From: ncpmont@angelo.amd.com (Mark Montgomery)
Subject: PhotoCD and Sony drives
Organization: Advanced Micro Devices, Santa Clara, CA
Distribution: usa
Date: Thu, 15 Oct 1992 22:36:45 GMT

It seems that many of you are stuck on the horns of the same
dilemma as I when it comes to picking a drive to buy for use with
Kodak`s new PhotoCD technology - Should I buy a drive now that's
capable of single session and HOPE that it can be upgraded later
or should I wait and buy a true multi session capable drive.

As of this morning, Kodak is stating that there are NO multi session
capable drives on the market.  The one possible exception is the new
Apple 300i which is, I believe, a repackaged Sony CDU-561.  They do
endorse several current drives for single session use - the Toshiba
3301, the Sony 535/6205 and the NEC CDR-73 (absolutely NOT the
CDR-74/84's).  They also said that the Philips/Magnavox CDD-461
w/ device driver 1.03 or later will work single session.  Their
literature states that they are working with Philips, Pioneer,
Sony and Toshiba and that all 4 of these Mfg's will have multi capable
drives available "real soon now".  I suspect that some of the delay is
due to things like 'Marketing Stance' and the desire by all parties to
get the "KODAK PhotoCD Approved" sticker on their products (has anyone
noticed the barrage of Kodak ads in the media in the last week or two?).

My guess is that one of the best bets will be the Sony CDU-561 as they
are currently working with Apple on this and similar applications and
I have been pestering the local Sony people for info on this drive and
schedules for it's release.  The last word I received was that data
sheets would be available around the end of October, drives would be
shipping to VAR's and OEM's in late November & December and finally to
retail channels after the first of next year.  I think I'm gonna wait
but that's sure going to stretch my patience.  The following is a
copy (sort of) of the info I have on the Sony 561 so if you're not
interested you'll probably want to page on by.  I must also disclaim
any affiliation with Sony and that I am propagating this info without
permission from Sony only because I thought some of you would find it
informative.


COPIED FAIRLY FAITHFULLY FROM SONY CDU-561 PRELIMINARY DATA SHEET
=================================================================

First the Hype.
---------------

Always Leading the Industry - Now Double-Speed CDU561

Sony once again sets the standard in CD-ROM performance.  The new
CDU561 offers a 100% increase in the sustained data transfer rate
and a remarkably reduced access time of 280ms (average).  Reliability
has also been improbved, providing the MTBF of 25,000 POH (duty 100%)
or 50,000 POH (duty 25%), as well as extra protection against dust.
Combining speed with reliability with enhanced audio capability in a
SCSI embedded standard 5.25" half-height drive, the CDU561 is ideal
for a multitude of built-in applications, ranging from workstation's
OS server to multimedia data storage.

A New Level of Performance

The sustained data transfer rate has been doubled to 300KB/s by the
adoption of an FG servo-controlled twin magnet motor rotated at double
the speed of our conventional models.  The double-speed motor also
combines with a significantly reduced average access time of 280ms.
As a further contribution to high-speed operation, the CDU561 enables
burst transfer of 4MB/s (synchronous) or 2.5MB/s (asynchronous).

256KB Buffer Memory

To allow efficient use of the SCSI bus, the SCSI controller of the
CDU561 supports SCSI-2 level commands.  It also incorporates a 256KB
ring buffer for sequential data read at the transfer rate of the host
computer.

Added Audio Flexibility

The CDU561 can read CD-ROM, CD-ROM XA, CD-DA, CD-I and CD-I bridge
disks and is equipped with headphone and line out connectors for audio.
Output levels and playback modes are software controlled from the
computer.  With the CDU561, moreover, CD digital audio data with the
subcode R to W channels can be transferred via the SCSI bus to the
audio interface of the host computer or some other storage device in
the system.

Dust-Proof Design

The disc slot is provided with double shutters to eliminate dust.  The
cabinet has no holes and openings other than the air inlet and outlet
so that the air flow inside the cabinet can be controlled to minimize
the dust entering into the optical pick-up area.  The pick-up features
an automatic lens cleaner that wipes the dust off the objective lens
every time the caddy is ejected.

3-Way Eject

Disc ejection can be controlled either from the host computer or on
the CDU561's front panel.  Emergency eject is also possible.

NOW FOR THE GOOD STUFF !!
=========================

Specifications

Data transfer rate:
	sustained		150KB/s (Mode 1, normal speed, typical)
				300KB/s (Mode 1, double speed, typical)
	burst			2.5MB/s (Mode 1&2, asynchronous)
				4.0MB/s (Mode 1&2, synchronous)

Access time:
	Full stroke		550 ms (normal speed, typical)
				520 ms (double speed, typical)
	Average			350 ms (normal speed, typical)
				280 ms (double speed, typical)

Read Error Rate:		1 block/10^15 bits (norm spd, ECC on)
				1 block/10^12 bits (doubl spd, ECC on)
				1 block/10^12 bits (norm spd, ECC off)
				1 block/10^9 bits (doubl spd, ECC off)

MTBF:				25,000 POH (duty 100%)

Host Interface:			SCSI-2

Audio Outputs:
	Line output		0.7V/47Kohms. Molex 5043-04A or equiv
	Headphone output	0.5V/32ohms. Stereo minijack

Operating Mount			Horizontal or vertical

The rest of the specs re: power and environmental are just like all
other drives.

WHEW!!
			Regards,	Mark