> I don't know what spped the M9312 PROMs are rated at but I was just
> looking at my notes about the Bipolar PROMs used in the HP 1000.
> They're rated at 60nS. Can you get EPROMs that are that fast?
No and yes. Worst case timing for a typical 256kbit EPROM is 150ns but
if you know the address will be stable at least 150ns before the data
is required then the delay from /OE to valid data can be as little as
40ns. Also if you know which address lines cause the greatest delay
then you can avoid switching them and operate the with a worst case
delay of about 75ns.
I would guess that, with care, 120ns parts could work and that 90ns
parts would work in place of 60ns bipolar PROMs.
Lee.
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Received on Sat May 29 2004 - 11:25:59 BST