Microchip AT28C64B-15PU, 64kbit Parallel EEPROM Memory, 150ns 28-Pin PDIP Parallel

EEPROM (E²PROM) memory is non-volatile RAM that has individual byte addressing for data write, unlike Flash which has to be written/erased in blocks . It does have a limited life in terms of number of write cycles and tends to be used for program storage that is infrequently changed.