Re: CDROM Burners

[dempson@actrix.gen.nz (David Empson)]

Wayne Stewart <waynes@intergate.bc.ca> wrote:

> Brian Hammack wrote:
> 
> > Complete lack of burning software for the Apple series comes to mind.
> >
> > A CD burned, however, will work if you burn it as HFS or ISO9660.
> >
> 
> It'll work even better if you burn it in ProDOS thereby being available
> Ifor the Ie.

Only if you were burning a small amount of data.  A partitioned CD-ROM
would become unwieldy on a IIe if you had more than about two partitions
(maybe four, if the machine doesn't have a hard drive).  You wouldn't be
able to access many more than that with an original Apple SCSI card, and
you would run out of unit numbers if you went much higher with an Apple
High-Speed SCSI card.  The RamFast might allow manual switching between
enabled partitions, but it would be very clumsy to use.

The preferred solution for dealing with a lot of data for a IIe would be
to burn the CD in ISO-9660 format, and use specially written software
which handles the ISO file system itself.  I believe Apple had a package
which supported this, though I never saw it.  In any case, I expect that
ISO is simple enough that it wouldn't be hard to write custom code to
handle it.

I expect that mixing ISO and ProDOS could be achieved using the same
technique as a Mac hybrid ISO/HFS session.  This would allow the Apple
IIe to see a normal 32MB ProDOS partition, and special software on the
CD would provide access to all the data buried in the ISO part.  I don't
know of any software on the Mac which would be able to burn this
combination.

Using a multi-session CD on an Apple II is unlikely to be useful, given
the age of the CD-ROM drives which are typically used with the II
family.  Old CD-ROM drives can only see the first session, so later ones
would be ignored.

On the Mac, you can do a multi-session CD with a single HFS partition in
each session.  This appears on the desktop as a separate logical volume
for each session.  Each session is a completely self-contains HFS
volume.

An ISO disk is different: if multiple sessions are written, the computer
only mounts the last one.  Data in earlier sessions can be referenced
from the directory of later ones.

A ProDOS multi-partition CD is actually a single session, which contains
a partition table just like a hard drive.  These partitions can be
ProDOS and/or HFS, and the IIgs will happily mount all of them.  The
Mac's standard CD-ROM driver ignores all the ProDOS partitions, only
seeing the HFS ones (possibly only the first HFS partition).

An example of this is the System 6 Golden Master CD.  It has a single
session, and within that session has six ProDOS partitions, followed by
an HFS partition.

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P O Box 27-103, Wellington, New Zealand