@Infoseepage this is qdos 0.11, it was just called 86-dos already and it was probably wrong, or terminology got mixed up, or

we have a giant disk set from them, and it has up to MS-DOS 2.0, as well as 86-DOS up to December 1981 and something called "DOSV" (NOT Japanese DOS/V) is also referenced sometimes, from 1982

the disks go up to 1987, which is interesting because SCP's last recorded action is suing Microsoft over their license agreement, and settling, in 1986. they claimed offshore (probably Japanese) companies edged them out of the market with lower labor costs or something, maybe 1987 is when SCP went bankrupt

also only 2 or 3 out of dozens of disks had any bad sectors. very high quality stuff...