individual pixel display

[BAKERWL at uwyo.edu]

It would be nice to be able to display a map, then be able to change
a single pixel in the display without redisplaying the whole map.  This
would be a desirable feature for modeling certain phenomena in action.
Redisplaying the map takes lots of time when the map is large.  

With my programming skills, it would be a waste of time to try to look
into the XDRIVER code, but perhaps there would be an easier way to do
this.  Has anyone pondered it?

        Bill Baker
        bakerwl at uwyo.edu