. DAY 3: Friday, June 3, 1983 - THE PURSUIT OF

od3 data interchange standards

3.1 SESSION I - PANEL DISCUSSION: WHAT 0D3

DATA INTERCHANGE STANDARDS ARE POSSIBLE

FOR THE UNRECORDED 0D3 MEDIA UNIT?

CAN A STANDARD TEST PROCEDURE FOR

UNRECORDED MEDIA CHARACTERISTICS BE

APPLIED ACROSS A RANGE OF MEDIA?

Panel Participcmts:

Peter Adelstein, Eastman Kodak Company

Miguel Capote, Optical Coating Laboratory, Inc. Mike Deese, Storage Technology Corporation

John Dove, U.S. Air Force

Larry Fujitani, Optimem (Moderator)

Mark Goldberg, National Security Agency

Edward LaBudde, LaBudde Engineering

Roland Malissin, Thomson CSF

Boris Muchnik, Storage Technology Corporation

Noel Proudfoot, Eastman Kodak Company

Delbert Shoemaker, Shoemaker Associates

(The Following Comments are not Verbatim:)

L. Fujitani: I have been asked by the Chair to define OD^ unrecorded media, which

is Od3 media on which the user has not yet entered data. Now, let us discuss the

possibilities and priorities for data interchange standards for the unrecorded OD^

media unit.

R. Malissin: Standardization priorities should be given to mechanical, optical, and

read/write factors. A guideline and definitions are necessary starting points.

Moreover several standards are to be defined from low-end products to high-end

products. For instance, a 305 mm (12 in) disk containing 109 bytes of data is a medium -end product which could be a standard. A high-end product could be

derived from this first one by increasing either the bit density or the number of

levels per bit and could give rise to another standard.

P. Scheinert: There are many differences in the design of OD^ media and systems.

Among these are the different disk diameters, optical path thicknesses, and

recording surface configurations. Diameters may be changed in order to promote

data interchange, and it is conceivable that the same recording surface chemistry can be applied to disk areas with different dimensions. However, the optical path

thickness of the disk is unique to a particular media/system technology. This aspect

of the surfaces and their responses may be a starting point for standardization, since

it is a key factor to 0D3 data interchange.

191
L. Fujitani: Can a standard test procedure for unrecorded media characteristics be

applied across a range of media?

M. Capote: The same specific tests should not be used for media which are intended

for different applications. Factors such as recording wavelengths, lasers employed,

data rates, and storage capacities must be considered.

P. Scheinert: A series of standardized test methods may be a good approach,

J. Verhoeven: These test methods must be, together with definitions, included in

the setup of the standards. It should follow already settled definitions and

approaches (guidelines) as much as possible. This facilitates the application of

standard test procedures across a range of media.

N, Proudfoot: There are doubts that a single standard test method could be

universally applied.

M. Capote: Currently, there are very few products in existence. Therefore, media

manufacturers should establish their own internal standards for various critical

factors. There are no great problems foreseen in bringing existing products into

conformity.

Floor: Magnetic tape specification testing in the 1950's was an underdeveloped

process. It was customary to evaluate tapes on the basis of their operational

performance rather than on specific physical/magnetic qualities. It isn't necessary

to solve every problem in order to achieve an initial standard. To develop usable

standards, OD^ unrecorded standardization should start with a standard at the level

where most products will perform. Test methods for media performance are part of

the standard's appendix, rather than the standard itself.

N. Proudfoot: I would like to propose the following list of potential parameters for

OD^ unrecorded media standardization. (These parameters should be discussed

relative to the reference plane.)

(1) Sizes of disk (begin with one or more sizes)

(2) Location of recording layer

(3) Thickness (perhaps)

(4) Mechanical interface

(5) Recording zone

(6) Imbalance (perhaps)

(7) Clamping area

B. Muchnik: Ninety percent of the factors for 305 mm (12 in) and 356 mm (14 in)

disks would overlap (although some values would be different).

The following list of OD^ unrecorded media parameters was formulated by panel

members:

(1) Geometric

192
Unrecorded Media Parameters, continued

(a) Inside diameter (ID)

(b) Outside diameter (OD)

(c) Reference plane

ifii T.Of*fltinn of i*Pf»nrHincT lo\7*»r

(e) Recording zone

(f) Thickness

(g) Clamping zone

(h) Handling zone

(2) Mechanical

(a) Radial runout

(b) Radial acceleration

(c) Axial runout

(d) Axial acceleration

(e) Unbalance

(f) Concentricity

(g) Mass

(h) Warp angle

(i) Tilt angle

(j) Revolutions per minute (RPM)

(3) Optical

(a) Optical path length

(b) Birefringence

(c) Wavelength

(d) Reflectivitv

(4) Environmental factors

(5) Pregroove information

(6) Signal considerations

(a) Sensitivity

. Write

. Read

(b) Signal-to-noise ratio

L. Fujitani: Please comment on the OD^ parameters, as they have been listed.

M. Goldberg: It would be useful to note what disk parameters would be easy to

change and those that would be difficult.

L. Spruijt: An OD^ drive may be able to compensate for some differences among

media characteristics, using initialization procedures.

193
Floor: A lower-order consideration might be to include a human-readable region

which would contain disk identification, serialization, and other information to ensure that the media will be used correctly in a remote location.

J. Dove: The term "mark type" might be useful when specifying recorded data,

rather than referring to specific methods of writing such as holes or pits.

M. Deese: Relevant to the discussion of what standards are possible, consider a "concrete walkway to the door" syndrome, in which people pour a walkway to where

they think the door is going to be. This can be a useful starting point, but this

walkway must be flexible so as to accommodate later changes.

L. Fujitani: There should be some common definitions written, before separate

groups develop standards for different products, which then couldn't be

cross-compared.

P. Adelstein: The standardization effort should concentrate on what is possible,

rather than struggling with questions on which there is no present consensus.

D. Shoemaker: It might be useful to formulate lists of those things that are easy to

agree on, those that are difficult, and those that are impossible.

M. Goldbei^: Within families of standards, a prioritization should be made based on

the difficulties of achieving the standards.

M. Capote: Among the four manufacturers presently making 356 mm (14 in) disks,

probably 50 percent of the items listed by the panel could be agreed upon.

B. Muchnik: There could be differences in viewpoint among those who make media,

those who make drives, and those who make both.

M. Goldberg: Changing even the simplest parameter may cause a ripple effect in

the overall system, and this should be avoided.

E. LaBudde: The basis for standardization has been identified, and there will be

families of standards for different manufacturers. Workshop participants are

invited to submit working papers, in order to establish their parochial interests.

194
3.2 SESSION II - PANEL DISCUSSION: WHAT STANDARDS

ARE POSSIBLE FOR THE 0D3 CARTRIDGE?

