When mounting multiple floppy images using imgmount, they're not bootable and also not visible inside a booted system. From what I can tell, the imageDiskList[0] is only created when 1 image is mounted (dos_programs.cpp:1296) so the check at line 663 fails when boot is later called. Inside DOS, you get 'General failure reading drive A'. Mounting images using boot command works as expected.

Also, inside the 'if (paths.size() == 1)' check (dos_programs.cpp:1296), the code would be somewhat more readable if 'else' was used instead of 2 'if's checking for the same thing and the other one negating it 😀