Close

Microchess and becoming an Apple-1

A project log for Gigatron TTL microcomputer

Just because! A home computer without microprocessor

Marcel van KervinckMarcel van Kervinck 06/23/2019 at 19:540 Comments

Today my Gigatron believes it's an Apple-1 instead of a TTL computer. It's running the original 6502 wozmon code with mockup terminal I/O patched to it. Of course the patching, and some relocation, make up for the system differences. With a tongue in the cheek, we can say it turns the Gigatron into an Apple-1 clone!(*)

Here we can see the "Apple-1 on TTL" running MicroChess code for the first time, with kudos to @oscarv for helping out.

(*) After all: "Apple1 = 6502 + RAM + WozMon ROM + PIA", and "PIA = DSP + KBD". There wasn't more to it and we emulate it all!

In reality, any original Apple-1 software will likely need some relocation and a tiny bit of patching for I/O. More technical details in the user forum: https://forum.gigatron.io/viewtopic.php?p=774#p774

Discussions