wn_scroll -- set scrolling method for window

        USAGE

          wn_scroll(wn,method)
          WINDOWPTR wn;
          int method;

                  wn -      window handle.
                  method -  BIOS or DMAS

           Set the method to be used to scroll the contents of the window
           to use either the rom bios (BIOS), or the flicker free DMA
           logic.  BIOS and DMAS are defined in "windows.h".

           The default scrolling mode is DMAS.

           The Window BOSS incorporates machine independent logic that
           ensures that scrolling on color systems is performed in such a
           way as to totally eliminate snow and flicker.  This logic,
           although bulletproof, can slow scrolling down.  Setting the
           scrolling method to BIOS provides a machine independent way to
           improve the scrolling speed with a (perhaps) proportional
           increase in flicker.  Keep in mind that recent developments in
           CGA and EGA technology have, for the most part, eliminated
           scrolling flicker at the hardware level.  If your system is
           equipped with one of these boards, you may achieve a
           noticeable improvement in scrolling speed by using wn_scroll()
           to set the scrolling method to BIOS.  Additionally, there are
           several console device drivers (FANSI and NANSI to mention
           two) that "patch" the bios routines to achieve the same
           result.

           Setting the scrolling method to BIOS when wn_dmaflg=FALSE has
           no effect.

        RETURNS

           Nothing.

        CAUTIONS

           Color systems only.