vc83 as ac6502 cartridge

[acwright]

Hey! I was able to do some work on modifying your existing ac6502 configuration in order to run vc83 as a cartridge on my system which is the preferred method for software on my system. Thanks for your help on getting it running in program space which helped a lot with this implementation!

You can run this with my emulator (https://github.com/acwright/6502-EMULATOR) using:

ac6502 -r /path/to/bios.bin -c /path/to/basic_ac6502

[willisblackburn]

Thanks for this! It's excellent, and I merged it as-is. But I have a few comments, if you'd like to make it a little better.

1. Change copyright to your name, or at least add your name, since it's obviously your work not mine.

2. Fall-through works for PVM so you can just do this and save a few bytes.

ex_pvm_arg_4:
        CALL pvm_expression
        ARGSEP
ex_pvm_arg_3:
        CALL pvm_expression
        ARGSEP
        CALL pvm_expression
        ARGSEP
        JUMP pvm_expression

3. I think you can just get rid of initialize_target if you want because you can handle everything in startup. Your code is in ROM so you don't get any advantage to putting stuff in the ONCE segment.