The 1541 floppy drive for the C64 used a 6502, almost the same as the C64’s 6510 CPU. Some C64 software co-opted the floppy drive’s 6502 as a coprocessor.
I've seen that one before, but always love seeing this. And particularly love the touch of not using pre-prepared cables but casually unplugging the C64 and cutting apart and splicing the cables with the equipment on...
The 4040 drive for the Commodore business line had TWO 6502 equivalent CPUs. I used to tease a friend who owned one that his floppy drive was smarter than his computer.
> Some C64 software co-opted the floppy drive’s 6502 as a coprocessor.
In that sense, the 8-bit Commodores were a bit like mainframes - one could load a data transform program to run on the floppy drive and run it without bothering the host. I believe it goes a bit further than the Atari family in that.