Sniff a MIDI Maze ring with a MIDI USB to PC adapter

[Hagane03]

Hello,

I´m trying to sniff the MIDI messages been sent in a MIDI ring between 2 Atari ST playing multiplayer MIDI Maze. When the ring is set with 2 MIDI cables everything is fine, one is the master the oter the slave. But when I change one of the cables for the USB adapter to get the messages in the ring with a MIDI monitor in my PC then both MIDI Maze Atari change to SLAVE .

So I would like to know if it´s posible to get with a monitor de messages been sent in a MIDI ring like that.

This is the adapter i´m using: https://www.amazon.es/music-editing-Con ... B01IOYXZKU

[sarnau]

MIDI Maze is not using the MIDI protocol to send data. It is a 8 bit data stream. If the interface in any way interprets it as MIDI, it will fail.

What are you trying to archive?

[ragnar76]

maybe, you can use hatari and tap the midi device. linux with socat should work

[1st1]

To sniff, you can watch on the Midi-IN on your PC, but don't expect classical MIDI data/protocol, Midimaze uses it's own data stream.

The trick is, that you have to connect the other cable from the PC to the other ST not to "OUT", but to "THRU". That depends on your MIDI-port device on your PC, not many MIDI interface for PC have it. THRU is just an electrical connection to IN, so there is no intelligence between them which could modify (or not forward) the data stream.

midielectric.gif

[sarnau]

I also do not think the protocol will really help: besides the Maze-Data being send around and Play/Stop/etc cases being handled, it is just a ring, which sends a single byte per computer in the ring containing the joystick data of that computer. So for 5 computers, you end up having 5 bytes with the current joystick status. Every computer then calculates all players based on that input (for computer players the joystick data is generated as well). So, if you try to do something exciting with it: that is probably not gonna work…

[1st1]

Maybe not joystick data, but coordinate in the maze and looking/moving direction. The same not only for the smileys, but also for the projectile. And also the number of hits for each user.

Note, that there is Midi Maze I, II and III, and they are different, maybe also in protocol.

[Hagane03]

To sniff, you can watch on the Midi-IN on your PC, but don't expect classical MIDI data/protocol, Midimaze uses it's own data stream.

The trick is, that you have to connect the other cable from the PC to the other ST not to "OUT", but to "THRU". That depends on your MIDI-port device on your PC, not many MIDI interface for PC have it. THRU is just an electrical connection to IN, so there is no intelligence between them which could modify (or not forward) the data stream.

midielectric.gif

Thank you. I think this is probably what im looking for, just to make sure my setup is like in the image. So if I want to sniff the data in the ring what I need is a software that let me enable MIDI-thru in my MIDI-in right? If so do you know os any software in Windows that allows it?

[ragnar76]

Maybe, this site here helps too. A lot of USB midi adapters are dangled together very cheaply https://karusisemus.wordpress.com/2017/ ... modify-it/

[1st1]

I need is a software that let me enable MIDI-thru in my MIDI-in right?

No, look at that example circuit diagram. Midi-Thru is hardware.

[gstoll]

Maybe not joystick data, but coordinate in the maze and looking/moving direction. The same not only for the smileys, but also for the projectile. And also the number of hits for each user.

Note, that there is Midi Maze I, II and III, and they are different, maybe also in protocol.

I think @sarnau know this.

https://github.com/sarnau/MidiMaze2

[sarnau]

Yes, you can trust me, when I say: MM1 and MM2 do never transmit any coordinates via MIDI. I actually did the coding for MM2 based on MM1.

At the start the maze data and the settings are transmitted plus a random seed value, so that all random decisions can be made in the identical way in all computers in the ring. After that only the joystick data is transmitted (and for MM2 also keyboard data), plus cancel, pause, etc (these have bit 7 set in the MIDI byte). All computers are taking all inputs and then calculate movement, etc. for all players and drones, which means there is no reason to transmit any additional data.

[Hagane03]

To sniff, you can watch on the Midi-IN on your PC, but don't expect classical MIDI data/protocol, Midimaze uses it's own data stream.

The trick is, that you have to connect the other cable from the PC to the other ST not to "OUT", but to "THRU". That depends on your MIDI-port device on your PC, not many MIDI interface for PC have it. THRU is just an electrical connection to IN, so there is no intelligence between them which could modify (or not forward) the data stream.

midielectric.gif

Thank you. I think this is probably what im looking for, just to make sure my setup is like in the image. So if I want to sniff the data in the ring what I need is a software that let me enable MIDI-thru in my MIDI-in right? If so do you know os any software in Windows that allows it?

Hello again. I´ve finally been able to make this kinda work, I can read the MIDI messages in the middle of the ring, more or less, becouse now my problem is that none of the MIDI Maze is the Master, both are Slaves, and if I read the message send by the MIDI Maze trying to be Master I get a "90 00 00" and even I Thru the message to the second Atari, the one supposed to be Slave, the Slave message disappears and the firts Atari keeps saying Slave, and neither of them is the Master. So I can start a game, with the PC in the middle to read the messages in the ring, and if I´m correct MIDI Maze doesn´t send MIDI messages, there are just Raw data.

So, my question would be if someone know what data MIDI Maze sends, in this case, to select a Master? And, why even though I´m using Thru something happens to my message?

Thank you