indra@utai.UUCP (Indra Laksono) (07/24/85)
I have mentioned some time ago, that GEM desktop doesn't run
because of INT EF is used by the Sanyo for some hideous thing. My 1st
solution was to patch ALL the GEM stuff, substituting EF by 40 (including
the SET VECTOR part).
This first method works and I have a working version now, however,
Being of the curious nature, I wondered what would happen if I changed the
BIOS of sanyo. It turns out that it woiks!
This is my solution :
[1] Copy the the 4 bytes starting at 0:3bc to 0:3c0 (ie make
INT F0 = INT EF.
[2] Search through memory for CD EF (INT EF) and substitute with
CD F0. (only one location somewhere at 40:2???).
[3] Load original GEM STARTUP for ibm and you're ready to go.
The problem of NO KEYBOARD STATUS - meaning you can't do INT 16H
with AH=2 (hence no dragging) is solved in a 'kludgy way'.
I have taken INT 5 (Screen Dump [ctrl][shift][del]), and added
a small routine that does nothing but NOT a byte somewhere. Then, INT 16H
AH=2 is trapped and we check if this byte is non zero, return with AL=3.
This is the same as telling it that both shift keys were pressed.
You lose the screen dump vector, but what the heck :-)....
If sanyo users are interested, I'll mail them a program that does
the patch to dos.
..{allegra cornell decvax ihnp4 linus utzoo}!utcsri!utai!indra