Panel Participemts:

John Bray, NCR

Mike Deese, Storage Technology Corporation

Larry Fujitani, Optimem

Martin Levene, RCA (Moderator)

Pat Savage, Shell Development Company

Louis Spruijt, Optical Media Laboratories

The following list of OD^ cartridge parameters was formulated by the panel

members:

(1) Geometry (dimensional limits)

(2) Mounting reference - surface or points

(3) Optical path

(4) Environment

(5) Keying for positioning and engagement in drive

(6) Label for ID (identification)

(7) Write inhibit

(8) Avoidance of separation of disk from cartridge

Two disk categories were recognized by the panel:

(1) Disks remain in cartridge during operation

(2) Disks slide out of cartridge during operation

M. Deese envisioned an "envelope" specification rather than tight dimensional

specifications. He offered the following list of candidate parameters for OD^

cartridge standardization:

(1) Physical size and weight

(2) Keying for machine insertion into drive

(3) Restraint of cartridge in drive

(4) Machine and/or human-readable ID

(5) Disk support

(6) Disk removal for operation in drive

(7) Tamper proof and encroachment witness indicators

(8) Over-limit temperature/humidity indicators

(9) Machine handling features to facilitate loading

(10) File protect or write inhibit

(11) Cartridge present, mounted, and ready sense feature

195
(The Following Comments are not Verbatim:)

M. Levene: Please comment on the standardization of the cartridge parameters

that have been listed.

L. Spruijt: A reference plane should be used for the disk, but not for the cartridge;

the spindle would be the reference for the system. However, a window cartridge

imposes additional standards requirements.

M. Levene: There is an interface between the cartridge and the drive. In a

multiple-disk access system, there is also an interface between one cartridge and

another. Cartridge bowing could be significant in the latter interface.

P. Savage: There is a risk of a disk separating from its correct cartridge—for

example, during a maintenance operation. Hence, labeling on the cartridge only

would not guarantee that a disk and its "mate" cartridge would be together.

Therefore, both the disk and its cartridge should be labelled. The practice with

magnetic tape is to label the reel rather than the container.

Floor: There should be both machine-readable and human-readable ID's on the disk

itself.

J. Bray: There are other specifications to be considered such as flammability. (It was explained that this and similar points belong in the procurement specifications,

rather than in the standards.)

M. Deese: There is a need for the same size cartridge for both 305 mm (12 in) and

356 mm (14 in) disks, and possibly for smaller disk sizes as well, in order to

facilitate interchangeability in automated disk handling devices.

P. Savage: A distinction should be made between outside dimensions of the

cartridges, which wiU be standard sizes, and their inside dimensions, which wiU vary

to accommodate different disk sizes.

M. Deese: Considering OD^ cartridge standardization, start with the interface

between the cartridges and the drive, and approach the interface with the media

later.

196
3.3 SESSION III - PANEL DISCUSSION: WHAT STANDARDS

ARE POSSIBLE FOR THE RECORDED 0D3 MEDIA UNIT - DATA FORMAT, LABELLING, AND FILE STRUCTURE?

DISCUSS INTERFACE STANDARDS THAT ARE

POTENTIALLY APPLICABLE TO 0D3

Panel Participants:

Peter Adelstein, Eastman Kodak Company

WiUiam Burr, National Bureau of Standards

Larry Fujitani, Optimem

Mark Goldberg, National Security Agency

Edward LaBudde, LaBudde Engineering (Moderator)

John Riganati, National Bureau of Standards

Philip Scheinert, Burroughs Corporation

Jan Verhoeven, Optical Media Laboratories

(The Following Comments are not Verbatim:)

E. LaBudde: The pro^ct of standards for the following parameters of OD^

recorded media will be discussed in this session:

(1) Physical/optical format

(2) Data record format

(3) Logical format

(4) File format

E. LaBudde: The standardization factors for OD^ unrecorded media which were

discussed in Session I could be verified rather easily with basic measurement

equipment, whereas the factors related to recorded media (to be discussed in this

session) are substantially more involved. Some of these include pregrooved or prerecorded material, modulation codes, sync patterns, and data protection

features.

L. Fujitani: It is important to differentiate between factors that are drive

dependent and those factors that are system considerations. The physical/optical,

data record, and logical formats are known to affect the drive/controller.

P. Scheinert: Everyone is coming up with different formats; this makes interchange

difficult. However, a novel approach, if possible, would be to use a plug-in card to

adapt from one format to another.

L. Fujitani: The applications would drive the file formats, and they might be

significantly different from previous ones.

P. Adelstein: A standard can't be formulated around a single vendor; there must be

at least two.

197
Floor: The sector size probably can't be standardized. But an identification flag

could be put at the beginning of each sector, tying it to the identification of the

disk.

J. Verhoeven: There should be both track and sector identifiers.

The following list of candidate items was formulated by the panelists to describe the

recorded media parameters that could be considered for potential standardization:

(1) Physical/optical format

; (a) Tracks

(b) Tracking

(c) Addressing

(2) Data recording format

(a) Modulation

(b) Timing

(c) ECC

(3) Logical format

(a) Labelling

(b) Sectors/blocks

(4) File format

(a) Structure

(b) Directory

(c) Update

W. Burr: The most common block size is 256/512; what block size is current OD^

hardware and software set up to accommodate?

E. LaBudde: The factor of block size would be relatively easy to handle in the

controller.

Floor: There was a discussion regarding the handling of patents in the

standardization process.

J. Riganati: If a patent holder is a party to the formulation of a standard and agrees

to it, that patent holder is expected to grant a license at reasonable cost on an equal

basis to the users of the standard. If a patent holder is not a party, then the users must beware. Standards carry disclaimers warning of this situation. It is the

function of the standards processing organizations to assure that there will be equal access to known patents before a standard is promulgated.

198
L. Fujitani: People are interested in acquiring OD^ devices and gaining experience

with them. This will begin to occur before the standards are formulated and will

probably result in useful feedback and refinements in design.

M. Goldberg: If only one manufacturer is involved, standards aren't actually needed;

standards are needed only when interchangeability between suppliers is required.

3.4 SESSION IV - PANEL DISCUSSION: WHAT STANDARDS

ARE POSSIBLE FOR 0D3 CHANNEL I/O AND

STORAGE SUBSYSTEM INTERFACES?

M. Deese: SESSION IV, "What Standards are Possible for Data Transfer and

Command Interfaces?" will not take place, since standardization for data transfer

could be handled by an ANSI interface committee.

D. Shoemaker: I suggest that the SPARC (Optical Disk) Study Group establish their

requirements for the OD^ interface and advise the X3T9 committee of these

requirements so that work on the interface can be done in-line with the other

development.

I

199
3.5 SESSION V - THE PURSUIT OF OPTICAL DIGITAL

DATA INTERCHANGE STANDARDS

3.5.1 The Pursuit of 0D3 Data Interchange Standards

By Michael Deese

Storage Technology Corporation

Key words: European Computer Manufacturers Association (ECMA); optical disk;

project proposal; Standards Pleinning and Review Committee (SPARC); standards

development.

Mr. Deese presented an overview of standards activities relating to 0D3. He

explained that the initial step involves a project proposal, which can be written by

anyone and is submitted to the Standards Planning and Review Committee (SPARC).

In the case of 0D3, SPARC called for the formation of a Study Group. The first

standard, probably on unrecorded media, is expected about the third quarter of 1985.

One project proposal on OD^ has already been prepared, and two others are underway. A glossary subgroup is at work. In Europe, there is a study group

operating under European Computer Manufacturers Association (ECMA), chaired by

Dr. Jan Verhoeven of Optical Media Laboratory (OML). A matrix of possible

standards is under consideration, which could identify 15 to 20 standards, probably

groupable by families. Mr. Deese foresees 12 to 24 standards for OD^, which is comparable to the magnetic tape family of standards.

