Howto make small alterations to existing roms for own use

[petersieg]

Upfront: The best way to use additional apps/programs is to use a uSD solution. Either Pluggy Reloaded with Loader function or spi uSD at 128k Ram and I/O extension with spi loader in rom.
Second: It does not make too much sense to flood the world with roms, that are just slight variantions from existing work. This is meant for own use.
I have two gigatrons with uSD card adapter, but one "naked" - just plain gigatron mainboard. On this one, I wanted to have some other games/demos as was available. That was the only reason, I looked into "baking" my own variation of a rom.

Please find my notes taken here attached - maybe it helps if you have a similiar need.

I must say, that 90% of the rom codes and pieces, I don't understand! I just understood enough to get to my goal.
I don't know, it the sequence for example of entries does matter?
Bouncer and gtmine did not run as expected, when is was trying to use them?
...

Of course, you should test the altered rom upfront in an emulator, before putting it in real hardware.

And NO WARRANTY whatsoever for the information given here. It worked for me. YMMV.

best, Peter