can someone tell me the difference if there is one between the master 6801 and the other 2 on the adam board or they can be swap with out prob
They can't be swapped out, because they have different code inside. Moreover, they are all mask ROMs, manufactured with the program inside, so there is no way to change it. An EPROM version of the microcontroller exists, 68701, for development purposes, but these chips and devices to write them are now rare.
If you're interested in the code differences, you can see PDFs of the original source code listings: Master 6801ADAM printer 6801Digital Data Drive 6801
There is also a 6801 source code archive
which has binaries of the above listings, plus binaries and disassembly source code for the ADAM keyboard and prototype serial/parallel device.
Chris Braymen was responsible for all of this info (he found the code listings in a back room at Sierra Online Games when he worked there). I did the restoration of the missing page 1 of the ADAM printer source code listing.
Edited by Dr. D., Sun Sep 29, 2013 9:07 AM.