There really isn't any tutorial that I know of. Not many people have used it. I have used it before though, but only in a way that supports 2 player multiplayer and it is buggy too.
I would say take a look at the code, but the code for PONG 3D is impossible to read as I didn't really make it to be readable, just efficient.
Also you'll need a 2nd system for testing purposes if you don't have 1.
'If all you want to do is send a message then:
MPSTART 'One person says yes, the other no
IF MPLOCAL==MPHOST THEN'If true you are the host system
MPSEND "HELLO OTHER WORLD!" 'send a text string
WAIT 398'waiting to insure enough time to read
MPEND
ELSE 'when not host
WHILE(MES$=="")
MPRECV OUT MPHOST,MES$ 'Get a message from the host & store MES$
WEND
PRINT MES$
ENDIF
You can do a lot more than send messages, if you set several variables for X and Y of other players, you can make a truly interactive world. But that's just basics, there's still a whole lot more than players and messages, once you put in the effort and work, you can make a truly marvelous multiplayer experience.
I just figured you were trying to send a message because of the screenshot you provided. You have 9 slots of shareable integer data with MPSET and MPGET. Buttons and the circle pad have built in methods to share key presses, so don't worry about that.
