On Wed, Jul 17, 2019 at 9:43 AM Mark J. Blair via cctalk < cctalk@classiccmp.org> wrote:
> > On Jul 17, 2019, at 1:20 AM, Paul Birkel <pbir...@gmail.com> wrote: > > From some notes (origin misplaced!) you'll need a typical access time of > > 40ns from address, or 20ns from /CS: > > Thank you! That rules out using a 70ns EEPROM, then. > While the bipolar PROMs were faster, I think 70ns will work on an M9312, though I haven't verified it. The timing for reading the nibbles from the PROM to assemble into a 16-bit word is controlled by a delay line and associated logic, and it looks like the required access time is on the order of 100ns, with a cycle time on the order of 150ns.
