(PROM) that is both non-volatile and re-programmable.

Early types of floating-gate memory included EPROM (erasable PROM) and EEPROM (electrically erasable PROM) in the 1970s. However, early floating-gate memory required engineers to build a memory cell for each bit of data, which proved to be cumbersome, slow, and expensive, restricting floating-gate memory to niche applications in the 1970s, such as military equipment