Question:
These old DOS programs run really slowly, hog all of Windows resources.
Answer:
Use TameDOS (
www.tameDOS.com). It costs $20 bucks, you get a 30 day free trial first. It will solve all your problems with DOS misbehaving under WinXP and earlier Windows version.
I can run several DOS apps (e.g. multiple copies of Spec, Val, on different directories) at the same time, with no loss of speed.