@kenshirriff I remember these! When I was getting my EE degree at Arizona State University back in the mid-80s we had a few development systems for these chips in the lab and I remember reading up on them at the time. They were already obsolete and unused AFAIK but it definitely piqued my curiosity. Sad that they didn't fix the bugs and expand on the concept as it definitely would have been useful. Microchip's dsPIC products came along years later and were very successful in the same space.