$QIOW

   The Queue I/O Request and Wait service queues an I/O request to a
   channel associated with a device.

   The $QIOW service completes synchronously; however, VSI
   recommends that you use an IOSB with this service to avoid
   premature completion.

   For asynchronous completion, use the Queue I/O Request ($QIO)
   service.

   In all other respects, $QIOW is identical to $QIO. For more
   information about $QIOW, refer to the description of $QIO.

   On Alpha and Integrity server systems, this service accepts 64-
   bit addresses.

   Format

     SYS$QIOW  [efn] ,chan ,func ,[iosb] ,[astadr]

               ,[astprm] ,[p1] ,[p2] ,[p3]

               ,[p4] ,[p5] ,[p6]

   C Prototype

     int sys$qiow  (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);