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.
Right. But that's assuming simplistic coding/logic.
What if it got real real hard?
Then it's "impossible". Consider hackery that executes the same byte
stream twice, one byte out of sync. Or constructs the address to
access video memory at run time. Or constructs the instruction
sequence to do so at run time.
/~\ The ASCII der Mouse
\ / Ribbon Campaign
X Against HTML mouse at rodents.montreal.qc.ca
/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B