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From: dyer@spdcc.COM (Steve Dyer)
Newsgroups: comp.sys.ibm.pc.rt
Subject: What is "differential" SCSI?
Message-ID: <509@ursa-major.SPDCC.COM>
Date: 8 Nov 89 08:51:55 GMT
References: <9037@spool.cs.wisc.edu> <1989Nov6.192632.9113@arnor.uucp> <496@ursa-major.SPDCC.COM> <469@siswat.UUCP>
Reply-To: dyer@ursa-major.spdcc.COM (Steve Dyer)
Organization: S.P. Dyer Computer Consulting, Cambridge MA
Lines: 25

In article <469@siswat.UUCP> buck@siswat.UUCP (A. Lester Buck) writes:
>All I know is that I was configuring some RTs for resale by a client.  I had
>written SCSI drivers for various tape devices, so having the extra slot
>filled by the IBM streamer seemed like a waste.  I called the local Cipher
>distributor asking for a SCSI streamer, but unfortunately no one (at that
>point) had a 1/4" drive with a differential SCSI interface (thanks IBM!),

Can someone here tell me what "differential SCSI" is, and how it's
different from the SCSI I'm used to on Macs, {DEC,VAX}station 3100s,
Adaptec 1542s, and Suns?

We've got lots of IBM Athens 400mb drives, some of which would be nice to
attach to our {DEC,VAX}station 3100s, and some people are asking about
attaching DEC RZ53s to the IBM SCSI controller (yes, I know that the
AOS 4.3 SCSI driver seems wedded to the weirdness of the Athens drive--
I'm concerned with things I have no control over like hardware
incompatibility, and not with presumably tractable driver problems.)

Is there really an electrical problem here?  Can someone accurately
characterize the issue as a compatibility problem or not?

-- 
Steve Dyer
dyer@ursa-major.spdcc.com aka {ima,harvard,rayssd,linus,m2c}!spdcc!dyer
dyer@arktouros.mit.edu, dyer@hstbme.mit.edu