Path: utzoo!attcan!uunet!fernwood!portal!apple!bionet!arisia!sanders.parc@xerox.com
From: sanders.parc@xerox.com
Newsgroups: comp.sys.mac.hardware
Subject: IIfx vs the scanner - scanner wins!
Summary: I don't always need that black thingy?
Keywords: SCSI Microtek terminator
Message-ID: <14862@arisia.Xerox.COM>
Date: 12 Dec 90 02:25:27 GMT
Sender: news@arisia.Xerox.COM
Reply-To: sanders.parc@xerox.com
Organization: Xerox PARC
Lines: 41

Todays Macintosh support headache:

Mac IIfx, System 6.05, 120 Mb Seagate HD, Microtek color scanner,
  3 foot SCSI cable, black (IIfx) terminator between cable & scanner.

Suddenly, Mac has trouble booting from hard disk.  Starts to boot,
get error tones, Sad Mac, codes 0000000F 00007FFF.

Reformat HD many times.  Can't re-install system software from
locked Apple floppies.  Can boot from floppies and use HD.
Spend many hours trying to figure out what's wrong.

Give up, send Mac out to Apple dealer.  Dealer says: nothing wrong.

Bring Mac back, hook everything up, same troubles.  Get dealer tech
on-site ($$$).  Spends hours trying many things.  Won't boot from
new HD, etc.

Brainstorm: whats different between office and dealer? No scanner at
dealer.  Trying turning scanner off or on - same problem.  Finally
unplug SCSI cable at Mac end - sudden success.

Suspect SCSI address conflict.  (Try to avoid changing the SCSI
address on a Microtek color scanner - 15 minute operation!)  Anyway,
that did not solve problem.

Called Microtek 800 number.  Oops, sales, not tech support.  However,
they must have heard this problem before.  They say:

  remove the SCSI terminator

Now, theoretically we have 2 SCSI devices and only one (Mac internal)
terminator.  Heresy!  But we tried it, and it worked.

Don't try this at home, kids.  Unterminated SCSI chains on other
Macs I've known (and sworn at) have scrambled the internal HD.

Morals:
  SCSI is a *very* dark art.  Even simple setups ain't so simple.

-- Rex