Swapping the OS ROM for an EEPROM - Atari 8-Bit Computers - AtariAge Forums
AT28c256 15PI Atmel 256K (32K x 8) CMOS EEPROM NOS Industrial | eBay
Atmel At28c256-15pu EEPROM for sale online | eBay
GitHub - Wh1teRabbitHU/EEPROMAdapter: This adapter can read and write AT28C64 and AT28C256 EEPROM chips. Creating converter PCB for this task recommended