386 upgrade boards for IBM 5160s

Fred Cisin cisin at xenosoft.com
Tue Nov 3 16:24:43 CST 2009

On Tue, 3 Nov 2009, Sridhar Ayengar wrote:
> That's weird.  I never had to do anything like that...  I just had
> HIMEM.SYS in the CONFIG.SYS of my PS/2 Model 50 (1MB RAM, 286 at 10MHz),
> and it Just Worked(tm).

Doesn't the 50 default to 640K at 0h and 384K at 10000h?
Or is 384K just unavailable in real mode?

In August 1991, I tried to install beta 3.10 on a TI "Travelmate"
(at Microsoft Developer's Conference) I was the apparently the first, of
eventually millions of people, to complain about it turning on
write-caching.  Some of the MICROS~1 staff told me that the installation
failure was explicitly due to HIMEM.SYS not having access to anything
above 1 MB.  Until now, I never had any reason to doubt their explanation.
I only had one 80286 machine that gave me a choice of where that 384K was
going to be, and it also failed to install with the 1MB being contiguous.

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