Int E0  - Dr Multiuser DOS - "a_attach" - Attach Aux Device                [O]

   CL = A5h
Desc:  attaches the default auxiliary device to the calling process unless
     it is already attached to another process, in which case the call
     blocks until the device becomes available

Note:  this call should be used before attempting to read or write from
     the AUX device; however, the I/O calls internally call this function
     to ensure device ownership

See Also: INT E0/CL=03h,INT E0/CL=04h,INT E0/CL=A6h,INT E0/CL=A7h,INT E0/CL=A8h

See Also: INT E0/CL=ACh,INT E0/CL=ADh,INT E0/CL=B0h