- POKE 38928,X - change to mode X imediately
- POKE 38929,X - change to ROM address X imediately
- POKE 38930,X - change to mode X, apply pending ROM change and reset
- POKE 38931,X - preset ROM address for above
This should cover most of the options required. The menu should be able to offer things like
- Run a game cartridge from ROM (8K/16K/Atari 16K/Scott Adams 16K)
- Run the VIC20 diagnostics software (which needs ROM and RAM)
- Run Super Expander or other BASIC with up to 27K RAM
- Exit to BASIC with 3K-35K RAM
But also I think I should be able to get it to run some commands on reset,
- Exit to BASIC with 3K-35K of RAM and execute LOAD "*",8
- Exit to BASIC with 11K-35K of RAM and execute LOAD "FB20-8K",8
- Select a Scott Adams adventure and execute SYS 32592
Being able to autostart a diskimage or the file browser on an SD2IEC (or a 1541 if you like), would be a nice feature to have, and avoiding typing SYS 32592 makes the Scott Adams adventures easier to use.
The new boards are here, the software is taking a bit longer to write.
I have some simple single ROM cartridge PCBs, if you only want to replace a single game.
If you like DIP switches, I still have some of the current version of the PCB available, built and tested with up to 35K RAM and 32 ROM images:
The menu software has been rewritten in C.
Update 4: Penultimate Cartridge V4.3 available now, all menu driven, no DIP switches.