Screen Updating

[Lance Norskog]

Folks, I blew it.

The Fortune screen does not update at 45kbaud, it updates at 45k chars/sec,
or 450kbaud.  This is from a test which just writes a 2000-char buffer
of ascii text.  The screen hardware is a simple character generator,
with 8 bits of attribute space for each 8 bits of character.

Our architecture allows the screen driver to reside in fast (expensive)
RAM or slow (cheaper) ROM, with a 3/2 performance hit.  We put it in ROM.
When we had it in RAM, it ran at 75k chars/sec.

Obviously, a tty driver page mode is not a luxury in this situation.

Lance C. Norskog
Fortune Systems, 101 Twin Dolphin Drive, Redwood City, CA
{cbosgd,hpda,harpo,sri-unix,amd70,decvax!ihnp4,allegra}!fortune!norskog