Mr. Deese enumerated the advantages of participating in standards development. It presents an opportunity for the exchange of ideas, which in itself is valuable, even if the completion of a standard is a long way off. The standards process allows

manufacturers to bring products to the marketplace in an orderly and responsible

manner, rather than overwhelming the users with a diverse array of products that

differ in relatively trivial ways and suffer from incompatibility.

200
3.5.2 A COST-BENEFIT IMPACT ASSESSMENT

OF 0D3 standardization

By Marco FioreUo

Titan Systems

abstract

This report presents a preliminary cost-benefit impact assessment of

promulgating information processing standards for the commercially

emerging Optical Digital Data Disk (0D3) Technology. The Federal

Government perspective is emphasized. The analysis includes:

estimates of the market penetration of the Od3 technology; basic

models of how standards can affect technology innovation and diffusion;

and, a preliminary assessment of the cost-benefit to the Federal

Government.

Key words: information processing standards; market penetration; mass

storage and retrieval; OD^ market projections; OD^ technology;

technology forecasting.

Executive Summary

The objective of this study is to determine the costs and benefits to the U.S.

Government for the establishment of standards for the optical digital data disk

(0d3) technology as it emerges into commercial acceptance, or to wait until it has

matured into commercially proven products.

0d3 technology, as used here, refers to the capability of producing high density,

digitally encoded optical storage devices which are suitable for use as computer

system peripherals device and media. To date, a number of pre-production

prototype OD^ systems have been developed, demonstrated, and evaluated.

Currently, commercially available products from different manufacturers, using

various recording media and designs, appear imminent and initial commercial sales are forecasted for the 1984-1986 time frame.

Due to time and resource limitations allocated in this study, we focused on the

potential OD^ Mass Data Storage and Retrieval (MDSR) market dealing with

applications that currently utilize some form of magnetic storage technology, to

record machine readable information.

It is recognized that this scope does not include potential GD^ "document scanning"

applications for rastor scanned information. Assessing the market for those

applications requires considerably more data collection and analysis than was

possible in this study. However, we feel that those OD^ technology applications will

follow and, to some degree, be affected by the diffusion and success of the OD^

technology in the market niche which is focused on in this analysis. In this study, we

have assumed that the most likely initial applications of OD^ technology will be in

those areas in which some form of computer storage media is currently employed,

and where that technology can be improved upon by the OD^ technology.

201
The magnitude of the magnetic MDSR market is significant - a recent survey of 70

Federal and commercial organizations with large data processing facilities indicates

that by 1987, such facilities anticipate requirements, on average, of over two trillion

characters of on-line (includes automatic access) storage and over three trillion

characters of off-line storage per installation.* The total population of such

installations is expected to be in the many hundreds.

Based on the anticipated cost/capacity comparative advantages of 0D3 technology

relative to the existing magnetic storage technology, the 0D3 technology is projected to penetrate the magnetic storage market significantly. In fact, some

forecasts estimate penetration to be as high as 60 percent by 1992. However, there are factors such as standardization effects, 0D3 technology risks, and improvements

in competing technologies which can cause significantly higher or lower OD^

technology penetration rates.

In normal market settings, there are many forces that can foster or retard the

acceptance and diffusion of a new technology. From an economic perspective, a

reduction in technical and market risks, for both making and using a product which

is in demand, can benefit both producers and consumers. If OD^ technology has a comparative advantage over current magnetic storage technology, for certain

established market applications, then it will be used to displace or augment the

current products which are used in these applications. To the degree that this

advantage holds, then accelerating the diffusion of the new technology can yield

additional benefits to both users and producers in a normal market.

One scenario that can be used to assess the economic impacts from technological

diffusion is to infer that as a result of reduced risks, attributable in part to

standards, the OD^ technology diffusion curve would be accelerated, therefore more

Od3 products would be utilized sooner than in the non-standards case. Further,

with more users creating a substantial demand, more suppliers would enter the

marketplace to produce and sell OD^ products. With an increase in competition (for

normal commodity markets), the supply curve typically shifts such that the product

price is reduced, relative to the products' price and quantity in the non-standard

setting.

The preceding scenario is plausible if the standards' functions are introduced in a timely manner and are compatible with the OD^ technology product and process life

cycle development. In past cases (e.g., disk storage devices), where the technology

was more mature relative to the precent status of OD^ technology, significant

savings of up to 40 percent have been realized or projected based on the logic of

that scenario.

For 0D3 technology, the following sequence of standards could be most effective in

helping to remove the principal technical and market barriers, and being compatible

with the current development state of OD^ technology:

* rKERR-82] Kerr, A., User Requirements; Results of a Mass Storage Survey, Digest of Papers; Hardware and Software Issues for Non-Storage Systems, Fifth

IEEE Symposium on Mass Storage Systems, October 26-28, 1982, Boulder, Colorado, IEEE Computer Society Press, N.Y. 1982.

202
(1) Information Standards - for terminology consistency, measurement, and

test specifications;

(2) Quality Standards - to define the performance of the technology, including

media reliability and durability;

(3) Compatibility Standards - for the I/O channel and 0D3 system, initially and

eventually full media compatibility.

(4) Variety Reduction Standards - for various disk sizes, after the initial media

technology has produced commercial products.

These standard functions should focus on media type, data format, disk

configuration, media stability, and level and type of interchangeability.

For the data used in this analysis to define the base case or "no standards" case, the

estimated mean cost advantage of Od3 over magnetic media per billion (lO^)

characters stored on-line is $76,000 one time costs; plus $1,200 per year in recurring

costs, in 1983 constant doUars. Thus if an organization requires 100 billion

characters of on-line storage, the potential savings from utilizing OD^ technology

versus a 50:50 combination of magnetic tape and magnetic disk technology storage

is approximately $7.6 million in non-recurring costs and $120,000 per year in

recurring costs. Analogously, a one trillion character requirement would yield about

$76 million in non-recurring cost savings plus $1,200,000 per year in recurring cost

savings.

All of the above estimates and projections are subject to uncertainty about the

parameter values, impact factors, and underlying assumptions. The parameter

values used throughout are based on most likely values from the literature or best

estimates from experts. Changing the device and media costs substantially would

affect both the base case and the standardization impacts. Given the linear model

forms, a change in the difference in device and media costs for the competing

technologies would result in proportional increases or decreases, depending upon the

direction of the change. These results are most sensitive to device hardware costs,

to media costs, and finally to database handling costs.

The most critical assumption is the expectation that the emerging OD^ technology

will demonstrate a comparative advantage (in price and storage performance) over

the competing magnetic media technology. If the comparative advantages hold, the

actual savings estimates for OD^ technology and its related standardization impacts

will probably be much higher than those estimated in this study. On the other hand,

the magnetic storage technology is still being improved (historically it has improved

its cost per storage capacity ratio by 20 percent compounded annually for the last

five years), and significant advances are in their experimental stages. Vertical

recording is an example of a potentially important new magnetic recording

technology.

The estimated standardization impact value of 10 percent on the OD^ technology is a conservative number. In fact, where standardization has been instrumental in

reducing risks and increasing competition, price reductions of over 40 percent has

been realized in Federal Government purchases.

