4ROM_100 is basically the 2.0 version of Teeprom 4ROM_78802 is basically the 2.0 version of Meeprom
Teeprom for TRS-80 Model 100/102/200
Meeprom for anything else with a Molex 78805 socket. (Kyotronic KC-85, TANDY 600, Epson PX-4, Epson PX-8, etc)