Hello Arlen, I am a consulting engineer working with a client up in Sacramento, CA that has a Model AA-545 development system (S/N 5129 CEI) used to program a Motorola MC68HC05C8 microprocessor back in the late 1980's. We are also interested in learning more about this system and if there is someone out there who could use it... We do have some 5 1/4 in floppy's (MS -DOS 2.0) for the system. Did you ever find any further information during your search in July? Perhaps we can in some way help eachother? Regards, Chuck Clemens Medical Device Development Consulting Office: 760-942-2272 Cell: 760-613-2272 Fax: 760-436-9476 Net: clemensco(a)aol.com