Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!brutus.cs.uiuc.edu!apple!mattd
From: mattd@Apple.COM (Matt Deatherage)
Newsgroups: comp.sys.apple
Subject: Re: Disk Strangeness...
Message-ID: <36422@apple.Apple.COM>
Date: 13 Nov 89 14:45:06 GMT
References: <8911121802.AA24627@trout.nosc.mil>
Organization: Apple Computer Inc, Cupertino, CA
Lines: 46

In article <8911121802.AA24627@trout.nosc.mil> chaosboss@pro-lep.cts.com (Circuit Breaker) writes:
>My system consists has a Unidisk 3.5, and 2.25 Meg of RAM w/RAMKeeper.  I have
>768k dedicated to a ROMDisk and use it for the boot drive (10 second boot)
>
>Anybody else had this happen to them?  I play it reall safe these days when
>using SHRConvert and Sound Studio.
>
>BTW:  After the first time this happened, I write-protected ALL my disks
>(isn't paranoia great?)  but that didn't help at all.  It actually wrote to a
>write protected disk!
>
>UUCP: crash!pro-lep!chaosboss
>ARPA: crash!pro-lep!chaosboss@nosc.mil
>INET: chaosboss@pro-lep.cts.com

Sorry, but it didn't write to a write-protected disk unless your hardware is
broken.  What could have happened, though, is that the disk cache got corrupted
and reads from the drive erroneously read bad cache blocks.  If this were the
case, then dropping into ProDOS 8 or just rebooting should magically "fix" the
disk.  But what you describe isn't literally possible with correctly-working
hardware.

BTW, I have UniDisk 3.5 drives at home (exclusively) and have seen *none* of
the problems like this that are often posted to this newsgroup.  May I suggest
that those with problems like this check two things:

1)  They really have UniDisk 3.5 drives (they're usually white, and the manual
eject hole is below the eject button, and they're made by Apple) and not some
other drive (I've known people who thought their Central Point drives were
"UniDisk 3.5" because that's what some program told them.)

2)  If using a IIgs, make sure the UniDisk 3.5 Driver is both installed and
activated in the */System/Drivers folder.  Some people liked to deactivate it
under 4.0 because they didn't like the noise, and these symptoms are exactly
the kinds of things which might result (the drive not noticing switched disks).


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