From: paul@hydres.uucp
Date: Tue Aug 11 1992 - 17:14:30 CDT

Ok here is the answers I got back most people were interested one wondered
why I am not using Exabyte - well thats me I don't like that much
data on a magnetic tape, and I want the data there min. fuss and agro
for up to ten years.

Here is he main stuff from someone who says this info
is not official !!

Such a device arrived in our lab a few weeks ago, and I just got around
and plugged it in. So far it works!
A few notes:
1. These devices are Write-Once, non-erasable.
   They are CD-ROM compatible: write a disk, and put it into the CD-player
   of a PC or SUN.
2. Writing software for SUN seems to be available, but I have worked with
   the PC driver software. That software has 3 main functions:
   1. Generate an ISO-9660 image from an MS-DOS filesystem, and output
      it to a file;
   2. Write a CDrom image (created by 1) to CDrom;
   3. Generate an ISO-9660 image from an MS-DOS filesystem directly
      on a CD-writable disk.
   I *think* the image in 2. might be an UFS image too but have not tried
   that yet.
3. On a CD, one can put more than one data-track. However, most readers,
   (including SUN's) cannot access anything else than the first datatrack
   as far as I know. Which means that I can write only one 'everywhere-
   readable' filesystem on a CD.
4. The writer itself can write several different kinds of tracks (audio,
   data, etc), but the PC software only writes CDroms. Being beta, that
   might change, I don't know.
5. The writer writes data at 'double speed'. Normaly, a CD reads 75 sectors
   a 2048 bytes per second. This one goes double fast, so you need to
   deliver 300 kbyte/sec continuously! I ended up tooling up a PC
   dedicated for that purpose, because that was the easy way.
   I don't think NFS can cut it because the drive, once writing, can't
   wait: if the data isn't fast enough, something goes wrong!
   On the other hand: a 550 mbyte filesystem is written in about half
   an hour, which is much faster than the time I needed to prepare the data.
6. I _think_ UFS filesystems can be written with this setup, but
   have not tried it yet.
7. I think adding data to a track might be difficult. You can't add data
   to an UFS filesystem without changing what has been written already
   (which is impossible), but it seemd there is a way to add data to an HSFS
   filesystem. I have not tried that yet.
8. You can make a CD using the procedure described in the SUN Software
   Technical Bulletin, February 1992 issue. That is what I tried and
   what I have not completed yet.
   Minor nit: the filesystem must have a size that is a multiple of
   2048 bytes for now. So, the numbers of sectors reported by format
   must be dividable by 4. No problem at all.
That is all I can think of now.
I'm not in the group that developed it; we had to buy the drive
like everybody else. This Is Not An Official Statement!
If you want to get more info, and you can't get it from the local sales
representative, try the contact I have:
        Douwe Lycklama a Nijeholt
        Philips Interactive Media Systems
        FAX +31 40 735772
I forwarded your address to him and he will send some data.

I just finished my first complete test-CD containing 525 mbyte of data
in UFS format. It works, and is currently being fsck'ed on the SUN
(sony) drive. As an experiment, I put a boot-block on it as well and that
worked too. Soo..
Geert Jan

thanks to those who expressed interest - I suggest you get in touch
with (Geert Jan de Groot)
and he'l keep you informed of futher details !

Paul Humphreys ( Postmaster ) paul@hydres.uucp
HR Wallingford
Howberry Park
Wallingford Tel: 0491-35381 X2292
Oxon Fax: 0491-32233

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