If you are using the old Borland Turbo C ++ project (2.0 for DOS), this is a text file with the extension .PRJ. You can open it, like any text file (for example, test.c), and write all your files to it. Each line contains one .c or .cpp file with no extension, followed by its title in parentheses. for instance
mcalc (mcalc.h)
mcparser (mcalc.h)
mcdisply (mcalc.h)
...
mcalc.c #include "mcalc.h", PRJ.
, #include <stdio.h>, .PRJ.
, .c , , .PRJ .c .
PRJ . TC (Project- > Project name), .PRJ.
.