203
A timely and effective set of standards as outlined in the above categories can enhance the diffusion of 0D3 technology, and certainly reduce consumer and

producer risks. However, enhancements and benefits from standardization that can

accrue to producers and consumers can only occur if the basic 0D3 technology has an

actual economic advantage relative to competing technologies.

For the above computations and underlying assumptions, a case can be made for the

strong diffusion of 0D3 technology and that additional marginal benefits can accrue from standardization. At a conservative standardization impact of 10 percent on

the device and media prices, the estimated $600,000 for standards development

costs can be recaptured during procurement in the Federal sector when as few as 80

billion characters are stored using standardized 0D3 technology. If the mean value

estimates for 1987 noted above are taken as representative for single, large data

processing installation storage requirements, then the 2.2 trillion characters for

on-line storage alone would yield a return 25 times the standard's development

costs. Where multiple installations are considered, as well as the forecasted

off-line requirements, the non-recurring standardization savings can be

substantially over $100 million, in 1983 dollars. Though substantial, that impact by

comparison is less than one-tenth of the value of the 1980 Federal investment in

magnetic storage devices and media, and approximately one-third of the Federal

Government expenditures projected for 1983-1988 for MDSR requirements.

204
3.5.3 TIMING THE PURSUIT OF OPTICAL

STANDARDS - WHEN IS IT RIGHT?

By Joseph Zajaczkowski

Sperry Corporation

Key words: consensus; de facto; edict, standards process; timing of standards.

Mr. Zajaczkowski pointed out that there are three methods of arriving at standards:

de facto, edict, and consensus. In Europe, standards are more often mandated by

edict; in the U.S., there is heavy reliance on the voluntary standards process

(consensus). The correctness of the timing of a standard is always determined by

hindsight.

The objective of standardization is to provide an agreed to arbitrary solution to a

recurring problem along with industry accepted measurement methods. Several

factors are important in the timing of standards: the technology must be

understood, it must be cost-effective, and the standards should satisfy a need. The

difficulties associated with even modest changes should not be underestimated.

Mr. Zajaczkowski observed that committees tend to have only a few people actually

doing a significant amount of work, and hence proceed more slowly than might be

expected. A document does not have to reach completion to begin serving a useful

purpose. Standards participants should establish the areas of agreement and build on

these. He stressed the importance of being involved in the standards process.

205
3.6 THE ROLE OF THE NATIONAL BUREAU OF STANDARDS (NBS)

In the Future Development of 0D3 Standards

By Michael Hogan

National Bureau of Standards (NBS)

Key words: calibration; Federal Information Processing Standards (FIPS);

measurement standards; NBS Standard Reference Material (SRM) Program.

Mr. Hogan reviewed the evolution of NBS and its legislative authority. NBS is a Bureau of the U.S. Department of Commerce. It was established by Congress in

1901 to help ensure the compatibility of measurement standards needed by industry,

consumers, the scientific community, and other government organizations. The

Bureau has limited resources with which to carry out a very broad mandate.

The NBS role in ADP (automatic data processing) was specifically defined by the

Brooks Act in 1965, which establishes central management in the Federal

Government for procuring and utilizing computers and their associated products.

Specific roles were assigned to NBS, the General Services Administration (GSA), and

to the Office of Management and Budget (OMB).

Mr. Hogan described the NBS Standard Reference Material (SRM) program which to

date has produced over 1,000 types of SRM's. These are calibrated substances and

materials which are used in areas where the complete measurement methods cannot

be fuUy described on paper, but instead must be carried out with reference to

calibrated samples. Included among the SRM's are reference magnetic tapes and

disks for use in the manufacture and testing of magnetic media and associated

devices, and in the calibration of operational tape and disk drives. NBS also

produces standard resolution test targets for photographic imaging technologies.

NBS has a key role in the development and promulgation of Federal Information

Processing Standards (FIPS). Development of these standards is accomplished to the

maximum extent possible through voluntary standards organizations, such as American National Standards Institute (ANSI), National Micrographics Association

(NMA), and International Organization for Standardization (ISO). NBS staff

members participate actively in these organizations. For the most part, the FIPS

adopt the relevant voluntary standards and cite them for application within the

Federal Government.

The National Bureau of Standards/Institute for Computer Sciences and Technology

(NBS/ICST) is also deeply involved in the preparation of FIPS Guidelines and Special

Publications which provide guidance, explanatory material, and operating procedures

for Federal ADP managers and their staffs. For example, an NBS Special

Publication entitled Care and Handling of Computer Magnetic Storage Media

(SP500-101), authored by Sidney B. Geller was published in June 1983. This NBS

Special Publication deals with the physical/chemical preservation of computer

magnetic storage media—principally computer magnetic tapes—and their stored

data, through the application of proper care and handling methods, under various

conditions. It emphasizes the media handling methods and environmental conditions

which should be instituted during the course of controllable day-to-day and

206
long-term archival storage activities. It also considers measures which can be

initiated during media transit and in the aftermath of catastrophic or uncontrollable

events.

Another ICST product is a bibliography entitled A Bibliopaphy of the Literature on

Optical Storage Technology which wiU be published in the near future. This

bibliography will contain citations on video disk recording, holographic storage, and

many papers of a background nature in addition to the OD^ technology papers.

Several citations relating to 0D3 storage media have been annotated. Over 100

patents related to optical data storage will also be cited in this bibliography. For

further information, contact J. R. Park, National Bureau of Standards, Institute for

Computer Sciences and Technology, Room A216, Building 225, Washington, D.C.

20234 (telephone: 301/921-3723).

NBS can be expected to be active in the development of FIPS for 0D3 as the

development of standards in this area proceeds within the national and international

standards arena.

207
4. Appendix A. List of Symbols, Abbreviations, and

Acronyms Used in These Proceedings

A amperes

A4 Basic Size of Paper 210 x 297 mm (8.3 x 11.7 in)

ADP automatic data processing

A-K "a through k," engineering drawing dimensions, 8.5 x 11" (A) through

drawings 34" wide by lengths up to 150 ft (roll length)

ALT Administrative Lead Time

ANSI American National Standards Institute

ARRADCOM Armament Research and Development Command

ARRCOM Armament Materiel Command

ASCII American Standard Code for Information Interchange

ASTM American Society of Testing and Materials

BER bit error rate

bit binary digit

bpi bit per inch

b/pixel bit per pixel

c Celsius

CAD/CAM computer aided design/computer aided manufacturing

Air CAV constant angular velocity

CECOM Communication and Electronic Command

L't D cipher feedback mode

CLV constant linear velocity

cm centimeter (=10~2 meter)

CNR carrier-to-noise ratio

COM computer output microfilm

CPU central processing unit

CRC/ECC cyclic redundancy check character/error correction code

CRT cathode ray tube

DARCOM Materiel Development and Readiness Command (U.S. Army)

DARPA Defense Advanced Research Projects Agency

dB decibels

A delta, "change in"

DES Data Encryption Standard

DMA direct memory access DMSP data management support package

DOD Department of Defense

DRAW direct read after write

DSREDS Digital Storage Retrieval Engineering Data System

E Size 34 x 44" (engineering drawing dimensions)

ECC error correction code

EDAC error detection and correction

ECMA European Computer Manufacturers Association

EIA Electronic Industries Association

ERADCOM Electronic and Research and Development Command

208
fig. figure

FIPS Federal Information Processing Standards

FDC flexible disk cartridges

FWHM fuU-width-half-maximum

g gram

Hg mercury

HRMR human read/machine read

Hz hertz

IBM International Business Machines Corp.

