Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!bbn!apple!mattd
From: mattd@Apple.COM (Matt Deatherage)
Newsgroups: comp.sys.apple
Subject: Re: GSOS expert wanted
Message-ID: <38327@apple.Apple.COM>
Date: 4 Feb 90 18:19:37 GMT
References: <4934.feeds.info-apple@pro-tcc>
Organization: Apple Computer Inc, Cupertino, CA
Lines: 31

In article <4934.feeds.info-apple@pro-tcc> lvirden@pro-tcc.cts.com (Larry Virden) writes:
>
>If ANYONE out there has a fix for this - so that File selection knows that I
>have changed disks on the Unidisk - PLEASE let me know!
>
>Larry W. Virden                 ProLine: pro-tcc!lvirden

I finally figured this one out about three weeks ago.  All of Apple's drivers
were made "restartable" when 5.0 came out, so they don't have to be reloaded
from disk when coming back from P8.  The only exception is the 5.25" driver,
which would have real design issues with restartability.

Well, the UniDisk driver doesn't restart properly.  Engineering has since
determined that on startup it converts a table of offsets to addresses, but
doesn't convert them back to offsets on a warm shutdown, so the next time it
tries to start up, it takes the old addresses as offsets, and toasts only a
few portions of the driver (like the one looking for switched disks).

If you have the 5.0 documentation, you can use a block editor to change the
beginning of the driver to not be restartable (fixing the actual problem in
restarting requires recompiling; we'll fix it on the next System Disk).  I
can't tell you how to do it now because I'm using my machine with the patched
driver on it and can't go comparing it to the original.  I'll look later,
though.

-- 
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Matt Deatherage, Apple Computer, Inc. | "The opinions represented here are
Developer Technical Support, Apple II |  not necessarily those of Apple
Group.  Personal mail only, please.   |  Computer, Inc.  Remember that."
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