[rbanffy]

No. He ran out and acquired 86-DOS, from Seattle Computer Products. It's easy to have something when you buy it already complete.

And DR had CP/M-86.

[whobre]

DRI did not have CP/M-86 at that time which is the reason Tim Paterson developed 86-DOS in the first place.

[rbanffy]

CP/M-86 was first expected to be delivered in 1979, so I assume it existed in one form or another prior to that, shipments pending hardware availability. I wouldn't expect DRI to fund the adaptation without a cooperative manufacturer unless there were a significant installed base.

[canucker2016]

MS still had to make modifications to Tim Patterson's 86-DOS before it shipped as PC-DOS 1.0 - source: Paul Allen's Idea Man autobiography.

[rbanffy]

Of course - the PC didn't exist when SCP made 86-DOS. The same way as with CP/M, the hardware interface had to be written.

[indigodaddy]

Same thing, he did the needful to have something to give ibm.