Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!umich!wsu-cs!egrunix!besler
From: besler@egrunix.UUCP (Brent Besler)
Newsgroups: comp.sys.ibm.pc
Subject: Re: XT to 386SX upgrade
Message-ID: <428@egrunix.UUCP>
Date: 8 Feb 90 17:54:48 GMT
References: <10650@saturn.ucsc.edu>
Reply-To: besler@unix.secs.oakland.edu.UUCP (Brent Besler)
Distribution: usa
Organization: Oakland University, Rochester, MI
Lines: 47

>I would like to hear from anyone who has upgraded an XT to a 386SX by 
>replacing the motherboard. I would like to find an inexpensive one, but
>not cheap.
>1) Are there some chip-sets that are better than others? Especially in
>	terms of memory management.
Try to find a board with the Chips and Technoligies NEAT chipset and an
AMI or Pheonix BIOS

>2) Will it fit into an XT flip-top case? Especially height.
Most of the motherboards are the right size.  You may have to drill some
holes though to secure it inot the case
>3) Is the 150W power supply OK?
Some motherboards will work with XT power supplies, others won't.  The Jameco
386 board(20 Mhz) I put in my XT case did.  150 watts is OK is you only have
one hard disk.
>4) Will these cards work with an SX and how well (in general)?
>	A) video
>	B) HD controller
>	C) FD controller
>	D) port card
>	E) 2400 baud modem
You may need to replace the HD controller.  If you do I would get a dual/HD
floppy controller(WD 1006VSR2 or WD 10006 VMM2 [RLL or MFM] recommended).
I had no problems with my original cards.  I even booted of floppy with the
old XT floppy controller.  I had an old WD RLL card in the XT.  WD tech support
said teh card probably wouldn't work in over 12 Mhz systems.
> If they will work, but not very fast(compared to the 386), that may be OK, 
>  as the rest of the system could be upgraded a bit at a time as I can 
>  afford it.
The hard disk I/O is going to bog down the 386SX.

>Any help is welcome, but I especially want to hear first hand experiences.
>If there is a lot of interest, I can post a summary.
See a previous post about my experiences upgrading an ARC 8 Mhz 8088 with
a Jameco 386/20 motherboard.

I belive JDR Microdevices has a 386SX board for about $400 built with the NEAT chipset
and an AMI bios. You will have to buy new memory for any of these boards as the
old XT memeory is too slow.  I would recommend a 386/20.  It would cost about
$250 more, but in my opinion the extra speed is worth it.

					  Brent H. Besler
>
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