Path: utzoo!attcan!uunet!jarthur!usc!apple!lsr
From: lsr@Apple.COM (Larry Rosenstein)
Newsgroups: comp.sys.mac.misc
Subject: Re: II->IIfx upgrade (Yayyy!) and some strange happenings
Message-ID: <9436@goofy.Apple.COM>
Date: 26 Jul 90 17:32:19 GMT
References: <1199@kosman.UUCP> <43345@apple.Apple.COM>
Organization: Apple Computer, Inc.
Lines: 20

In article <43345@apple.Apple.COM> austing@Apple.COM (Glenn L. Austin) writes:
>
>The SCSI driver in 6.0.4 and previous calculated the partition checksum
>incorrectly (and didn't care if it was wrong!).  The 6.0.5 driver calculates
>it correctly (according to the engineers) and won't mount a drive with a
>bad partition table.  I don't know why nobody said anything, I just work

See Tech Note 258.  It says that the ROM boot code in early machines (e.g.,
Mac II) failed to compute the checksum at all, but that this bug has been
fixed in later machines (e.g., Mac IIfx).  So drives with bad checksums
would mount on machines with the bug but not on recent machines.

I wouldn't have thought that installing just 6.0.5 would fix this; you would
have to install a newer version of the driver with the correct checksum.

-- 
		 Larry Rosenstein,  Object Specialist
 Apple Computer, Inc.  20525 Mariani Ave, MS 46-B  Cupertino, CA 95014
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