Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!apple!agate!shelby!neon!michaelg
From: michaelg@Neon.Stanford.EDU (Michael Greenwald)
Newsgroups: comp.sys.mac.system
Subject: Re: Dove MacSnap Memory upgrade vs. Hard Disks
Message-ID: <1990Nov28.002059.4447@Neon.Stanford.EDU>
Date: 28 Nov 90 00:20:59 GMT
References: <1990Nov26.222812.25166@Neon.Stanford.EDU> <1990Nov27.201121.27167@scion.CS.ORST.EDU>
Distribution: comp
Organization: Computer Science Department, Stanford University
Lines: 24

boerned@mist.CS.ORST.EDU (Dan Boerner) writes:

>I had this same problem a few years back when I bought a 2meg Dove memory
>board and Dove SCSI board for my 512KE.  If I remember right there was
>a fix for the Dove SCSI board that I got from Dove.  It consisted of a
>little socket thingy (I can't remember what it was called) that plugged
>between one the Mac ROMs and the Dove SCSI daugher board.  This fixed my
>problem completely.  Call Dove and ask for it.

>Hope this helped,
>Dan

Actually I did this much earlier.  In my original message I thought I
described how I attached the jumper between the SCSI board and the
Dove daughter board.  This was necessary to even >mount< the disk.

The problem I >was< having (note past tense - someone helped me solve
it last night) was that the system would hang forever.  It turned out
that there were timing problems in Dove's SCSI arbitration, so the MAC
was convinced that someone else took control of the SCSI bus and would
hang forever.  The fix is to patch the system code to always assume
that the Mac wins the arbitration (assuming you have no SCSI devices
that *do* actually want to take control - I don't).  I haven't had a
problem since then.