Procedure TextMode(AL:Byte;BX,CX,DX:Word)

    Updates VX and VY       : Yes
    Updates Cursor Position : Always

    This calls the Set Video  Mode  BIOS  routine  with  the registers as
    specified.   Most  video  cards  use  only  AL  but  you  get the few
    weird SVGA card manufacturers who like to go overboard.