Queues an I/O request to a channel associated with a device. This
    service completes asynchronously; for synchronous completion, use
    the Queue I/O Request and Wait ($QIOW) service.

    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);