Int 2F Fn D001  C - Mdebug Display Driver - Initialize Driver              [G]

   AX = D001h

Return: CF set on error
   AL = driver semaphor
   AH = buffer semaphor
Range: AH=C0h to AH=FFh, selected by switch or programmatically

Notes: MDEBUG calls this function after every successful call of the function
     00h. The function should reset all internal data and the status of
     the driver. If this function returns an error, MDEBUG will not call
     the other functions in this popup session.
   MDEBUG can use any two consecutive multiplex numbers between C0h and
     FFh; the default is D0h for the display driver and D1h for the
     command driver

See Also: AX=D000h