Int 21 Fn 06  - DOS 1+ - Direct Console Output                             [D]

   AH = 06h
   DL = character (except FFh)

Return: AL = character output (despite official docs which state nothing is
       returned) (at least DOS 3.3-5.0)

Notes: does not check  Break
   writes to standard output, which is always the screen under DOS 1.x,
     but may be redirected under DOS 2+

See Also: AH=02h,AH=09h