NEC µPD4164-3 64K x 1 bit Dynamic RAM 5V DIL16

Manufactured by NEC - µPD4164 - DIL16 through hole package

The NEC µPD4164 is a 65,536 words by 1 bit Dynamic N-Channel MOS RAM designed to operate from a single +5V power supply. The negative-voltage substrate bias is internally generated - its operation is both automatic and transparent.
The µPD4164 utilizes a double-poly-layer N-channel silicon gate process which provides high storage cell density, high performance and high reliability.
The µPD4164 uses a single transistor dynamic storage cell and advanced dynamic circuitry throughout, including the 512 sense amplifiers, which assures that power dissipation is minimized. Refresh characteristics have been chosen to maximize yield (low cost to user) while maintaining compatibility between Dynamic RAM generations.
The µPD4164 three-state output is controlled by CAS, independent of RAS. After a valid read or read-modify-write cycle, data is held on the output by holding CAS low.
The data out pin is returned to the high impedance state by returning CAS to a high state. The µPD4164 hidden refresh feature allows CAS to be held low to maintain output data while RAS is used to execute RAS only refresh cycles. Refreshing is accomplished by performing RA"S" only refresh cycles, hidden refresh cycles, or normal read or write cycles on the 128 address combinations of AO through A6 during a 2 ms period.