Thank you everyone for your help thus far. Im going to try and be even more specific. Im obviously not the most experienced person so please bear with me.

We have been using the AT89s51 chip. One function of our project records the inputs on port1, then based on what is on port2, the output on port3 will vary. We need 2kB of on chip EEPROM or something similar, that when the chip is powered off, all the input on port1 that was recorded, is still there so that when the chip is turned back on, say days later, it does not have to record the input signal and timing again.