NAME: TextMode

     USE: Sets the screen to the specified textmode.  Valid values
          are:

         Constant     Adapter       Color or B&W    Screen Size
         --------     -------       ------------    -----------

         BW40  = 0;   Color         Black/White     40 X 25
         C40   = 1;   Color         Color           40 X 25
         BW80  = 2;   Color         Black/White     80 X 25
         C80   = 3;   Color         Color           80 X 25
         MONO  = 7;   Monochrome    Black/White     80 X 25

         Last  = -1;  Last active text mode


     DEPENDENCY:  The CRT unit must be used placed in the uses section.

     SYNTAX: TextMode(ModeRequest : Integer);