MOS Technology 6502
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A 6504, a 6502 variant with a 13 bit address bus was used as the floppy disc controller in the Apple Lisa.
A 16-bit extension of the 6502, the 65816, was used in the Apple IIgs.
A pair of 6502s running at 10MHz were used as IOPs (I/O processors) in the Macintosh IIfx, the Quadra 900 and the Quadra 950. One acted as dedicated serial controller, and the other was the floppy disc and serial controller.