[comp.ivideodisc] WORM Drives

careyk@uhunix1.uhcc.Hawaii.Edu (Carey Kinoshita) (06/19/91)

I was wondering if there is an industry standard format 
for WORM (Write Once Read Many) drives.  Or is there a
dominant format which most vendors use?  I have noticed
that some of the new Magneto-Optical Drives can also
read WORM discs, I was wondering what WORM format are
they capable of reading.  I am currently in the midst of
choosing which WORM drive to purchase for my department
since my company needs a permanent non-erasable backup 
device.  Thanks.

eric@mcrware.UUCP (Eric Miller) (06/19/91)

In article <13525@uhccux.uhcc.Hawaii.Edu> careyk@uhunix1.uhcc.Hawaii.Edu (Carey Kinoshita) writes:
>I was wondering if there is an industry standard format 
>for WORM (Write Once Read Many) drives.  Or is there a
>dominant format which most vendors use?

The document which describes Magneto-Optical and Write Once Discs is called
the Orange Book.  The O.B. is split into the distinct sections; one for
MO and one for WO.  I have heard of relatively little in the way of cross-
compatibility between the systems.

One important element that the Orange Book does not address, however, is the
issue of File Systems on the discs.  There is currently an experts group
which is trying to define an ISO standard for a WO File System.  The output
of this effort will really define compatibility for WO systems.

When you look at WO drives, consider also the question of whether you will
write the entire disc in one session, or whether you need the ability to
update files periodically.  If you will write the disc in one session, then
you can take advantage of current CD-ROM / CD-I file systems.  If you need
to have incremental updates, you need a more advanced file system like that
being designed now.

The only WORM drive that I have had direct experience with is the Yamaha PDS
system.  We use it to make CDDA / CD-ROM / CD-I discs in one-session writes.
It has been very reliable.

If you need more information on the Orange Book, File Systems or Yamaha PDS
Systems, please contact me directly.

Eric Miller
Manager, New Media Systems
Microware Systems Corp.
Des Moines, IA 50325
515-224-1929
uucp!mcrware!eric