Path: utzoo!mnetor!spectrix!clewis
From: clewis@spectrix.UUCP (Chris R. Lewis)
Newsgroups: comp.unix.microport
Subject: Re: MicroPort Unix V/AT (Clone disk and other problems)
Message-ID: <481@spectrix.UUCP>
Date: 3 Mar 88 00:57:27 GMT
References: <2495@ihuxv.ATT.COM>
Reply-To: clewis@spectrix.UUCP (Chris R. Lewis)
Organization: Spectrix Microsystems Inc., Toronto, Ontario, Canada
Lines: 49
Keywords: Help with 286 DosMerge
Summary: Should have remembered this before

In article <2495@ihuxv.ATT.COM> bareta@ihuxv.ATT.COM (Benyukhis) writes:
>Good afternoon,
>
>I desperately need help with installing the System V/AT
>at the later stages in the installation.
>... it cannot boot of of the hard drive.  I followed
>the installation manual to the letter twice and could not get the
>install to complete.  Is it a disk, drive controller?

People should be aware that Microport V/AT, UNIX 386 and ISC 386/ix do have
problems with *some* controllers and some motherboards.  Should have 
remembered this before.

For example, The ubitquitous Western Digitial AT controller model WD1003 
will *sometimes* not work (at all, or sporadic failures) on a Intel 
AT386 motherboard (other boards too presumably) if the controller is rev. 
"x4" (I think) or earlier.  x6 works fine.  Sometimes if it doesn't work 
for UNIX, it will still work for DOS.  Some other controllers (sorry, 
cannot remember their names) cause problems too - which is why Microport 
(and other vendors) are so quick to blame them.

Take this as a warning: when assembling a UNIX system for AT or 386 based
systems, try to make sure that you can exchange the controller if it doesn't
work properly.  The UNIX vendor may be in a position to be able to recommend
trustworthy controllers to you.

Another gotcha: On 386 systems there is an "Intel-approved method" for 
discovering whether you have a floating point chip (287 or 387) which 
requires some cooperation from the BIOS.  Some BIOSes do not do this
properly and falsely claim that a 287/387 exists.  When the UNIX is booting
and trying to figure out whether you have a FPU, and the BIOS lies and tells
UNIX one is there, the system will crash on the first FPU instruction because
the kernel hasn't configured itself for FPU emulation.  Last I heard
(approximately 4 months ago):

	- AMI BIOS causes this problem.
	- Don't know about AWARD.
	- Phoenix BIOS works correctly.

It is possible for the UNIX to get around this problem.  386/ix had this
problem, but I think it has a workaround now.  Don't know about uPort 386 UNIX.

The crash's diagnostics are a little hard to interpret, so if you think
you might be having this problem, borrow a FPU and try again.  If this
fixes it, sqawk at your UNIX and/or BIOS vendor.
-- 
Chris Lewis, Spectrix Microsystems Inc,
UUCP: {uunet!mnetor, utcsri!utzoo, lsuc, yunexus}!spectrix!clewis
Phone: (416)-474-1955