The way I remember FlightSim (from first official PC clone presentation, compaq in 1982! https://www.youtube.com/watch?v=7THrlGIL9k0 https://www.youtube.com/wa

The way I remember FlightSim (from first official PC clone presentation, compaq in 1982! https://www.youtube.com/watch?v=7THrlGIL9k0 https://www.youtube.com/watch?v=7THrlGIL9k0 ) was that it jumped directly to raw hardcoded pointers in the bios instead of calling interrupts. Another "test" was WordStar? using DOS/BIOS CP/M compatibility layer (afaik the only software ever to do that?). There were also programs expecting MS basic in the rom.