Newsgroups: comp.unix.i386
Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!usenet.ins.cwru.edu!neoucom!wtm
From: wtm@uhura.neoucom.EDU (Bill Mayhew)
Subject: Re: ISC won't install on 330meg ESDI
Message-ID: <1990Aug03.134202.8338@uhura.neoucom.EDU>
Keywords: ISC ESDI woes
Organization: Northeastern Ohio Universities College of Medicine
References: <260@microm.UUCP>
Date: Fri, 03 Aug 90 13:42:02 GMT

ISC seems to be a fairly close relative of AT&T 3.2.  I found that
AT&T Unix seems to have a strong prejudice against any non-Western
Digital brand HD controllers.  Unix does not use the BIOS code on
the controller due to the fact that controller BIOSes don't support
reentrancy (as a rule of thumb).  For AT&T (and perhaps ISC if they
inhereted the driver code from AT&T), this means that absolute 100%
register level compatibility is required on the HD interface card.

My system at home is a JDR 386-33 MHz cache board.  I am using a
Priam 330 megabyte drive with 1220 cylinders and a WD-1007V-SE2
floppy/hard ESDI controller.  I strapped the board to provide
sector translation to 63 sectors per track.  The sector translation
is transparent to the O/S, so Unix gets to see the entire drive
minus the 30 meg DOS partition that I set aside.  The only problem
I had is that Unix was not happy unless I allocated the DOS
partition starting at cylinder 0.  I'd rather have the DOS
partition in the high numbered cylinders in case a DOS program bombs
out and tries to write past the end of the partition.  Oh well...

The WD-1007V-SE2 may not be the fastest controller in existance,
but it isn't a slouch by any means either.

==Bill==
-- 
Bill Mayhew  Northeastern Ohio Universities College of Medicine
Rootstown, OH  44272-9995  USA    phone: 216-325-2511
wtm@uhura.neoucom.edu   ....!uunet!aablue!neoucom!wtm
via internet: (140.220.001.001)