🚀 go-pugleaf

In article <6982@uceng.UC.EDU> dsims@uceng.UC.EDU (david l sims) writes:
>Programs like Carbon Copy & PC-Anywhere let the remote user run programs
>that use direct screen writes. How do CC & PCA do it on an 8088? (I've
>heard that the 80386 can set "hardware breakpoints", but I digress.)

I don't know how those ones do it, but Desqview does the same thing when
you do direct writes to its video buffer, and has a patent (!) on its
algorithm.  I don't know how DV does it either, but from the look of it,
it checks very frequently near the cursor, less frequently away from it.

Another idea is to use error-correcting code methods:  sophisticated variants 
on keeping row and column checksums might make it fast to detect changes
without comparing every byte. 

Duncan Murdoch