ICST Institute for Computer Sciences and Technology

ID identification, as in file structure and labelling: volume ID

ID inside diameter (disk dimension)

lEC International Electrotechnical Commission

IGES Initial Graphics Exchange Specification

in inch

I/O input/output

IPI Intelligent Peripheral Interface

ISO International Organization for Standardization

ITSMB Image Technology Standards Management Board

JCL job control language

K kilo (103)

Km kilometer

Laser Light Amplification by Stimulated Emission of Radiation

LSI large scale integration

Ipi lines per inch

log logarithm (base 10)

MAC message authentication code

Mb 106 bytes

Mbytes/s 10^ bytes per second

MERADCOM Mobility Equipment R<5cD Command

mi mile

MICOM Missile Command

mm millimeter

mV millivolt

mW milliwatt

MSS mass storage system

MTBF mean time between failures

NA numerical aperture

NARS National Archives and Records Service

NATICK R<5cD Labs

NBS National Bureau of Standards

NCAR National Center for Atmospheric Research

nm nanometer (10"^ meters)

209
NMO number of critical microperations

NSA National Security Agency

NTE not to exceed

NTSC National Television System Committee

OCLI Optical Coating Laboratory, Inc. OD outside diameter (disk dimension)

0D3 optical digital data disk

ODL optical disk library

OEM original equipment manufacture

OML Optical Media Laboratories

OMU optical media unit

OSU optical storage units/s

P power

% percent

PH denotes photographic standards committees

RADC Rome Air Development Center

RAM random access memory

RC Resin Coated

RH relative humidity

RMS root-mean-square

RPM revolutions per minute

R/W read/write

s second(s)

SCSI Small Computer System Interface

SEM scanning electron micrograph

SMD storage module drive

SNR signal-to-noise ratio

SPARC Standards Planning and Requirements Committee

SPIE Society of Photooptical Instrumentation Engineers

SRM standard reference material

STC Storage Technology Corp.

TACOM Tank Automotive Command

TAPPI Technical Association of the Pulp and Paper Industry

TBM Terabit Memoryl""^ (registered trademark of AMPEX Corporation)

TDP technical data packages

tm trademark

35 mm thirty-five mm film (24 x 36 mm format)

TSARCOM Troop Support and Aviation Materiel Command

USAF United States Air Force

uses United States Geological Survey

VLSI very large scale integration

W/R write/read

210
Years Between Failures

degree

degrees Celsius

Celsius

lambda (wavelength)

theta (angle)

per (a.g. pixels/mm read pixels per millimeter)

micro (=10~6)

microinch (=10~6 in)

micrometer (=10"6 m); also referred to as a micron

inch(es)

211
5. Appendix B. Optical Digital Data Disk

Preliminary Glossary of Terms

This preliminary glossary has been written and will undei^o further development by

a task group of the XS^PARC Optical Digital Data Disk Study Group. It offers a

current set of definitions encountered in the OD^ technology, that could be applied

to OD^ standardization.

NOTE: The text and illustrations in this worktop proceedings were developed

independently of this glossary.

X3/SPARC Optical Disk Study Group

Optical Digital Data Disk Preliminary Glossary

address (ISO) - A character or group of characters that identifies a register, a

particular part of storage, or some other data source or destination.

axial acceleration -- The peak apparent acceleration of recording layer in a direction

normal to the reference plane (meters per second squared) at the operating

rotational speed (rpm).

axial total indicated runout (TLR) - Maximum peak-to-peak apparent axial

displacement (micrometer) of the recording layer perpendicular to the reference

plane at the operating rotational speed (rpm).

b£Lseline reflectivity - The reflectivity of unwritten, ungrooved media.

beam diameter, l/e^ - The diameter of a gaussian beam, measured at a distance of

l/e2 from the baseline intensity.

beam diameter (FWHM) - The diameter of a gaussian beam measured at a distance

where the beam intensity is one half of the peak intensity.

bi-refringence - see double-pass optical retardation

bit error - see error

bit error rate (BER)

carrier - the rms carrier level in dBm in a specified bandwidth signal centered at the

fundamental (carrier frequency) of a monotone recording. The input is a 50% duty

cycle square waveform.

carrier-to-noise ratio (CNR) - The ratio of the carrier to the noise level in dB.

212
X3/SPARC 0D3 Study Group Preliminary Glossary

eartridfee - A device containing an optical disk which serves to protect the disk from

damage due to physical handling and to facilitate disk interchange. The cartridge

may also provide space for physical labeling, features for write protection,

provisions for automatic handling, and temperature and humidity sensors.

concentricity - The difference in the mechanical center locations of the centering

feature of the disk and any contour on the disk (such as a pregrooved track).

cyclic redundancy check character (CRC) - A character used in a modified cyclic

code for error detection and error recovery.

dBm - Decibels referenced to a one (1) millivolt level.

decibel (dB)

1. A unit to express the magnitude of a change in signal levels.

2. The difference in decibels between two signals is 20 times the common

logarithm (base 10) of the ratio of their voltages.

diode laser - see semiconductor laser

disk size - The nominal outside diameter of the disk without cartridge including a rim or ring (if any) (mm).

double-pass optical retardaticm - The maximum optical path difference (in

wavelengths) between any two coincident optical beams with orthogonal polarization

propagating twice through the protective layer at normal incidence.

entry face - The disk or cartridge face on which the read or write beam first

impinges.

environment, (grating - May include the temperature (degrees C) and relative

humidity (%RH) ranges for writing and reading disks with a specified maximum

gradient for temperature (degrees C per hour) and humidity (%RH per hour);

maximum dew point (degrees C); range of altitude (meters); and minimum

conditioning time when taken from an environment outside the operating

environment (hours).

envircmment, shipping - May include the temperature (degrees C) and relative

humidity (%RH) ranges for shipping recorded or unrecorded disks with a specified

maximum gradient for temperature (degrees C per hour) and humidity (%RH per

hour); maximum dew point (degrees C); range of altitude (meters); allowable levels

of shock (g's); and allowable duration.

envir<Miment, storage - May include the temperature (degrees C) and relative

humidity (%RH) ranges for storing recorded or unrecorded disks with a specified

maximum gradient for temperature (degrees C per hour) and humidity (%RH per

hour); maximum dew point (degrees C); and range of altitude (meters).

