22 Apr
2007
22 Apr
'07
4:59 p.m.
On 22 Apr 2007 at 8:23, Chris M wrote:
My question is therefore is this practical
or even feasible? My guess is it's possible, but
some
code could be so convoluted that it would be extremely
difficult. In essence the software would need enough
intelligence to reverse engineer another bunch of
code. Could it be done totally by automation...
I suppose it all depends if you're talking about text or graphics.
Text is pretty simple, but graphics bit- and port-level compatibility
is a different matter. Still, it's possible to search an app for
video display buffer segment loads and alter them. Recall that many
apps would work on both MDA/MGA and CGA and so altered which addess
that was used on the fly. Note that apps that used CGA 80x25 text
may not work without more probing as a "stall" waiting for the
retrace interval to avoid snow in the display was very commonly used
and may well cause your application to hang without modification.
Cheers,
Chuck