41xxx
Examples of 4116 class RAM chips
Examples of 4132 class RAM chips ( stacked/piggybacked chips ) (18 pins, not 16)
Examples of 4164 class RAM chips
Examples of 41128 class RAM chips ( stacked/piggybacked chips )
Examples of 41256 class RAM chips
Power pins on 4116/4132/4164/41128/41256
51xxx
Examples of 5164 class RAM chips ( appears to be a CMOS version of 4164 )