Quick and Dirty: The story of 86-DOS & MS-DOS

There are some new interesting tidbits here :slight_smile:


Thanks - a good read!

Slightly surprising to see the 8086 appear in an S100 system - I would have assumed that’s an 8 bit bus.

And as such, I might have expected to see the 8088 on S100 first - but did perhaps the 8088 appear just a little later?

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The original Altair bus was 8 bits, but as it became the S100 standard it got expanded over the years to handle 16 bit data and 24 bit address lines. The Altair did have 16 data lines originally, but 8 were output data and 8 were input data - two separate unidirectional busses. Later on some extra control lines were added to allow these to be used as a single bidirectional 16 bit bus if both cards could handle it.