Int 15 Fn 0B  - Multidos Plus - Force Display Output To Physical Screen M  [T]

   AH = 0Bh

Notes: sets calling task's screen pointer to actual screen memory; the pointer
     may be restored with AH=0Ch
   caller's video mode must be same as foreground task's video mode
   any text written while in the background will be saved to the
     foreground task's virtual screen when it switches to the background
   useful if a background task wants to display a message on the
     foreground screen

See Also: AH=0Ch"MultiDOS"