A project log for Gigatron I/O and RAM expander

Adding four SPI ports and up to 128K of banked RAM using nothing more than 4 TTL chips and some wizardry.

Marcel van KervinckMarcel van Kervinck 12/15/2019 at 14:570 Comments

As of yesterday, DEVROM itself can detect a memory card during reset. When detected it will continue to boot from there instead of jumping to the built-in main menu. This means you don't need the Arduino route anymore when playing with the expander.

Naturally everything still needs refinements. But from here we can theoretically bootstrap an entire new system without ever updating the EPROM again, and without being tethered to a laptop/PC.

Some unrelated but noteworthy recent updates: