Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site brand.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!bellcore!decvax!ittatc!dcdwest!sdcsvax!sdcrdcf!oberon!brand!weber
From: weber@brand.UUCP (Allan G. Weber)
Newsgroups: net.micro.mac
Subject: Using Mac+ SCSI port with SASI controllers
Message-ID: <187@brand.UUCP>
Date: Thu, 13-Mar-86 14:26:13 EST
Article-I.D.: brand.187
Posted: Thu Mar 13 14:26:13 1986
Date-Received: Sun, 16-Mar-86 00:43:49 EST
Distribution: na
Organization: U. of So. Calif., Los Angeles
Lines: 27

Some months ago I put together the MacSCSI hard disk interface from Fastime
using a Xebec S1410 and a Seagate ST-506 5mb disk.  It has worked reasonable
well off my 512k Mac.  When I got a Mac+ I wanted to get the S1410/ST-506
combo working off the Mac+ SCSI port, hopefully as a bootable device.  I made
a cable to go from the DB-25 SCSI connector on the back of my Mac+ to the 50
pin Berg-type connector on my Xebec controller board.  Upon trying it out,
the Mac+ never seemed to notice the disk on the SCSI port.  It would never
access it, either for booting or after booting from a floppy.

Today I called Xebec to see if they knew how to get their S1410 to work off
the Mac+ and they said that the S1410 definitly won't work on the Mac+.
They said the S1410 is SASI while the Mac+ is SCSI and they are not
compatible due to something Apple has done in their SCSI implementation.
This surprised me since the Mac+ SCSI port uses the same NCR SCSI chip for
the interface as does my Fastime MacSCSI board.  Apparently Apple has done
enough things differently in their SCSI implementation to make the port
incompatible with SASI controllers, at least when using the SCSI support
available in the Mac+ ROMs.

I would be interested in hearing from anybody who can confirm all this.
Right now I have a S1410 and a S1410A controller at home that are looking
pretty useless.

				Allan Weber
				Univ. of So. Calif.
				Arpanet: Weber%Brand@USC-ECL
				Usenet:  ...sdcrdcf!oberon!brand!weber