WinWorld has DOS Plus and Concurrent DOS from DR, maybe you could ask the maintainers or forum dwellers there. I found exactly one post on the forum, listing v

WinWorld has DOS Plus and Concurrent DOS from DR, maybe you could ask the maintainers or forum dwellers there. I found exactly one post on the forum, listing various finds from eBay, that says "Digital Research - FlexOS 386 System Builder's Kit, Release 1.42, 1988 - 5 Box"; unfortunately the linked item is gone by now: https://forum.winworldpc.com/discussion/comment/164410#Comment_164410 https://forum.winworldpc.com/discussion/comment/164410#Comme...