roy@alanine.phri.nyu.edu (Roy Smith) (11/27/90)
We're planning on putting together a large CD-ROM AppleShare
server. We're currently looking at something like a SE-30 with an internal
Apple 80 or 160 Mbyte drive and 6 Apple CD-ROM drives (I originally speced
a Quantum-105 and Toshiba CD drives, but artificial contraints forced an
all-Apple system). Has anybody ever tried having 7 SCSI disks on a Mac?
It's supposed to be possible, but I know all sorts of strange things have
been known to happen on SCSI busses with more than a couple of devices.
--
Roy Smith, Public Health Research Institute
455 First Avenue, New York, NY 10016
roy@alanine.phri.nyu.edu -OR- {att,cmcl2,rutgers,hombre}!phri!roy
"Arcane? Did you say arcane? It wouldn't be Unix if it wasn't arcane!"Patrick.Hayes@cediag.bull.fr (Patrick Hayes) (11/27/90)
Well, my scsi bus isn't maxed out yet, but I do have a word or two to say. My A/UX Mac II has: Scid 0: Micropolis 1578 external 330 Mbyte HD Scid 1: Apple Quantum internal80 Mbyte HD Scid 2: Microtech Syquest 44 Mbyte removable Scid 3: Archive 60EP/150EP DC600 (A/UX only) Scid 4: Apple CD-ROM I had no end of problems once I connected the CD-ROM, until I opened it up and noticed that Apple had miscabled the connectors. Normally cabled SCSI drives have cables that go from Scsi in -> Scsi device -> Scsi out. The Apple drive violates the Scsi bus by using Scsi in -> Scsi out -> Scsi device. Once I cut off one the connectors by cutting the cable between the two connectors and turning the CD-ROM into an endpoint-only device I stopped having corrupted filesystems. When I find someone in france selling 50 point ribbon cable, I'll try to fix the drive and turn it back into a device I can put anywhere on the bus. Given my experience with the Apple CD-ROM, I can't recommend it to anyone else until Apple recables them correctly. I'm fairly angry at Apple for selling products which are as badly designed as this, If anyone could justify this behavior, other than saving 2 cents, I'd like to hear it. Pat -- +-------------------------------+-----------------------------------------+ | Patrick Hayes | EMail : Patrick.Hayes@cediag.bull.fr | | BULL CEDIAG | or hayes@bull.fr | | 68, Route de Versailles | or ...!mcvax!inria!bullfr!hayes | | F-78430 Louveciennes FRANCE | Tel : (33 1) 39 02 49 55 | +-------------------------------+-----------------------------------------+
russotto@eng.umd.edu (Matthew T. Russotto) (11/28/90)
In article <PATRICK.HAYES.90Nov27133812@cediag.cediag.bull.fr> Patrick.Hayes@cediag.bull.fr (Patrick Hayes) writes: >Well, my scsi bus isn't maxed out yet, but I do have a word or two to say. >My A/UX Mac II has: >Scid 0: Micropolis 1578 external 330 Mbyte HD >Scid 1: Apple Quantum internal80 Mbyte HD >Scid 2: Microtech Syquest 44 Mbyte removable >Scid 3: Archive 60EP/150EP DC600 (A/UX only) >Scid 4: Apple CD-ROM >I had no end of problems once I connected the CD-ROM, until I opened it up and >noticed that Apple had miscabled the connectors. Normally cabled SCSI drives >have cables that go from Scsi in -> Scsi device -> Scsi out. The Apple drive >violates the Scsi bus by using Scsi in -> Scsi out -> Scsi device. Once I cut >off one the connectors by cutting the cable between the two connectors and >turning the CD-ROM into an endpoint-only device I stopped having corrupted >filesystems. When I find someone in france selling 50 point ribbon cable, I'll >try to fix the drive and turn it back into a device I can put anywhere on the >bus. > >Given my experience with the Apple CD-ROM, I can't recommend it to anyone else >until Apple recables them correctly. > >I'm fairly angry at Apple for selling products which are as badly designed as >this, If anyone could justify this behavior, other than saving 2 cents, I'd >like to hear it. My early Apple CD ROM (w/fan) has the cable wired properly. Is yourse a REALLY early one, or is it a newer one without the fan? -- Matthew T. Russotto russotto@eng.umd.edu russotto@wam.umd.edu .sig under construction, like the rest of this campus.
cfj@isc.intel.com (Charlie Johnson) (12/01/90)
According to the SCSI standard, what you describe is not actually non-conforming to the standard as long as the stub created inside the CD rom drive is less than .1 meters (4 inches). -- Charles Johnson Intel Corporation, Supercomputer Systems Division 15201 NW Greenbrier Pkwy Beaverton, OR 97006 phone: (503)629-7605 email: cfj@isc.intel.com