25th Anniversary of the Personal Computer" 4204

since how

Not that I ever heard of. Anyway, the 8088 address bus is 20 bits. Eight shared with the data bus, four shared with the S signals, and eight on their own.

You mean memory DATA bus, not memory ADDRESS bus. Or, actually, the overall data bus. Additional arguments were that the 8088 made easier use of 8080 perhiperal chips, though I recall several 8086 based systems which handled those devices without any apparent trouble.

Seems unlikely. If IBM had issues with Motorola (and someone else in this thread noted a good reason that such may well have been true) the 6809 would have suffered the same problems. More, the 6809 came out in 1979 and wasn't really established (to what extent it ever was) until '80 or maybe later. The 8086 was out in '78 and it and the 8088 were well established by the time IBM was making CPU decisions.

The 286 wasn't introduced until 1982, a year after the PC. While I suppose Intel told IBM about their plans for it (or not, wasn't the 286 a stopgap while the 432 was developed?), I'm not sure how much weight they'd have placed on a planned CPU when actual ones were at hand.

It didn't. I know a couple of OS-9 die-hards and they never saw much point in using it on 68K machines.

- Bill