alain williams writes: > A great example of that was the Motorola M68000 series of processors, it was a > serious contender for "the" CPU to be used in the 1980s. Logically (ie from > the > programming PoV) it was 32 bit but physically (ie looking at how it connected > to the mother board) it was 8, 16, 32 bit - depending on how much you wanted > to
The 8088 (used in the original pc) had an 8 bit external data bus while the 8086 had a full 16 bit bus. The programming model was the same. Later Intel processors also offered a choice of external bus sizes, such as the 32 bit 386DX and the 16/24 bit 386SX (the 386DX could also use a 16 bit bus). It has been argued that IBM chose Intel over Motorola because the 68000 was so powerful that a pc based on it might have competed with some of their entry level business systems. -- John Hasler [email protected] Elmwood, WI USA
