Major/noticeable changes to version 2023.05.01.
Occasional “” notice removed from printouts. About popup is shown every 3 hours if not registered.
Support of direct access to (virtual) parallel hardware ports dropped.
FPU emulation rewrite. Only FPUAWARE=0 (no FPU) is still effective.
Mouse clicks outside the content area in full screen are ignored.
Wide font variant (FONT = [-]WIDE) for a 1/8th wider window (mostly for 16:9 full screen).
SCALE= directive dropped.
Extended graphics mode for WP6.x.
Support of 8 text mode video pages (in 25x80).
Dark mode could miscalculate contrast of colors.
COLOR command to select a color theme or set a color at runtime (see Readme.pdf).
TIO: Also valid for non-printing (DUMMY, CLIP, Windows program).
HORZ: Default scaling was 100% instead of documented 95%.
HORZ:/VERT: Overrides eventual embedded PCL margin settings.
Forced page break didn’t account for the top margin.
Full program DOS path with execute was limited to 31, now 95 characters.
Environment size raised to 1 KB.
Programs that hook into INT 21h and start a second program could get messed up.
DOS API 21-36h (Get free disk space) returns 1.9 GB free space instead of 123 MB.
DOS API 21-57h (Get last-written date and time) returned current time (for files).
Download Installation program 2023.05.01  |  Source files and previous versions
First read the little documentation vDos has to offer to make it run your application! Keep in mind you once had to configure DOS, the transition to Windows (XP?) took time. You forgot about that…

Have a look at the FAQs and Forum pages, eventually post your question/problem to the latter. Replies are mostly real quick. If your issue however seems specific to your situation/application, or you don’t want it public: Eventually send an email to (change the "a" to an "o").

Submitting an issue: Describe it as detailed as possible, eventually attach your autoexec and config.txt files. If autoexec.txt starts another batch file, include that also. A mere “My program won’t …” doesn’t help to come to a solution, how simple that even might be...
Note: MS SmartScreen stills flags this as rarely downloaded!