Path: utzoo!attcan!uunet!lll-winken!ames!pasteur!ucbvax!hplabs!nsc!taux01!cyosta
From: cyosta@taux01.UUCP ( Yossie Silverman )
Newsgroups: comp.sys.mac
Subject: Re: Sys. 6.02 and Dove upgrades
Message-ID: <1196@taux01.UUCP>
Date: 1 Mar 89 12:14:52 GMT
References: <12372@dartvax.Dartmouth.EDU>
Reply-To: cyosta%taux01@nsc.COM ( Yossie Silverman )
Organization: National Semiconductor (IC) Ltd, Israel
Lines: 43

In article <12372@dartvax.Dartmouth.EDU> thomas@eleazar.dartmouth.edu (Thomas Summerall) writes:
.A friend of mine upgraded his Mac 512ke to 1 megabyte and gave it a SCSI port
.with the DOVE upgrade.  He is now running on system 6.02 even though he is
.still using the old ROMs found in the 512ke.  Everything seems to work
.fine but his Everex hard disk.  It won't boot from startup although it can
.be accessed with no problem from a floppy.  You can even switch the
.system to the hard disk by command-option-clicking the finder on the HD.
.
.This means that he can't have inits on the HD and other problems, many of which
.he probably has yet to discover.
.
.Is this a Dove problem, a SCSI address problem or a system 6.02 problem?
.
.Any help would be greatly appreciated...
.
.Thanks,
.Thomas Summerall
.thomas@eleazar.dartmouth.edu


A hardware hacker friend of mine claims that there is no way that the
Everex drives will work with a Dove SCSI upgrade (I have one, but I 
got a Jasmine drive).  The reason is that Dove recognizes SCSI requests
by looking at the address lines that go into the ROMs and spotting the
appropriate addresses for the toolbox SCSI calls.  What this means is that
any disk driver which does NOT use the toolbox calls will NOT work with
the Dove upgrade.  Everex is supposedly one of these drivers.  There are
upgrades which also sit on the ROM but recognize SCSI requests in a different
manner (something about checking if the bus is reading or writting and
looking at the addresses to which it is writting, the check itself is very
tricky as the R/W lines never get as far as the ROMs!).  If your friend
cannot get rid of his Everex and get a drive that works with the Dove 
upgrade (I believe MOST drives will) than maybe he should consider getting
a new upgrade that does things in a smarter fashion (like the one described
above, whoes name I don't know).

- Yossie

-- 
Yossie Silverman                                   What did the Caspian sea?
National Semiconductor Ltd. (Israel)				- Saki
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