asm6809 is a portable cross assembler targeting the Motorola 6809 and Hitachi 6309.

Features arbitrarily complex expressions (with most C-style operators available), forward references, macro expansion and conditional assembly. Output formats are: Raw binary, DragonDOS binary, CoCo RS-DOS (or "DECB") binary, Motorola SREC, Intel HEX.


Falling blocks puzzle game for the Dragon 32/64 and Tandy Colour Computer. 1 or 2 players! Written in 100% Machine Code!


25 levels of monsters & magic for the Dragon 32/64 and Tandy Colour Computer. 1–4 simultaneous players! Written in 100% Machine Code!

Dunjunz for the Dragon and Tandy Colour Computer is a rewrite of Julian Avis's BBC Micro original.


evilwm is a minimalist window manager for the X Window System.

Recent(-ish) development greatly improves evilwm's usability in multi-monitor environments, and add control key/button configuration.


XRoar emulates the Dragon 32/64; Tandy Colour Computers 1, 2 and 3; the Tandy MC-10; and some other similar machines or clones. It runs on a wide variety of platforms. Or try XRoar Online directly in your browser.


Dragon 64 motherboard

Schematic capture and PCB layout in KiCad. Built & working.


A CPLD-based drop-in replacement for the SN74LS783/MC6883 Synchronous Address Multiplexer or later SN74LS785 variant. Schematic, PCB layout and VHDL source.


Dragon computers

Technical information, history and software for the Dragon 32, Dragon 64 and related computers.

Sock Master's Web Site

John Kowalski's web site hosting seems to have been retired, so it's mirrored here with permission (including his GIME register reference).