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Would a IBM PC AT (5170) motherboard drop into a IBM PC XT case?

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mraroid

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Hello...

I was looking around for an IBM PC AT and they seem to be hard to find. I might have a line on a IBM PC XT. If I come across an IBM PC AT motherboard in the future, would the motherboard drip into my case? I know the power supply would need to be changed out (I suspect) and other issues. But would it fit with out me drilling new holes into my case?

Thanks in advance,

mraroid
 
No, the IBM AT motherboard is massive, much bigger than the XT motherboard and definitely won't fit. In fact, it would not fit most AT cases.
 
Timo W. said:
Pretty sure it will fit, as IBM did exactly that with the XT-286.
Click to expand...
There were two sizes of 5170 AT motherboards. The original was large enough to require an L-shaped power supply, as part of the board went underneath it. The second revision of the AT board was smaller, but still too large to fit into an XT case. The XT-286 board is totally different, and created what became known as the "Baby AT" size -- an AT-class motherboard small enough to fit in an XT case. They also had to make the expansion cards shorter, as the original AT ISA cards were too tall to fit.
 
vwestlife.... Was the XT-286 motherboard (Baby AT size) an IBM product, or was it an aftermarket board may by other vendor?

Thanks

mraroid
 
mraroid said:
vwestlife.... Was the XT-286 motherboard (Baby AT size) an IBM product, or was it an aftermarket board may by other vendor?

Thanks

mraroid
Click to expand...

The XT-286 was an IBM board. If you could find an XT-286 board you can drop that into the XT case and you'd have an IBM XT/286 (Model: 5162) machine but with XT badges.
 
Last edited:
mraroid said:
vwestlife.... Was the XT-286 motherboard (Baby AT size) an IBM product, or was it an aftermarket board may by other vendor?
Click to expand...

It was an IBM part. But if all you want is a 286-class motherboard in an XT case and don't care about it being "authentically IBM" most "AT" motherboards from about 1990 onwards were really "Baby AT" size, which is what Lutiana's previous post translates to. (Cases that could take a full 5170-size motherboards were still a thing in some really high-end applications but most consumer desktops and towers were "Baby AT".) I used to stuff 486 and even Pentium motherboards into XT cases with fairly wild abandon so, yeah, you're spoiled for choice if having the IBM label isn't a necessity. The main limitation you run into when picking out a board for an upgrade like this is the left-hand drive bay in a 5160 is low enough it interferes with taller components and SIMM slots on a lot of "full length" boards.

(A really good choice to make an off-brand XT-286 work-alike is a 386sx board; short "Baby AT" motherboards barely deeper than the length of a 16 bit ISA slot were a dime-a-dozen. Here's an example. Get one with an 8mhz de-turbo switch and it'll perform almost identically to a 5162 but with the advantages of 386 memory management.)
 
My two cents: XT motherboard form factor is what got called baby-AT later on. A full AT motherboard is kind of L shaped. I have two PCs with full AT cases and corresponding motherboards: IBM AT 5170 and a Everex ATplus from 1985.
 
I put a Tyan Tsunami S1830 into a IBM XT case, it's a sleeper. Any standard size AT class board will fit in the XT case. The 5170 AT is not a standard size board but a server size board for it's time IMHO.

framer

 
I have a very interesting full size AT 486 board from 1991. It uses a Zymos POACH chipset grafted to the 486 with a bunch of glue logic and PALs. Cache support too.
 
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