Where to find the reference of dos.h for the c programming language?

I'm looking for the reference/documentation of the dos.h API. (especially for an openwa开发者_开发技巧tcom specific version).

Where to get the documentation?

One reasonable starting point would probably be the library documentation at OpenWatcom.

http://poli.cs.vsb.cz/c/help/dos.htm

Almost certainly not the original but a good resource anyway

Using the int 21h function reference widely available you could write your own DOS interface routine where the parameters are loaded into the appropriate registers inside the routine.

As I recall I needed three functions: one for character IO (byte register parameters), one for semi-complex (word register parameters - files, memory) and a third which I can no longer remember :(

It's a good exercise!