The monitor built into the Final Cartridge III is one of the best ones for the C64. Some of its unique features are:
- dumping PETSCII (
Icomand), character sets (EC) and sprites (ES) - F3/F5 for scrolling, including backwards disassembly
- drive mode (
OD) to view and change RAM of a drive and execute code there
I have previously released a reverse-engineered version of the monitor that runs stand-alone on a C64, and an adaptation for the monitor to run on the TED series (C16, C116, Plus/4).
The monitor’s biggest weakness is its lack of support for illegal opcodes. I have now added this support.
The source is available on github:
https://github.com/mist64/final_cartridge
See the build instructions there on how to enable illegal opcode support.
KosMon https://gitlab.com/Rhialto/kosmon also supports those features. It is a modified version of some other monitor (and I forgot what it was called…)