Am experimenting with Digital Research PLM86 (for DOS). I compiled a test program but when I try to run the .EXE file I get "Illegal CPU opcode 63 at 01D9:B63C4" and, having pressed "OK", Vdos just ends.
If you mean NTVDM which allows 16 bit programs to run under Windows 64 bit OS, I've never found this to work properly. I downloaded NTVDM x64 from the web site referenced in DOS Ain't Dead but I received a 'Threat' warning from my anti-virus software and could not therefore proceed.
I tried TEST1.EXE in Windows 32, but that didn’t run either because the program is just faulty. So something already went wrong at the compiling or linking stage. What program is produced if it is compiled in Windows 32. And what about older PLM86 programs that did run in Windows 32?
The only 32 bit OS I have is Windows XP as a virtual machine. Importing the PLM86 files into XP and running the compiled TEST1.EXE gives: "The NTVDM CPU has encountered an illegal instruction CS:0682 IP:00a6 OP:ff ff 0D 8a06". So I guess the compiler is producing dud code.