Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!uunet!stanford.edu!agate!darkstar!ucscb.UCSC.EDU!tmaster
From: tmaster@ucscb.UCSC.EDU (The Master)
Newsgroups: comp.sys.apple2
Subject: Multi SCSI card system..
Message-ID: <13221@darkstar.ucsc.edu>
Date: 9 Mar 91 07:53:43 GMT
Sender: usenet@darkstar.ucsc.edu
Organization: University of California, Santa Cruz; Open Access Computing
Lines: 23



  I'm curious as to the safety (contention wise) of having a system with
2 apple scsi controllers (Rev C cards) with hard drives.

 This system would be on apple ///'s, in which I have my own drivers.
The drivers make smartport calls.  Do the cards check and handle contention
if the scsi bus is already in use?  If not, does anyone have some
documented code which will handle this (Since it is using device
drivers, I can put this code in..)

 My hope is to have 2 apple ///'s and 2 scsi drives all hooked on the
same bus (I can make one scsi drive read only to one computer and the
other read only to the other computer through the device drivers to control
problems with overwrites.)  With this setup, either computer can therefor
access all the information on the two drives (therefor making it easier
to copy from one system to another).

 Also, what about DMA scsi cards?  Are they different for handling the
above situation?

	The Master
	tmaster@ucscb.ucsc.edu