jwbarrus@athena.mit.edu (John W Barrus) (08/21/90)
I was just working with someone to install a new 386sx motherboard in their old
IBM XT. It looked like we would just need $500 dollars worth of motherboard
(included 2M of memory) to do the trick, because I had an old AT
keyboard that he
could use. After we got the new motherboard installed in his old
system, we
talked to tech support at the place where we got the board and they
suggested that we not use old 8-bit HD controller boards (even though
they told us that there was no problem when we were *placing* the
order.) They said that people have had nothing but trouble with 8-bit
controllers in 386sx's because of the speedup. (I have also heard
elsewhere that slow harddisks with 8-bit controllers can hobble
otherwise fast machinery.)
He already had a nice 16-bit VGA card and monitor (besides his original
monochrome card and monitor) and a Seagate 251-1 (28ms, 42Meg) drive
that he had added to his XT. We could use both of those on a new
system. If we payed around $900 for a completely new system without a
hard disk or video, but with an HD/FD controller, and sold the old
system (PC/XT's are going for around $600 on the Boston Computer
Exchange) he would spend the same or less for a much better, well
integrated system.
Anyways, I know I'm rambling, but my one experience in trying to upgrade
an XT to a 386sx style machine has convinced me not to try it again,
because it isn't a good fit. You generally need a new FD/HD controller,
a 200Watt or better power supply (which may mean a new case), and a new
keyboard.
Motherboard $450
Keyboard $ 75
PowerSupply $100
FD/HD Cont $ 75
Memory $100
====
Total $800
and you don't have enough left of your XT to sell to someone else.
(Surely you can get more than $100 for a working XT.)
Note:
I guess I didn't figure the price of the monitor and display into the
$900 for the new machine, so that will add a little more money to the
price, or a lot more if you want VGA.
Anyways, I wouldn't try it again, because of the amount of work and
frustration. When I upgrade, I will buy a new system and sell my old
one. The main lesson is that you need to be aware of all the things
that need replaced when upgrading from and 8088 class machine.
John Barrus
jwbarrus@athena.mit.eduboutell@freezer.it.udel.edu (Tom Boutell) (08/21/90)
After years of surviving with zen- like aplomb on an unaccelerated 8mhz XT, I've admitted I need a bit more speed if I'm going to avoid 5- minute delays while loading Quickbasic source code into the environment and the like. So, my question: I've seen many "XT- footprint AT motherboards" that will supposedly fit an XT case. - Will my existing 32mb ST238 hard drive work OK, and will it need to be reformatted? (I am aware that it won't run at AT speeds.) - Can I expect problems with my I/O card? Needless to say I need my serial and printer ports intact. - Has anyone *tried* one of these motherboards? Is it a good replacement solution? If you can recommend one, brand, source and price would be greatly appreciated. I'm interested in a true AT solution because I gather accelerators would not allow me to run any protected- mode software. (I'm not looking to run OS/2, but there are several Unixalikes I'd like to play with a little.) However, I do *not* necessarily need a 386 or even 386SX solution. Cheap is the main thing, and if it's cheap enough I can forego protected mode software altogether in favor of a "very very very fast XT." Please respond by email as I do not normally read this newsgroup. -- What do you want from the fish of the fish that you fished when you fished for the fish that you fished? How many numchuks could Chuck chuck if Chuck could chuck numchuks? boutell@freezer.it.udel.edu? Or 27.598234821? Or not? -- What do you want from the fish of the fish that you fished when you fished for the fish that you fished? How many numchuks could Chuck chuck if Chuck could chuck numchuks? boutell@freezer.it.udel.edu? Or 27.598234821? Or not?
xevious@bucc2.UUCP (08/23/90)
We upgraded our Xt's to 286 12Mhz motherboards. We originally got them from a
place called Syntax Computers. DO NOT get motherboards (Protek) from these
people!!
We had nothing but hassles. We ended up sending them back for a refund.
DO get a DTK motherboard if you are looking to upgrade! We got these, put them
in and plugged in the peripherals. After going throught the setup program,
everything worked great!! Honest! No nightmares with these babies!
The one XT had a RLL 32 Meg controller on it. (8 bit) We could use the drive
with the data already on it as long as we didn't specify a drive in the setup.
If you DO specify the drive in the setup, you MIGHT have to re-format it.
I had a 20meg Seagate MFM that I had to reformat. We did the RLL just to be
safe. But you can backup your hardrive with your favorite program, format the
hard drive and restore it.
The boards we got went for $174. They came with 2 serial and 1 parallel on
the motherboard. They fit into an XT size case and can take up to 36
41256 memory chips for 1 meg of ram. They have 8 slots and selectable
8/12 Mhz speeds. The serial/parallel interupts are also user selectable by way
of jumpers.
We had no problem running 8-bit cards on the 286's. They are slower, but they
do work.
SO:
Motherboard $174
Memory $36 (36 chips - 18 already in XT)
--------
$210 total!
Note: Chips have to be at least 120ns chips to work in 286. I was lucky in that
my XT had 120ns chips in it.
xevious@cc2.bradley.edu