IIRC, Quake and Doom are DOS-based games.
Haven't kept up. Didn't play Quake Much. Didn't like it. I thought Doom was keeping up with the newer machines. Haven't played Doom in nearly a decade. I like Duke Nukem 3D, which is also a DOS based game if I remember correctly.
Even so, it implies it has all the DOS function calls, and a person can do a lot with that. I guess it's too much to ask that my DirectX/DirectPlay stuff will work.