213
X3/SPARC 0D3 Study Group Preliminary Glossary

error (ISO) - A discrepancy between a computed, observed, or measured value or condition and the true, specified, or theoretically correct value or condition.

error correction code (ECC) - see error detection and correction code

error ratio - The ratio of the number of data units in error to the total number of

data units.

error detection and correction code (EDAC) - A family of methods in which

redundancy is added to a message in known fashion which is recorded with the

message. Upon readback, a decoder removes the redundancy and uses the redundant

information to detect and correct erroneous channel symbols.

fill factor - The l/e2 diameter of a gaussian beam at the entrance pupil divided by

the entrance pupil diameter.

full-width-half-maximum (FWHM) - see beam diameter (FWHM)

imbalance - The product of the total mass of the disk and the distance in the plane

of the disk between the center of gravity of the disk and the axis of rotation of the

disk (gm-cm).

index of refracti<Hi - The ratio of the phase velocity of light in a vacuum to that in a

specified medium. The index of refraction is invariably a function of the frequency

or wavelength of the optical radiation.

laser - An active electron device that converts input power into a intense beam of

coherent optical radiation. An acronym for Light Amplification by Stimulated

Emission of Radiation.

laser diode - see semiconductor laser

noise level - The level of rms electronic noise in dBm measured over a defined noise

bandwidth.

optical path length - The sum of the products of the index of refraction (n) and the

thickness of each layer (micrometer) between the entry face and the recording

layer.

protective layer - The material between the entry face and the recording layer

provided for mechanical protection of the recording layer and to defocus surface

dust and scratches.

radial accelerati<Mi - The peak radial acceleration of any track on the recording

layer relative to the axis of rotation of the disk (meters per second squared) at the

operating rotational speed (rpm).

radial total indicated runout (TlR) - Maximum peak-to-peak radial displacement

(micrometers) of any track on the recording layer,

recording layer - The disk layer on or in which the digital data is recorded.

214
X3/SPARC 0D3 Study Group Preliminary Glossary

recording layer read exposure - The maximum continuous read power (milliwatts) at

the readout wavelength at the full-width-half-maximum (FWHM) read spot diameter

allowed in the recording zone during readout at a specified linear velocity of the

recording layer (m/s).

recording layer reflectivity - The reflectivity (%) of the disk at a specified

wavelength measured through the protective layer (if any) at normal incidence.

recordii^ layer reflectivity uniformity - The peak-to-peak variation of the recording

layer reflectivity (% absolute) over the recording zone.

recording layer sensitivity - The minimum energy per mark (nanojoules per

micrometer squared at the FWHM diameter) required to produce marks meeting

specified carrier level using a specified nominal writing wavelength (nm) with a

specified pulse length (ns) and a specified linear velocity of the recording layer

(m/s).

reference plane - The plane normal to the axis of rotation of the disk drive spindle

defined by the contact surface with the disk drive.

second harmonic carrier - The rms carrier level in dBm in a specified bandwidth

centered at 2X the carrier frequency.

semiconductor laser - A laser in which stimulated emission of coherent light occurs

at QTX junction when electrons and holes are driven into the junction by carrier

injection, optical exitation or other means.

signal-to-noise ratio - The ratio of the time averaged signal power to the total noise

power (dB) over a defined bandwidth.

static deflection - The maximum distance a surface of the disk deviates from the

reference plane (mm) in a static condition.

strehl ratio - The peak irradiance of a real spot divided by the peak irradiance of an

aberration free (ideal) spot.

thickness, apparent - The thickness of an object as measured by optical means. The

apparent thickness equals the physical thickness divided by the index of refraction

of the object being measured.

thickness, physical - The thickness as measured by physical means (e.g., micrometer,

calipers, etc.). The physical thickness is considered the real or actual thickness.

unobstructed access - Access is termed to be unobstructed when the recording zone may be accessed by the read/write optical head scanning in from outside the outer

disk edge without raising or lowering the optical lens assembly, with the disk

mounted to the spindle.

warpii^ ai^le - The maximum angle (milliradians) between the axis of the disk and

the normal to the reference plane when the disk is properly clamped to the spindle.

The measurement should be made with the disk at a specified rotational speed (rpm).

215
X3/SPARC 0D3 Study Group Preliminary Glossary

working distance - The distance from the entry face to the closest point on the

read/write head objective lens assembly.

zone, clamping - A region of the disk which may be in contact with the spindle and a clamping mechanism.

zone, handling - A region of the disk which may be physically contacted by a

handling mechanism.

zone, mechanically accessible - The annular zone on and surrounding the disk which

the optical head and can access, unimpeded by the disk or cartridge structure, with

the disk mounted on a spindle.

zone, optical beam accessible - The annular subset of the mechanically accessible zone on the disk which can be accessed by the read or write beam.

zone, recordii^ - An annular subset of the optical beam accessible zone available to

the user for data storage.

216
6. Appendix C. Participants

National Bureau of Standards/National Security Agency Workshop on

Standardization Issues for Optical Digital Data Disk (0D3) Technology

June 1983

Dr. Peter Adelstein

Eastman Kodak Company

Manufacturing Technology Division

Bldg. 35, Kodak Park

Rochester, NY 14650

Mr. Ted Albert

U.S. Geological Survey

115 National Center

Reston, VA 22092

Mr. Paul Allison

Department of the Army

HQDA (DAAG-AMM-T, Allison)

Alexandria, VA 22331

Mr. Toshio Aoki

Disc Development Division

Sony Corp.

P.O. Box 10

Tokyo Airport

Tokyo 149, Japan

Mr. Thomas Bag^

National Bureau of Standards

Room A51, Bldg. 225

Washington, D.C. 20234

Mr. Robert Bender

Storage Technology Corp.

2270 South 88th Street, MD AF

LouisviUe, CO 80028

217
Mr. Wesley Brandhorst

ERIC Facility

4833 Rugby Avenue, Suite 301

Bethesda, MD 20814

Dr. Dennis Branstad

National Bureau of Standards

Room A216, Technology Bldg.

Washington, D.C. 20234

Mr. John Bray

NCR Canada Ltd.

580 Weber Street, N.

Waterloo, Ontario

Canada N2J 4G5

Dr. Thoin£is Brown

Machine-Readable Archives Branch

National Archives & Records Service

Washington, D.C. 20408

Mr. William Burr

National Bureau of Standards

Room A216, Technology Bldg.

Washington, D.C. 20234

Mr. James Burrows

Director, Institute for Computer

Sciences and Technology

National Bureau of Standards

Room A200, Admin. Bldg.

Washington, D.C. 20234

Dr. Patrick Call

Access Unlimited Inc. 1832 55th Street

Boulder, CO 80301

218
Mr. Miguel Capote

Optical Coating Laboratory, Inc. 2789 Northpoint Parkway

Santa Rosa, CA 95401-7397

Dr. Di Chen

Optical Peripherals Laboratory

1050 S. Academy Blvd.

Colorado Springs, CO 80910

Mrs. Jane Clover

Optical Coating Laboratory, Inc. Dept. 521-D

2789 Northpoint Parkway

Santa Rosa, CA 95401

Mr. Morris Cohen

NCR Corporation

16550 W. Bernardo Drive

San Diego, CA 92127

Mr. Anthony Concia

National Micrographics Association

8719 Colesville Road

Silver Spring, MD 20910

Mr. John Davis

IIT Research Institute

5100 Forbes Blvd.

Lanham, MD 20706

Mr. Michael Deese

Storage Technology Corp.

