STILES@USU.BITNET (06/20/88)
1. Switching to a faster part will definitely shorten the memory states, so
you may have to change your configuration.
2. We have found just about the speed-up expected from the faster clock by
replacing 15 MHz T4s with 20 MHz T4s. 20 MHz T8s run about seven times
faste than 20 MHz T4s in number crunching applications.
3. If you are building your own boards, be careful. We have several circuits
that run well with T4s but are flakey or do not run at all with T8s;
perhaps the T8 has a little less drive on the outputs or is a bit
tighter on the specs. The links also seem to be more senstive on the
T8; it does better with cleaner wire-wrap jobs. Some of the T8 pins
also float to different levels than those of the T4; we left out a chip
that was driving the event request pin: T4 ran fine in the circuit, but
on the T8 the pin appararently floated to the active state and the
processor hung after the configuration data was read in - waiting to
process the event.
Dyke Stiles
Utah State University.