On the 6800/6809: don't forget to look at the Fairlight CMI and the Qasar M8 developed by Tony Furse: the sampling synthesizer that was the sound of the 80s.
This past summer, Tony has been retrieving his 8-inch Motorola Exorciser floppies. He encouraged me to work on my Motorola Exorciser emulator- it now emulates a 6809 version of the Exorciser:
https://github.com/jhallen/exorsim
(check out the long discussions in the issues...)
"Blue Monday" on QasarBeach Fairlight CMI emulator: