▸ ROM LOADER

Upload ROM files (any file extension). Files identified by filename.

Drop ROM files here or click to browse

▸ PRG LOADER

PROGRAM LOADER — Upload .PRG / .PET files (convenience loader for development/testing)

▸ ILLEGAL / UNDOCUMENTED OPCODES

This CPU core implements all 256 opcodes including the "illegal" NMOS 6502 instructions (SLO, RLA, SRE, RRA, SAX, LAX, DCP, ISC, ALR, ANC, ARR, SBX, ANE, LXA, LAS, SHA, SHX, SHY, TAS, USBC), the multi-byte NOP family, and the CPU-freezing JAM/KIL instructions.

— determinizes ANE ($8B) & LXA ($AB). $FF or $00 recommended.
No illegal opcodes executed yet.
▸ DEBUG MONITOR
PC:0000 A:00 X:00 Y:00 SP:FD P:00100100 NV-BDIZC
PIA 1 & VIA REGISTER WATCH