Wait states, why only 4M, 68012, LEDs ; HwNote15

Steve Wampler sbw at tapest.UUCP
Thu Nov 30 00:09:14 AEST 1989


In article <613 at uncle.UUCP>, jbm at uncle.UUCP (John B. Milton) writes:
> 
> 	"Does expansion memory run slower than motherboard memory?"
> 
> When the motherboard layout was re-done, the 74258 was dropped.
> 
> What all this means is that, if you have an old machine with the piggy-back
> board and expansion memory, you can get a performance increase by switching
> to a newer motherboard. Well, I think that horse is dead.

What if one (me) populated the expansion board with 150ns chips instead
of the faster (125ns?) chips needed for the motherboard?  I did that because
of the supposed wait state, but after reading the above, I'm wondering if
the slower chips *without* a wait state might not be part of my memory
parity problems.  What is the effect if I don't have a wait state?  (I
know I could check to see if I have a 74258 or not, but if people say
it shouldn't matter (other than performance), then I won't bother prying
open my case!)

Interesting developments.
-- 
Steve Wampler	{...!arizona!naucse!tapest!sbw}
	        {...!ditka!tapest!sbw}



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