Apple II clone (GTAC-2) motherboard revival

This project is an attempt to revive a 30+ year old GTAC-2 motherboard back to a functioning Apple II clone. The project required some minimal set of missing hardware including a power supply, keyboard, and ROM. The power supply was was adapted to use a modern ATX supply with the -5v rail generated by a 4.7v Zener from the -12v ATX power rail. The ROM card was rebuilt as a plug-in board using a modern EEPROM programmed with original GTAC-2 firmware (or Apple II firmware). The missing keyboard was replaced by a PS2 keyboard interfaced to the system with an AVR ATtiny84.

References

• Apple II ROM disassemply
• MEWA-48 Apple II clone
• Staff C1 (Apple II clone)
• Apple II clone