This is a (partial) emulation of a BBC Micro in Python - it includes emulation of a 6502 CPU and enough supporting hardware to boot MOS 1.2 and get to the BASIC prompt.

There's no keyboard or display (or indeed, any other I/O) support as yet - at the moment, output is done by hooking the OS_WRCH syscall and printing the contents of the A register to stdout. The emulator will essentially hang when it gets to an OS_RDCH as it's waiting for a keypress that will never come.

To run the emulator, run python PyBeeb.py.

I've tested it with Python 2.7; it won't work with Python 3, I'm afraid.

It's possible to replace parts of the CPU with custom implementations; for example, see Disassembler.py for an example of how to replace the execution unit to turn the emulator into a disassembler. This is also used for the verbose/PC-trace debugging instrumentation.