The bits in a new PROM are all 1s (continuous lines). The PROM programmer creates only 0s by "blowing" the middle out of the 1s. Some earlier units were capable of programming both PROMs and EPROMs.

It functions like a fuse, which, when blown, does not conduct current. See PROM programmer and PLD. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction requires permission.