IIRC it's a true static RAM, 1K*8, 24 pin DIL, pinout similar to the 2716 or 6116. I think WE/ is on pin 21, and I can't remember what's on pin 19 (which would be A10 if it were a 2K device). Maybe nothing, maybe another CS input. It was not commonly used, but my Nascom2 has a few in it...