> On 7 Dec 2024, at 13:34, Henry Bent <henry.r.bent@gmail.com> wrote:
>
> Also interesting; I wonder if the "capability to run multiple MS-DOS applications under Unix" was shipped in a functional form, and what relation it might or might not have had to what was running on the AT&T hardware.

I used to run an 80286 “Taiwan clone” (as we called them in Italy) with Xenix 286 and, later, its 386 version which was SCO by then (memory a bit fuzzy on when Xenix became SCO Xenix and the Unix) and I definitely could run MS-DOS programs on the 386 - you would use the dos command which mapped drives either to physical drives (i.e. A: was the floppy) or directories within the filesystem.

It was often used for businesses which had their inventory on MS-DOS bespoke software but wanted to “multitask” so we had some very dirty code which would run the DOS program on the serial terminals writing to a “network” drive which was actually a directory in the Unix filesystem.