29 Jan
1998
29 Jan
'98
1:25 p.m.
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
impression then that the XT286 was an XT case with the older original AT
motherboard inside.
-----Original Message-----
From: Mike Allison <mallison(a)konnections.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Thursday, January 29, 1998 10:04 PM
Subject: Re: Development, round II
Tony:
I just seem to remember _something_ about the XT286 that made me avoid
it for true 286 stuff. Maybe it was the memory. Most after market AT
boards had room for a meg or two. Maybe it was the 640...
-Mike
Tony Duell wrote:
I've not got the XT-286 techref to hand, so I
can't look at the
schematics. But I seem to remember that it's _very_ similar to the PC/AT
- it's a lot closer to that machine than to the XT. There are 2 DMA
controllers, 2 interrupt controllers, the 8042 keyboard controller (so it
takes an AT keyboard), etc. My thoughts when I looked at the schematics
were that it was a repackaged AT. Of course they could have missed out
the extra reset logic, but I doubt it.
It does use a non-standard motherboard, though. The memory is a little
odd - 128K in DIPs (4 off 64K*4, 2 off 64K*1 for the parrity) and 2 256K
SIMMs for a total of 640K.
I guess....
-Mike
-tony