2270 S. 88th - Mail Drop AF

Louisville, CO 80028

219
Mr. James DeStefano

Dysan Corporation

5201 Patrick Henry Drive

Santa Clara, CA 95050

Dr. Charles Dollar

National Archives dc Records Service

Special Archives Division (NNS)

Washington, D.C. 20408

Mr. John Dove

Rome Air Development Ctr./COTA

Griffiss Air Force Base, NY 13440

Mr. David Fain

Integrated Automation

2121 AUston Way

Berkeley, CA 94704

Mr. R. Fiddes

H.M. Treasury

Central Computer & Telecomm. Agency

Riverwalk House

157-161 Millbank

London SWIP 4RT, England

Dr. Marco Fiorello

Titan Systems, Inc. 6833 Beverley Road - Suite 320

McLean, VA 22101

Mrs. Jean Freedman

National Bureau of Standards

Room A216, Technology Bldg.

Washington, D.C. 20234

220
Mr. Larry Fujitani

Optimem Div. of Shugart

350 Potrero Avenue

Sunnyvale, CA 94086

Mr. Joe Ganahl

IBM-FSD

18100 Frederick Pike - MS 110

Gaithersburg, MD 20878

Dr. Mark Goldberg

Department of Defense - R53

9800 Savage Road

Ft. George G. Meade, MD 20755

Mr. Michael Hogan

National Bureau of Standards

Room A216, Technology Bldg.

Washington, D.C. 20234

Mr. Thomas Hood

IBM-FSD

18100 Frederick Road - MS 110

Gaithersburg, MD 20879

Mr. J. Kent Hughes

U.S. Patent and Trademark Office

Office of Micrographic Systems

CP2-8A11

Washington, D.C. 20231

Mr. Terry Jcdinson

NCR

3718 N. Rock Road

Wichita, KS 67226

Mr. Jack Kellogg

Access Unlimited Inc. 1832 55th Street

Boulder, CO 80301

221
Dr. Theo Kooij

DARPA/TTO

1400 Wilson Blvd.

Arlington, VA 22209

Mr. Edward LaBudde

LaBudde Engineering Corp.

3401 Daniel Street

Newburry Park, CA 91320

Mr. Le<Miard Laub

Vision Three, Inc. 1400 Arroyo View Drive

Pasadena, CA 91103

Mr. Martin Levene

RCA Corporation

Advanced Technology Laboratories

Bldg. 10-8, Sec. 421

Camden, NJ 08102

Mr. Roland Malissin

Thomson-CSF

Domaine de Corbeville

Orsay, France 91401

Mr. Fred Marsh

U.S. Department of Energy

Technical Information Center

P.O. Box 62

Oak Ridge, TN 37830

Mr. Thomas Mayer

Optical Coating Laboratory, Inc. 2789 Northpoint Parkway

Santa Rosa, CA 95401

222
Mr. W. Meiklejohn

General Electric Company

Corporate Research <Sc Development

P.O. Box 8

Bldg. K-1, Room 3B38

Schenectady, NY 12301

Mr. Paul Meissner

National Bureau of Standards

Room A216, Bldg. 225

Washington, D.C. 20234

Dr. David Morin

Naval Ocean Systems Center

Code 7135

San Diego, CA 92152

Mr. Boris Muchnik

Storage Technology Corp.

MD-G6

2270 S. 88th Street

Louisville, CO 80028

Mr. Hiroyasu Murakami

Toshiba Corp.

70 Yanagi-Cho

Saiwai-Ku, Kawasaki

210 Japan

Mr. Steve Murakami

Matsushita Technology Center

One Panasonic Way

Secaucus, NJ 07094

Mr. Kenneth Nolan

IBM

533/025-1

P.O. Box 1900

Boulder, CO 80302

223
Mr. Bernard 0*Lear

National Center for

Atmospheric Research (NCAR)

1850 Table Mesa Drive

P.O. Box 3000

Boulder, CO 80307

Mr. Mike Papillo

IBM-FSD

22 Firstfield Road

Gaithersburg, MD 20879

Mr. James Park

National Bureau of Standards

Room A216, Technology Bldg.

Washington, D.C. 20234

Mr. Jack Petruzelli

USAF Rome Air Development Center

RADC/IRAP

Griffiss AFB, NY 13441

Mr. William Poland

NASA/Goddard Space Flight Center

Code 730.4

Greenbelt, MD 20771

Mr. C. Noel Proudfoot

Eastman Kodak Company

1600 Lake Avenue

Rochester, NY 14650

Dr. John Riganati

Chief, System Components Division

Institute for Computer Sciences and

Technology

National Bureau of Standards

Room A219, Technology Bldg.

Washington, D.C. 20234

224
Mr. Howard Sabrin

National Institutes of Health

DCRT/CSL

Building 12A, Room 2023

Bethesda, MD 20205

Mr. Pat Savage

Shell Oil Company

P.O. Box 481

Houston, TX 77001

Mr. Philip Scheinert

Burroughs Corporation

5411 N. Lindero Canyon Rd.

Westlake ViUage, CA 91362

Mr. Delbert Shoemaker

13461 Fowke Lane

Woodbridge, VA 22192

Mr. Charles Smith

Digital Equipment Corp.

Main Street - MS ML03-6/E94

Maynard, MA 01754

Mr. Peter Sparics

Library of Congress

Preservation Office

LMG 21

Washington, D.C. 20540

Dr. Loins Spruijt

Optical Media Laboratory (OML)

Emmasingel

Building EHl, P.O. Box 218

Eindhoven, The Netherlands

225
Mr. Richard Steinbrenner

Bell Telephone Labs

25 Lindsley Drive

Morristown, NJ 07960

Mr. Mark Strickler

Social Security Administration

6401 Security Blvdo, Room 572 NCC

Baltimore, MD 21235

Mr. Surachai Suthasinekul

National Library of Medicine

8600 Rockville Pike

Bethesda, MD 20209

Dr. Geoi^e Thoma

National Library of Medicine

8600 RockviUe Pike

Bethesda, MD 20209

Dr. Jack Tomlinson

Bell Laboratories

555 Union Blvd.

AUentown, PA 18103

Mr. Yoshito Tsunoda

Central Research Laboratory

Hitachi Ltd.

1-280 Higashikoigakubo

Kokubunji, Tokyo, Japan

Mr. William Tucker

IBM-FSD

18100 Frederick Pike

Gaithersburg, MD 20879

226
Mr. James Upperman

National Bureau of Standards

Room A265, Technology Bldg.

Washington, D.C. 20234

Dr. Jan Verhoeven

Optical Media Laboratory (OML)

Emmasingel

Building EHl, P.O. Box 218

Eindhoven, The Netherlands

Dr. Gerry Walter

Planning Research Corporation

Government Information Systems

Image Data Systems Res. Lab.

1500 Planning Research Drive

McLean, VA 22102

Mr. Donald Willis

Library of Congress

Cataloging Distribution Service

LA-G1025

Washington, D.C. 20541

Mr. Tomio Yoshida

Central Research Lab. of

Matsushita Electric

Industrial Company, Ltd.

