Int E0  - Dr Multiuser Dos - "a_read" - Read Character From Default Aux D  [O]

   CL = 03h

Return: AL = ASCII character
   may destroy SI,DI???

Notes: A_READ reads the next 8-bit character from the logical auxilliary
     input device (AUXn:); control is not returned to the calling
     process until a character has been read.
   if another process owns AUX, this call blocks until the device becomes
     available
   this function is also supported by REAL/32

See Also: INT 21/AH=03h,INT E0/CL=04h,INT E0/CL=07h,INT E0/CL=A5h,INT E0/CL=ACh