I think we got off subject
I think I know where the original post was getting at.
Estranged, all you would need is to make a header file containing all the prototypes for the functions your source files will contain. For example:
main.c - source file containing your main "function"
sprites.c - source file for sprite functions
sprites.h - header file with all prototype for sprite functions
video.c - source file for video functions
video.h - header file for video prototypes
You will be including sprites.h and video.h in your main.c. Include all "sub" headers in your sources. For example, video.h will be included in video.c.
Using turbo c v.2.01, all you would need to link this at the command line: (NOTE: This compile will compile sources to object files, pass them to the linker, and generate 80286 compatible instructions using a huge memory model ;-) )
TCC -l-c -2 -mm -w main.c sprites.c video.c mathm.lib cm.lib graphics.lib emu.lib fp87.lib
Download a few sources off the net to see what I'm talking about. Programmer's Heaven has a lot of game sources that can be compiled with the same example above, including a nice Bomberman clone ;-)