Int E0  - Dr Multiuser Dos - "a_write" - Write Character To Default Aux D  [O]

   CL = 04h
   DL = BYTE to write

Return: nothing
   may destroy SI,DI,DH???

Note:  if another process owns AUX, this call blocks until the device becomes
     available

See Also: INT 21/AH=04h,INT E0/CL=03h,INT E0/CL=08h,INT E0/CL=A5h,INT E0/CL=ADh