MC6801/MC6805 Single-Chip Microcomputer Family


This paper is from 1979, which would have been a year after I joined Motorola. It was written by Ed Rupp and Mike Wiles. It is titled "MC6801/MC6805 Single-Chip Microcomputer Family". I'm a little surprised that it covers the 6805 as well as the 6801, because I wouldn't have thought we released any info on the 6805 then - I remember the GMCM (I think it was called) or the publicly-branded 6801 probably came out about that time (as I started at Motorola). In theory, I was hired in as a "high-end" guy, but I had to learn all the 8-bit parts (incl the 6801) so we could be sure the 68000 would play well with them, plus I had to go spew the wonders of all the micro product line on some nation-wide road show we went on a few months after I hired on (that's all another story). But I thought the '05 didn't come out until a couple years later. Hey, that 6801 had only 2K bytes of ROM in it! And I'm guessing that it was a couple more years before we had on-chip EPROM versions. My how times have changed!

As I recall, Ed was more of a software guy and Mike was definitely a hardware guy. Tho Joel Boney was the software guy alongside Terry Ritter as the hardware guy on the 6809. I seem to recall some inside chuckling about the mnemonicfor the sign-extend instruction being SEX, and Terry getting his initials in as the mnemonic for the "transfer" instruction, TSR (Terry S Ritter) in the 6809.