3 ms·
It is really an 8-bit CPU from a bus (external connections) perspective...but internally, there were 16 bit registers (sort of...) Perhaps this was why he made
by canadian_tired 6y ago
It is really an 8-bit CPU from a bus (external connections) perspective...but internally, there were 16 bit registers (sort of...) Perhaps this was why he made the distinction.
- jhallenworld 6y agoIt's the link between 8-bit and 16-bit: at least that's what Motorola marketing said, look at the cover of this book: https://www.amazon.com/MOTOROLA-MC6809E-MICROPROCESSOR-PROGRAMMING-M6809PM/dp/B000P69K28 https://www.amazon.com/MOTOROLA-MC6809E-MICROPROCESSOR-PROGR...
- ddingus 6y agoI have a copy of that book near me. For a very long time, Moto would send docs out for the mere asking. Free of charge. I got mine as a high schooler. Didn't use the mail though. Instead, I visited a local Moto office and they handed me the ones I wanted and I got to talk chips with the people there for a while. For a small town kid interested in all this stuff, that made quite an impression. Instant Moto fan.
- Zuider 6y agoThe 8-bit A and B accumulators could be addressed together as a 16-bit D accumulator. The contents of A and B could be multiplied with the product stored in D. There were also two 16-bit index registers with advanced and versatile addressing modes, X and Y, along with 16-bit user and system stack pointers, U and S.