First version, complete

The first version suitable for general use

Final prototype2 version

Final version of the code for running on my second prototype board. This is feature complete and has the design for the first lay flat hardware. From this point on I expect to be tuning and bug fixing.

Final prototype1 version

Final version of the code for running on my first prototype board.

v1.1 ROM emulation working

Updates to the original v1.0 board. These were done by hand modifying, I didn't get this design fabricated.

The 2 ZX->Pico level shifters were removed since experimentation shows they're not required. Pico GPIOs are 5V tolerant when used as inputs. Using /RD as direction for the data bus level shifter was wrong, the shifter took the bus when RAM reads happened. oops. That's now driven from ROM_READ_INV and works correctly. Transistor Q1 footprint fixed.