IBM 5162 BIOS dated 1989-04-28

[per]

I'd think not. There are a few differences that would probably trip it up.

To my knowledge, the only differences between the XT-286 and the AT motherboards are the XT form factor, zero-waitstate RAM, 4.77MHz 287 in ext. clock mode and the possibility of 640KB onboard (can be set to only use 512K of it like in the AT). I don't see a reason why this XT-286 BIOS shouldn't work in an AT (in particular since it's patched to not have the speed-check).

 

[jammaster]

Hi all!
I'm the french seller of this great machine.
I'm working on mine these days...

 

[fritz]

Hi All !

cool stuff! I'm of course curious (and will try myself):
Other than the modified BIOS, a 16MHz OSC crystal and an 8 MHz CPU - what else needs to be upgraded for more speed? Faster memory?
Thanks for any hint!

 

[fritz]

Hi,

It works - upgrading the crytal to 16MHz, 32pF (no soldering required), the 80286 to 8MHz and programming new U34 and U35 BIOS chips (using 100ns 27C256B EPROMs)!

BR Fritz