17 Jun
2009
17 Jun
'09
7:12 p.m.
On 17 Jun 2009 at 17:21, Eric Smith wrote:
One problem with taking advantage of a PACE chip (free
or otherwise)
is that the I/O pads aren't compatible with TTL, or with much of
anything else either. The specs are very strange. National made some
buffer and transceiver chips designed to work with it, but of course
they are even more like unobtanium these days than the PACE itself. I
suspect that the easiest thing to interface to it nowdays would be
CD4000B series CMOS logic, which is extremely slow, but then so is the
PACE.
That's exactly what I did. The various PACE interface chips
(STE,MILE, etc) were expensive and not easy to findt, so I made do.
That was also my first exposure to 4000 series CMOS logic.
The whole thing pretty much filled up an S100 prototype card. Lotsa
wires.
--Chuck