henry (01/06/83)
One thing tucc!watts didn't mention about the software memory refresh on the Sun. It does not necessarily have to be 128 NOPs that the software executes every 2 ms. It's quite possible for that code to do something useful, provided that it does touch all 128 possible combinations of low-order bits. This would in general require hand-crafted assembly code, but the amount is small enough to be manageable. Tom Duff at Lucasfilm, for example, does his mouse polling in the refresh routine.