Development, round II

From: jpero_at_cgo.wave.ca <(jpero_at_cgo.wave.ca)>
Date: Fri Jan 30 17:21:32 1998

> >
> > If I remember correctly, IBM released the XT 286 when the second generation
> > PC/AT (with a faster clock - wasn't it 8 MHz?) came out. It was my
>
> The second version of the AT motherboard came in 6MHz and 8MHz versions
> (according to the schematics), although I've only ever seen the latter.
> The main difference over the earlier version was the use of 256K DRAMs
> (16 of them) rather than those strange piggybacked 128K DRAMs used on the
> earlier board.
>
> There were changes to the BIOS as well, to handle more types of hard
> disk, and so that it wouldn't moan about the faster CPU.
>
> > impression then that the XT286 was an XT case with the older original AT
> > motherboard inside.
> >
>
> AFAIK the old AT motherboard won't fit in an XT case. The XT-286
> motherboard is physically very different to any IBM PC/AT motherboard
> that I've ever seen, although it's electrically very similar.
>
> -tony

Actually, performance wise, XT-286 at 6mhz is exactly same as AT but
mucho improved in designs and performs well compared to type 2 8mhz
board due to 0 wait state. That makes it looks well-tuned machine
using most of the parts using 6mhz cpu, 150ns ram. I approve of this
for full 640K using standard 64k x 4, x 1 and simms. Also nice
touch that XT 286 has 1.44mb support directly in bios instead of
half-baked 512k or 256k ram. IMHO

Jason D.
email: jpero_at_cgo.wave.ca
Pero, Jason D.
Received on Fri Jan 30 1998 - 17:21:32 GMT