Function            set_mode - set the video mode

  Syntax              void set_mode(byte mode);

  Prototype in        video.h

  Remarks             sets the video mode via INT 0x10, Service 0.

  Return value        nothing.

  See also            video.h
                      read_mode()

  Example             #include <video.h>

                      main()
                      {
                           set_mode(3);        /* text mode */
                           printf("# columns: %d    Mode: %d   Page:
                                %d\n", width, mode, page);
                      }

  Program output      # columns: 80    Mode: 3   Page: 1