Part # M27C2001-10F1, ST Micro brand. High speed 2 MBit (256Kb x 8) EPROM. Ideally suited for microprocessor systems requiring large programs. 5V ± 10% supply voltage, fast access time 55ns, low power consumption: active current 30mA at 5Mhz, stand by current 100uA; programming voltage: 12.75V ± 0.25V, programming time: 100uS/byte.