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- From: roy@mchip00.med.nyu.edu (Roy Smith)
- Newsgroups: comp.sys.sgi
- Subject: Re: Hard drives...
- Message-ID: <1hr2viINNq25@calvin.NYU.EDU>
- Date: 30 Dec 92 02:53:38 GMT
- References: <34820@adm.brl.mil>
- Organization: New York University, School of Medicine
- Lines: 38
- NNTP-Posting-Host: mchip00.med.nyu.edu
-
- sgi.com!pdi!shoshana@BRL.MIL (Shoshana Abrass) writes:
- > With the sgi's, every time we attach a new disk drive we run
- > the risk of encountering scsi bus errors, timeouts, etc. When
- > we get above four scsi devices, we need to start messing around
- > with cables - a few inches in cable length can make all the
- > difference. We've never had this problem on the macs.
-
- Can't say I agree with your Mac experience. I've always had trouble
- with any more than about two SCSI devices on a Mac SCSI bus. We can usually
- manage to get 4 or so working by being very careful to use the shortest
- cables we can get, but it's often a crapshoot as to whether it will work or
- not. I once had to put 6 CD-ROM drives (and an internal hard disk) on an
- SE/30 file server. We banged our heads against the wall for weeks on that
- one, including fighting with Apple tech support on the phone for what seemed
- like forever. Our dealer tried swapping CPU boards, CD-ROM drive guts, etc,
- and eventually we ended up building a bus that had 1 FX (black) terminator
- at the end and a second FX terminator *in the middle of the bus*, plus of
- course the internal termination at the CPU end. This was on advice from
- somewhere deep inside Apple engineering, and I never heard a good
- explanation of why it worked (yes, I know it violates specs), but amazingly
- enough, it works reliably. Without that extra feed-through terminator, we
- could never get more than about 4 drives on the bus before it started to
- flake out (with all Apple drives, cables, etc).
-
- On the other hand, we've got this twin-tower SGI box that only works
- because SGI field service removed the top two sections of the SCSI tower,
- and which we're unable to plug any external devices into at all. Feh!
-
- As far as I'm concerned, SCSI means Some Crappy Stupid Interface. I
- guess it beats SMD, but it sure doesn't live up the the wonderful promises
- it made (not to mention the random connector confusion; I know of 3 commonly
- used connectors, and I havn't even mentioned the wierdo PowerBook SCSI
- connector, but I guess that's understandable).
- --
- Roy Smith <roy@nyu.edu>
- Hippocrates Project, Department of Microbiology, Coles 202
- NYU School of Medicine, 550 First Avenue, New York, NY 10016
- "This never happened to Bart Simpson."
-