3-15 Yagumo-Nakamachi Moriguchi

Osaka 570, Japan

Mr. Joseph Zajaczkowski

Sperry Corporation

Computer Systems

P.O. Box 500

Blue BeU, PA 19424-0001

* U.S. GOVERNMENT PRINTING OFFICE: 1984-420-997:77

227
NBS-n4A (REV. 2-8C) U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

PUBLICATION OR

REPORT NO,

NBS SP 500-111

2. Performing Organ, Report No. 3. Publication Date

April 1984

4. TITLE AND SUBTITLE Computer Science and Technology:

Proceedings of the National Bureau of Standards/National Security Agency Workshop

on Standardization Issues for Optical Digital Data Disk (OD^) Technology

(Held at the National Bureau of Standards, Gaithersburg , MD, June 1-3, 1983)

5. AUTHOR(S)

Jean B. Freedman, Editor

6. PERFORMING ORGANIZATION (If joint or other tlian NBS. see instructions)

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

8. Type of Report & Period Covered

Final

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State. ZIP)

National Bureau of Standards

Department of Commerce

Washington, DC 20234

National Security Agency

Department of Defense

Ft. George G. Meade, MD 20755

10. SUPPLEMENTARY NOTES

Library of Congress Catalog Card Number: 84-601025

Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. A,BSTRACT ( A 200-word or less factual summary of most significant information. If document includes a si gnificant

bi bliography or literature survey, mention it here}

This report constitutes the proceedings of the National Bureau of Standards/National Security Agency

jointly-sponsored Workshop on Standardization Issues for Optical Digital Data Disk (OD-^) Technology, held

in Gaithersburg, Maryland, June 1-3, 1983. The objective of this workshop is to promote discussion and

interchange among current and potential OD-^ users and suppliers, regarding the prospects for OD^ data

interchange standardization.

The workshop presentations include definitions of the physical, dimensional, optoelectrical , quality

and data transfer characteristics of OD media, as related to the drive performance. A range of OD-" applications and their standards' requirements are also described. The various methods currently used

for estimating media life expectancies and the potential for standardized terminologies and procedures

for such assessments are discussed.

Many workshop participants noted that there were numerous complexities associated with OD-^ data

interchange among systems. Data interchange parameters include the optical media sizes, their reflection and transmission characteristics, error detection and correction schemes, and numerous other

parameters that are incorporated in the functional design of OD'^ media and systems.

The participants also noted the timeliness and importance of OD^ data interchange standardization

activities and gave priority to the development of an optical digital data disk lexicon. Many of the

workshop participants also expressed an immediate need for standardized test and evaluation procedures

for OD-^ media responses, life expectancies, and environmental requirements.

12. KEY WORDS fS/x to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons)

archival storage; cartridge; computer storage media; data interchange; data transfer

interfaces; media life expectancy; optical digital data disk (OD"^) ; optical disk document scan applications; optical disk mass storage system applications; optical disk

13. AVAILABILITY systems; standardization.

Unl imited

I I For Official Distribution. Do Not Release to NTIS

Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402.

Order From National Technical Information Service (NTIS), Springfield, VA. 2216 I

14. NO. OF

PRINTED PAGES

238

15. Price

USCOMM-DC 6043-P80
ANNOUNCEMENT OF NEW PUBLICATIONS ON

COMPUTER SCIENCE & TECHNOLOGY

Superintendent of Documents,

Government Printing Office,

Washington, DC 20402

Dear Sir:

Please add my name to the announcement list of new publications to be issued in the

series: National Bureau of Standards Special Publication 500-.

Name

Company

Address

City State Zip Code

(Nolincation key N-S03)

NBS TECHNICAL PUBLICATIONS

PERIODICALS

JOURNAL OF RESEARCH—The Journal of Research of the National Bureau of Standards reports NBS research and develop- ment in those disciplines of the physical and engineering sciences in which the Bureau is active. These include physics, chemistry,

engineering, mathematics, and computer sciences. Papers cover a broad range of subjects, with major emphasis on measurement

methodology and the basic technology underlying standardization. Also included from time to lime are survey articles on topics

closely related to the Bureau's technical and scientific programs. As a special service to subscribers each issue contains complete

citations to all recent Bureau publications in both NBS and non- NBS media. Issued six limes a year. Annual subscription: domestic

$18; foreign $22.50. Single copy, $5.50 domestic; $6.90 foreign.

NONPERIODICALS

Monographs—Major contributions to the technical literature on

various subjects related to the Bureau's scientific and technical activities. Handbooks—Recommended codes of engineering and industrial practice (including safety codes) developed in cooperation with in- terested industries, professional organizations, and regulatory

bodies. Special Publications—Include proceedings of conferences sponsored by NBS, NBS annual reports, and other special publications

appropriate to this grouping such as wall charts, pocket cards, and

bibliographies.

Applied Mathematics Series—Mathematical tables, manuals, and

studies of special interest to physicists, engineers, chemists,

biologists, mathematicians, computer programmers, and others engaged in scientific and technical work.

National Standard Reference Data Series—Provides quantitative data on the physical and chemical properties of materials, compiled from the world's literature and critically evaluated. Developed under a worldwide program coordinated by NBS under

the authority of the National Standard Data Act (Public Law

90-396).

NOTE: The principal publication outlet for the foregoing data is the Journal of Physical and Chemical Reference Data (JPCRD)

published quarterly for NBS by the American Chemical Society

(ACS) and the American Institute of Physics (AlP). Subscriptions,

reprints, and supplements available from ACS, 1 155 Sixteenth St., NW, Washington, DC 20056.

Building Science Series—Disseminates technical I'-formation developed at the Bureau on building materials, components,

systems, and whole structures. The series presents research results,

lest methods, and performance criteria related to the structural and

environmental functions and the durability and safety characteristics of building elements and systems.

Technical Notes—Studies or reports which are complete in themselves but restrictive in their treatment of a subject. Analogous to monographs but not so comprehensive in scope or definitive in treatment of the subject area. Often serve as a vehicle for final reports of work performed at NBS under the sponsorship of other government agencies.

Voluntary Product Standards—Developed under procedures

published by the Department of Commerce in Part 10, Title 15, of

the Code of Federal Regulations. The standards establish nationally recognized requirements for products, and provide all concerned interests with a basis for common understanding of the

characteristics of the products. NBS administers this program as a supplement to the activities of the private sector standardizing

organizations. Consumer Information Series—Practical information, based on NBS research and experience, covering areas of interest to the con- sumer. Easily understandable language and illustrations provide

useful background knowledge for shopping in today's tech- nological marketplace. Order the above NBS puhlicaiions from: Superiniendeni oj Documents. Government Printing Office, Washington. DC 20402. Order the following NBS publications—FIPS and NBSIR's—from

the National Technical Information Service , Springfield. VA 22161

.

Federal Information Processing Standards Publications (FIPS

ptIB)—Publications in this series collectively constitute the Federal Information Processing Standards Register. The Register

serves as the official source of information in the Federal Govern- ment regarding standards issued by NBS pursuant to the Federal Property and Administrative Services Act of 1949 as amended.

Public Law 89-306 (79 Stat. 1127), and as implemented by Executive Order 11717(38 FR 1 23 1 5, dated May II, 1973) and Part 6 of Title 15 CFR (Code of Federal Regulations).

NBS Interagency Reports (NBSIR)—A special series of interim or

final reports on work performed by NBS for outside sponsors

(both government and non-government). In general, initial dis- tribution is handled by the sponsor; public distribution is by the National Technical Information Service , Springfield, VA 22161,

in paper copy or microfiche form.
U.S. Department of Commerce

National Bureau of Standards

Washington, D.C. 20234

Official Business

Penalty for Private Use $300

I