Assembler, simulator and assembly-language routines for the Motorola 6809, recovered from an old Subversion repository in October 2021 for RetroChallenge.
The Frankenstein Assembler for the 6809. Quite an old K&R C program, but should still work on modern Linux systems. Can only assemble M6809 code (it does not understand the HD6309 extensions).
BASIC interpreter for the 6809. Inspired by P. J. Brown's Writing Interactive Compilers and Interpreters (1979) but far from finished.
Some documents on the Hitachi 6309, an enhanced 6809. I have a few of these rare chips, but not much software for them.
Software for the 6309 that runs on an obscure winch controller PCB that I found on eBay years ago. Support for UART, simple machine-code monitor.
6809 simulator that I used to run the BASIC during development. Seems to work OK.
Replacement monitor ROMs for the Compukit UK101 fitted with a 6809 CPU in place of its original 6502. Another machine-code monitor, some memory-mapped VDU routines, and a Matrix style display hack that looks great on a green-screen CRT monitor.
This is the real goal of my efforts for RetroChallenge 2021-10: get this code working again on the modified UK101. To do that, I'll need to get the assembler working, connect the PC to a Stag PP42 EPROM programmer (the green-screen CRT monitor in the original Stag PPZ failed some time ago), burn some EPROMs, and run them on real hardware. Then, I can think about writing new 6809 code.