A virtual machine based around a 6502 processor written in Go.
During lockdown 2020 I experimented with a simple 6502 virtual machine by placing the existing C fake6502 emulator into my own wrapper. It worked reasonably well but was missing basic things like comprehensive tests and a decent UI (don't judge me too harshly, it was a throw away project just for fun).
I was never satisfied with the full quality of the user experience and wanted to do more. In particular I wanted an easy to extend 6502 emulator that allowed me to simulate many different variants of 6502 processors and even generate my own. I also much prefer Go to C or C++.
This project is the result. Currently, it has a functionally working processor that passes the Klaus2m5 functional test suite. Most machine cycle counts will be correct but there is still work to do to make this fully accurate, particularly around the branching instructions.
There is a decent list of work still to do, in no particular order:
- Accurate instruction counts.
- BCD tests for undocumented behaviour.
- Undocumented and extended instructions.
- 65C02 support.
- DFBP custom CPU support (for experiments).
- Assembler/Disassembler.
- Debugger.
- VM wrapper to allow execution of arbitrary programs.