datasheets for 82S21 - Signetics 32x2 SRAM?

[Brad Parker]

Tony Duell wrote:
>
>Quite likely, although the control signals look unconventional. I would 

It turns out it's write-while-read ram (no doubt you've caught up on your
email by now and read the pdf which was posted).

The strobe signal clocks the ram data into a latch.  This is available
for some time, even if you do a write.

>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.

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
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.

Also iverilog and cver both seem to have some small issues but mostly
work.  I've used modelsim too but I perfer to run on linux.

-brad