🚀 go-pugleaf

Periodically people make reference to the "XOR" patent on this
and other groups. Are they referring to a couple of patents
held by the CADTRAK corporation that deal with issues such as
double-buffering, scrolling, video enlargement and cursor movement?

I've seen various postings to the effect that "The XOR patent can
be violated with one line of code." To the best of my knowledge,
the CADTRAK patents are enforced almost entirely against hardware
vendors who sell entire systems that include any video subsytem 
more sophisticated than Hercules. 

Last I heard they were embroiled with Commodore, and the case was dragging 
out considerably. Does the XOR patent == the CADTRAK patents, or
am I confusing two different creatures? I have also heard of a
"backing store" patent, and even an "XOR backing store patent". Where
do these fit in, or is someone else even more confused than I am?

doug

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douglas barnes                               Calgon can't take me away...
barnesdo@CS.ColoState.EDU                 From the things I did today -L7