This test shows the use of RTAI distributed processing in user space.
It implements the sound example, found both in kernel space examples and in 
LXRT, on one/two machines. So you can have it played everywhere under control
of a remote process. The sound track is passed between tasks by using RTAI
extended messages. See example usound for an implementation based on a mailbox.

There are three speaker implementations: 
- one using generic rt_receivex/rt_returnx (speaker1.c);
- one using specific remote RT_receivex/RT_returnx (speaker2.c); 
- one using the optimized specific receive on the local stub (speaker3.c).

They aim at clarifying the technicalities explained in net_rpc/README.

To run them on a single machine do:

make
./run[1|2|3], or simply ./run to run them all, type ENTER to end
./rem, after ending it by pressing ENTER.

To run them on different machines comment out the line executing the process 
to be run on onother node, in files run/Run, and set the appropriate dotted
decimal notation IP address of the speaker task on its command line.
