Dunno if this can help, but i found this interesting website around 6089 emulation:
After seeing the PATHETIC effort Namco made in emulating Mappy for the PC, running under winslows'95 it was terrible. I decided it was about time someone wrote a decent Namco emulation ( for purely educational uses by owners of the original game boards ). Having already learned 6809 assembly programming, through another project, I figured that writing a simulator in x86 assembler wouldn't be a big deal, well the 6809's hardly got any registers and only a small number of instructions ( I think it's like 79 total).
So after a little coding, and a lot of debuggering, the 6809 simulator lived, a few days after that 'hey presto' the Mappy emulator was born! Unlike the official Namco release, which when run on a Pentium Pro @233MHz ( yes I overclock ) only manages 96% original game speed ( or only 31% if the screen is maximized ), mine achieves 100% speed of the original, even on an old Pentium 90 !!
The emulator was coded over a period of about 6 weeks, during the months of May to June. I was looking for something else to do rather than actually complete PC*Bert. The first release of the emulator was at the San Diego Classic Arcade party, have a look at some pictures from that event here http://www.spies.com/arcade/photos/index4.html
After getting the first version out, which were stand alone programs, I decided it'd be a good idea to merge them into one program. The core program can support multiple games, the specifics of each game are handled by a custom 'driver' to emulate the particular hardware. All emulated game share the 'core' routines which handle things like 6809 emulation, sound generation, sprite and text drawing.