Newsgroups: comp.sys.hp


There used to be a document printed by Hewlett Packard describing the
LIF format. It was titled:

                      LIF
           Logical Interchange Format

     Directory Organization & Record Format
             for Data Interchange



The part number was 5955-2676 and it was printed January, 1982. You might
still be able to order it from HP or find someone locally that could copy
it for you.
Here's a quick description that might help users trying to read the format.

The volume format is linear. At the beginning is a volume label, followed
by a directory, then the user files.


Start of Media                                              End of Media
|                                                                      |
|                                                                      |
|             -----------------------------------------------          |
|           --|------------------------------               |          |
|         --|-|------------------           |               |          |
|       --|-|-|-----            |           |               |          |
|       | | | |    |            |           |               |          |
------------------------------------------------------------------------
|      | | | | |            |          |                  |       |    |
|      |1|2|3|4| File #1    | File #2  |  File #3         |File #4|    |
|      | | | | |            |          |                  |       |    |
|      | | | | |            |          |                  |       |    |
------------------------------------------------------------------------
   |   \       /\                                                      /
   |    -------  ------------------------------------------------------
   |       |                             |
   |       Directory                User Files
   |
   Volume label


The volume label is 128 (16 bit) words (256 bytes). With the following layout.

       WORD  (16 bits)                   CONTENTS
       ------------------------------------------------------------------
         0                      100000 OCTAL (LIF ID)
       ------------------------------------------------------------------
         1
         2              VOLUME LABEL (0-6 ASCII CHARACTERS)
         3
       ------------------------------------------------------------------
         4
         5     DIRECTORY START ADDRESS (RECORD NUMBER. USUALLY 2)
       ------------------------------------------------------------------
         6            100000 OCTAL (REQUIRED BY HP3000 SYSTEMS)
       ------------------------------------------------------------------
         7                       DUMMY (SET TO 0)
       ------------------------------------------------------------------
         8
         9               LENGTH OF DIRECTORY (IN RECORDS)
       ------------------------------------------------------------------
        10               VERSION (0 FOR NO EXTENSIONS)
       ------------------------------------------------------------------
        11                          SET TO 0
       ------------------------------------------------------------------
        12-20                 LEVEL 1 EXTENSIONS
       ------------------------------------------------------------------
        21-126    RESERVED FOR EXTENSIONS AND FUTURE USE (SET TO 0)
       ------------------------------------------------------------------
        127      RESERVED BY HP250 SYSTEMS FOR MEDIA MAINTENANCE WORD
       ------------------------------------------------------------------

If VERSION is set to 1, then the LEVEL 1 EXTENSIONS is set to:

       WORD  (16 bits)                   CONTENTS
       ------------------------------------------------------------------
        12
        13                          TRACKS PER SURFACE
       ------------------------------------------------------------------
        14
        15                         SURFACES PER MEDIUM
       ------------------------------------------------------------------
        16
        17                          SECTORS PER TRACK
       ------------------------------------------------------------------


Each directory entry is 16 (16 bit) words (32 bytes). The format is:


       WORD  (16 bits)                   CONTENTS
       ------------------------------------------------------------------
         0          |
         1          |
         2          |   FILENAME (1-10 ASCII CHARS WITH TRAILING BLANKS)
         3          |
         4          |
       ------------------------------------------------------------------
         5          |                      FILE TYPE
       ------------------------------------------------------------------
         6          |
         7          |            STARTING ADDRESS (RECORD NUMBER)
       ------------------------------------------------------------------
         8          |
         9          |               LENGTH OF FILE (IN RECORDS)
       ------------------------------------------------------------------
        10          |
        11          |             TIME OF CREATION (12 BCD DIGITS)
        12          |
       ------------------------------------------------------------------
        13          | L |                VOLUME NUMBER
       ------------------------------------------------------------------
        14          |
        15          |                   IMPLEMENTATION
       ------------------------------------------------------------------


FILE TYPE is a signed word with the following defined types:


        0 - Purged file
        1 - ASCII file
       -2 - Binary file

Other file types are dependent on the operating system.

TIME OF CREATION is 12 BCD digits is the form YYMMDDHHMMSS (Year, Month, Day,
Hour, Minute, Second). This field may contain a version number on systems
that do not use a real time clock. If the Year and Month fields are 0, then
the rest of the digits represent a version number.

L flag in VOLUME NUMBER is 0 if this is not the last volume, 1 if it is.

VOLUME NUMBER is a 14-bit unsigned number. 0 not a valid.

IMPLEMENTATION is a file type implementation specific field. It must be 0 for
any interchange file types (ie. 1 and -2). It contains information such as
load address.



The document provides more detail and should be refered to if more information
is required.

               Charlie Brett - HP Ft. Collins, CO


These comments are only my opinion and in no way represents Hewlett Packard ...
From: franks@hpuamsa.neth.hp.com (Frank Slootweg CRC)
Date: Mon, 28 Dec 1992 09:34:57 GMT
Subject: Re: When will HP supply PATCHES before they are Required?
Organization: Hewlett-Packard, The Netherlands