Thanks for fixing the double wide mode ... some more testing
I've uploaded another archive to the FTP containing two disk images I've fixed (one with DOS 1.25 and BASIC-86 and the other one the first image of the backup that was supposed to be bootable but was missing COMMAND.COM). The archive also contains a disk with a whittled down ACAD ...
This image takes almost 10 minutes to render on the real thing.
Unthrottled MAME is considerably faster
On the other hand, a floppy disk takes 1:29 mins to format on hardware (from the "press any key" prompt to showing the disks capacity), but the emulated Duet-16 needs about 3:13. Initially this fooled me into thinking that formatting didn't work.
Another peculiar thing is that they appear to have changed the parameter separator from "/" to "-" between DOS versions 1.25 and 2.11. I will check the manuals next week.
So on DOS 1.25 it"s "dir /w" and "format b: /s" whereas DOS 2.11 takes "dir -w" and "format -s".