NAME
       AbortIO - abort a device command

   SYNOPSIS
       AbortIO(iORequest);
                   A1

   FUNCTION
       AbortIO tries to abort a device command.  It is allowed to be
       unsuccessful.  If the Abort is successful, the io_Error field of the
       iORequest contains an indication that IO was aborted.

   INPUTS
       iORequest -- pointer to the I/O request for the command to abort