Will it work?

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 03/08/2019 at 16:080 Comments

While waiting for the prototype board, it became clear that some small changes are desirable for much easier programming. Today the board came in and it's already obsoleted. To test our ideas, we add two patch wires and change the resistors from pull-up to pull-down. The pins for banking will also change, but I didn't bother to patch those as I put in the original 32K chip anyway. Nothing is socketed, so it fits inside the existing enclosure. Will it work?