Never mind, it turns out the function keys DO work in Clipper programs. It was just a TSR started by a particular Clipper program that was causing havoc. 😊

Yes, they work in other dos programs just fine.

I have several old Clipper programs that I would like to run in DosBox. But for some unknown reason, the function keys do not work in a Clipper program. Is this a known problem? Any way to solve this?

Too bad. There's a large amount of old business software for DOS out there that use this "dual" monitor setup. Like I said, many old C Developer Kits (like Watcom and Microsoft SDK) for instance, as well as some CAD programs.

I have several old DOS programs that use two graphics adapters at once. A VGA card is always used as the "primary" adapter and the Hercules cards as the "secondary". For instance, several old C compilers had the option of showing debug information on the second (Hercules) adapter. How all these …