Using the TD8-E with the MS8-C memories
bob at jfcl.com
Tue Apr 29 09:04:02 CDT 2008
Is it possible (i.e. is the CPU fast enough) to use a TD8-E in an 8A6xx
machine (KK8-E CPU) and the MS8-C memory?
I know the original MOS memories for the 8/A, the MS8-A, were _waaayyyy_
too slow work with the TD8E, but it appears that the MS8C is a lot faster.
Thanks to David Gesswein I found a manual for the MS8-C here
If I read it right, it seems to say that the MS8C has a cycle time of
1.2/1.4us (i.e. just as fast as the KK8-E) and that it does
transparent refresh (i.e. the refresh doesn't slow down the CPU at all).
And if I'm still reading right, it seems like the only time the MS8C uses
NTS STALL is when the processor first starts up (i.e. goes from the HALT
state to RUN), and that's just to synchronize the transparent refresh cycles
with the CPU. If all that's correct, then it ought to be possible to use the
MS8C with the TD8E.
Does anybody know if this is true before I pull my hair out trying to get
it to work? And if that works, is it also possible to use the KK8-A CPU
(slightly slower than the KK8-E) in the same configuration? I have both CPU
card sets, but the KK8-A takes fewer slots.
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