datasheets for 82S21 - Signetics 32x2 SRAM?
ard at p850ug1.demon.co.uk
Thu Sep 8 15:57:29 CDT 2005
> >What device uses this RAM, and what are the control pins conencted to?
> It's used in the MIT CADR lisp machine, for the m-memory, which is a
> high speed scratch pad used by the microcode.
Oooh... very nice...
> I wrote some programs to convert the original CAD files (in SUDS) into
> verilog and I've been (slowly) working on getting them to simulate. I
> want to boot one under simulation and eventually put one in a simple
> fpga (hah, by the time I'm 75 at this rate). I figure they'll make nice
My experience with simulators suggests that's a massive _underestimate_
of the time it would take.
> christmas gifts :-)
> I've got it fetching microcode from the prom. Most of the problems have
> been with 74 style 'parts' I have made - in some cases I had to guess
> because I have no data sheet but I'm slowly fixing that.
FWIW< I have a reasonably complete set of TTL databooks from several
manufactueres. Let me know if there's any 74-series part you want me to
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