Disassemblers for the 6800 family of microprocessors
From the TekScope mailing list:
Here is the source for a 6800 disassembler written in c.
http://seanriddle.com/willy3.html
Look at the bottom of the page.
There is this;
http://boomerang.sourceforge.net/
This is for the 6502 with a nice GUI. It should easy to convert it from 6502 to 6800 given the code in the first link. I believe that the 6800 is very similar to the 6502.
Also;
http://sourceforge.net/projects/dis6502/
and another
http://sourceforge.net/projects/mt6502dis/
There is IDA Pro, a commercial product that handles the 6800;
http://www.hex-rays.com/idapro/overview.htm
The guys interested in old games are really active in this area. I have not used any of these since my interest was in the 68020.
Pete.