Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!purdue!decwrl!shelby!neon!kaufman
From: kaufman@neon.Stanford.EDU (Marc T. Kaufman)
Newsgroups: comp.sys.mac
Subject: Re: Share SCSI drive?
Message-ID: <11060@neon.Stanford.EDU>
Date: 12 Aug 89 06:57:21 GMT
References: <10697@boulder.Colorado.EDU>
Sender: Marc T. Kaufman 
Reply-To: kaufman@Neon.Stanford.EDU (Marc T. Kaufman)
Organization: Stanford University, Computer Science Dept.
Lines: 24

In article <10697@boulder.Colorado.EDU> kuo@tramp.Colorado.EDU (Andy Y.A. Kuo) writes:

>I recently read about someone successfully make two Mac share one SCSI
>hard drive without any partition.

Not without special software.  The standard SCSI driver automaticly assigns
the Mac as device 7, and there can be only one device 7 on a bus.

>He also said that by partitioning the hard drive, he was able to 
>make a AppleIIGS(ProDOS) use one partition while the Mac use the other
>partition on the same drive without any problem. (he didn't mention IBM)

Only if the drive is physically moved between the two machines (not
connected to both simultaneously).

>My problem is, how is this possible, why would the drive allow that?
>Will this damage the hardware?

No, it won't damage the hardware -- SCSI is designed to allow just that.
However, it won't work with the Apple supplied SCSI manager, because the
default manager does not perform the Bus Arbitration phase, and so will
probably mess up a transfer from the other computer at some point.

Marc Kaufman (kaufman@Neon.stanford.EDU)