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From: perry@key.COM (Perry The Cynic)
Newsgroups: comp.sys.mac.hardware
Subject: Re: CD-ROM player for both Mac and PS/2
Message-ID: <1391@key.COM>
Date: 18 Jan 90 22:02:46 GMT
References: <19715@vax5.CIT.CORNELL.EDU> <6211@internal.Apple.COM>
Reply-To: perry@arkon.key.COM (Perry The Cynic)
Distribution: comp
Organization: Key Computer Laboratories, Fremont
Lines: 51

In article <6211@internal.Apple.COM> blob@apple.com (Brian Bechtel) writes:
> In article <19715@vax5.CIT.CORNELL.EDU> st5@vax5.CIT.CORNELL.EDU writes:
> > I'm interested in getting a CD-ROM player mainly for use on the
> > Mac, but I also need to access several CDs from the PS/2.
> 
> I have a catalog from the "Bureau of Electronic Publishing" (201) 
> 857-4300, Fax (201) 857-3031.  In this catalog they list drives by Denon, 
> NEC, and Toshiba that have both IBM and Macintosh interfaces.  As I 
> understand it, all you'd need on the IBM side is a SCSI interface card, 
> cable, and software.  All you need on the Mac side is cable and software.

Yes, each of these drives will work with *either* a PC-compatible, *or*
a Mac, in the sense that (given the appropriate SCSI card for the PC, and
the right software) you can connect it to either and it will work. The
Bureau's people claim to know how, and are willing to sell you solutions.
I haven't taken them up on it (yet). Does anybody have experiences (good
or bad) with those people?

On the other hand, if you actually want to use your drive with *both*,
switching it from one to the other as desired, you'll have a lot more
problems. For one, you'll probably have to reboot both machines anytime
you make a switch, no matter how cleverly you do it. Then you need to
consider proper termination of both SCSI buses, both with and without your
CD drive on them. That should be simple if the CD drive is the only
(external) SCSI device on both machines. And then of course there's the
reliability problem of continually connecting and disconnecting devices
on your SCSI bus(es).

I suppose I could build a switchbox. It would need to connect a common
"tail" of SCSI devices to one of two "head" buses, while properly terminating
the other one. I'm not a hardware guy though - comments, anybody?

In gray theory, it should be possible to put both the PC and the Mac onto
one unified SCSI bus. I'm considering the possibility, but what I'm hearing
isn't encouraging. The Mac's SCSI implementation is said to be lacking
important features of the standard (proper arbitration, for one), and
typically each SCSI controller thinks it owns the world. It might work
if you get a PC SCSI controller than can be switched to be an ID other than
zero (your Mac internal disk, if any) and seven (the Mac). Seeing how I have
large SCSI disks on both my Mac and my PC, I'm somewhat reluctant to
experiment.

Unfortunately, the PC/Mac issue for CD ROMS is important. As of today,
about 70% of all CD ROM titles (of my random sample) seem to come with
PC retrieval software, with the remaining 30% being Mac-ish disks.  I don't
want to give up on either side. But what's a user to do? I'm not sure...
  -- perry
-- 
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Perry The Cynic (Peter Kiehtreiber)		     perry@arkon.key.com
** What good signature isn't taken yet? **	   ...!pacbell!key!perry