Queues an I/O request to a channel associated with a network
    pseudodevice.
    The $QIO service is completed asynchronously; that is, it returns
    to the caller immediately after queuing the I/O request, without
    waiting for the I/O operation to be completed.
    For synchronous completion, use the Queue I/O Request and Wait
    ($QIOW) service. The $QIOW service is identical to the $QIO
    service, except the $QIOW returns to the caller after the I/O
    operation has completed.
    On Alpha and I64 systems, this service accepts 64-bit addresses.
    Format
      SYS$QIO  [efn],chan,func, [iosb],[astadr],[astprm],
               [p1],[p2],[p3],[p4], [p5],[p6]
    C Prototype
      int sys$qio  (unsigned int efn, unsigned short int chan,
                   unsigned int func, struct _iosb *iosb, void
                   (*astadr)(__unknown_params), __int64  astprm, void
                   *p1, __int64 p2, __int64  p3, __int64 p4, __int64
                   p5, __int64 p6);
    Returns
      OpenVMS usage:cond_value
      type:         longword (unsigned)
      access:       write only
      mechanism:    by value
    Longword condition value. All system services return (by
    immediate value) a condition value in R0. Condition values that
    can be returned by this service are listed under Condition Values
    Returned.