MMC

MMC is part of the Universal Real-Time System Exclusive protocol. Various SysEx messages have been implemented to take advantage of MMC. Commands and Responses

MIDI MACHINE CONTROL MMC MIDI Machine Control (MMC) was designed so that a MIDI system could remotely control hardware that is usually used for recording and playing back audio and/or video.

MIDI MACHINE CONTROL MMC

MIDI MACHINE CONTROL MMC A sequencer program can start, stop, fast forward, etc. a tape deck, video deck, or other hardware device. You don’t have to physically reach over to the hardware.

MIDI MACHINE CONTROL MMC

Every device that is MMC compatible has a unique ID number (1-128).

Each MMC device (tape deck, video deck, drum machine, etc) should be assigned to its own ID number so that each device can be individually controlled.

The sequencer can also have an ID so that a tape deck can control the record/playback of the sequencer.

A computer is not required to incorporate MMC. A multiple modular recorder setup (multiple DA38s, Adats, etc.) also may make use of MMC to control the devices. id: 1 2 3

If two or more devices have the same ID number, both units will respond to the same MMC commands.

Some devices can respond to multiple ID numbers.

ID number 127 is referred to as the “All-Call ID Number”.

MMC commands sent with this ID will control all MMC devices in the set-up regardless of their unique ID number (if they are programmed to do so).

It is also possible to create a group ID number that represents multiple devices.

This means that a single command can be sent to specific a group of devices instead of a message for each device.

There are two types of MMC messages: o Command o Response

It is possible to ask an MMC device for its identity. To do so, you send the device an ID Request message. The reply is device/manufacturer specific.

Parts of ID message:  Device's ID  Device's family code  Device's family number  Software Version

MMC Handshake closed loop VS open loop Most MMC devices when turned on determine if there is two-way communication (closed-loop) or one-way communication (open loop).

MMC Handshake closed loop VS open loop open

MMC Handshake closed loop VS open loop closed

MMC Handshake closed loop VS open loop If a device doesn’t detect a closed- loop, it assumes that it will only send or receive MMC commands rather than doing both.

MMC Handshake closed loop VS open loop If the device receives a ‘hand- shake’, it assumes that it can do both, transmit and respond to MMC commands and responses.

MMC works with MTC / MIDI Clock / Etc The Goto MMC message The Goto message cues recording or playback to a SMPTE time (a specific hour, minute, second, SMPTE frame number, and subframe number) SPP can be used.

Identity Request Query an MMC device to find out its identity. Identity Request message (note that this is equal to a 'stop' message)

The Record Ready MMC message The Record Ready (Arm Tracks) message will record-enable tracks

MMC MESSAGES Classified by type: Comm: Communications Ctrl: Transport (play - stop - etc.) Evnt: Event Gen: Time Codes I/O: Reading, writing Sync: Synchronization

MMC Messages (cont.) Math: Mathematical operations MTC: MIDI Time Code Proc: Procedures Time: info dealing with time code

07 Record Exit (Punch out) 08 Record Ready 09 Pause 0A Eject 0F MMC Reset 40 Write 44 Locate/Go to

controls 01 Stop 02 Play 03 Deferred Play 04 Fast Forward 05 Rewind 06 Record Strobe (Punch In)

08 Record Ready 09 Record Pause 0A Eject 0B Chase (Sync) 0C Command Error Reset (I/O) 0D MMC Reset

40 Write (I/O) 42 Read 43 Update 44 Locate 46 Search 47 Shuttle

48 Step 4A GENERATOR COMMAND 4B MTC Command 4C Move (math affects time code) 4D Add (math affects time code) 4E Subtract (math affects time code) 4F Drop Frame Adjust (math affects time code)

63H VITC insert enable 65H Failure 7CH Wait 75H Resume

MMC RESPONSES record status track record status track record ready play speed reference (internal or external) chase mode event response (did it do the command) failure wait

MIDI SHOW CONTROL MSC all types of entertainment control devices to talk with each othe

MIDI SHOW CONTROL MSC go stop resume timed_go load set fire all_off restore reset go_off

MIDI SHOW CONTROL MSC The first show to fully utilize the MSC specification was the Magic Kingdom Parade at Walt Disney World's Magic Kingdom in September 1991

Other Messages ACK NAK Cancel Wait End of File (EOX)