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MIDI Transport Controls

This page discusses the TNR’s baseline MIDI transport implementation, and some extensions.

Transport controls here cover the following messages

  • MIDI Start (0xFA)
  • MIDI Continue (0xFB)
  • MIDI Stop (0xFC)
  • MIDI Song Position Pointer (0xF2)
  • MIDI Block Change message

Behavior of Stock Firmware (v2.10)

The standard response to the MIDI transport controls is largely compliant to the MIDI specification.

Firstly, the messages that the TNR actually responds to, in slave or master mode, when the TNR is stopped or playing, is compliant. Here “Yes” means something happens, and “No” means nothing happens.

Message Slave Master
Name Byte Playing Stopped Playing Stopped
Start 0xFA No Yes2 No No
Continue 0xFB No Yes No No
Stop 0xFC Yes No No No
Song Position Pointer1 0xF2 No Yes No No

1: Song position pointer is interpreted as the playing position within the current block, not as a block change. The response to a SPP message of F2 0Y 00 is to set the playing position to Y. The last, MSByte, is ignored, which is always strange since this would have been a perfect vehicle for a block change byte.

2: The correct response to a “Start” message is to restart with song position 0, i.e. at the start of the block. However the TNR just treats Start the same as Continue

ASIDE : in Master mode, the TNR will produce Stop messages when stopped, and produce Start (FA) messages when started. This is non compliant - it should produce Continue (FB) messages when started since it doesn't restart from song position zero.

Behavior of New Firmware (releases since A025)

Several new features have been added to manage MIDI transport, allowing the TNR to become more non-compliant to the specification, but enabling better integration with DAWs and other MIDI transport aware hardware.

  1. MIDI Menu

    A new top-level MIDI menu has been created to manage global MIDI settings.

    MIDI menu

  2. MIDI Transport selection

    The response to any MIDI transport command can be now toggled between

    • “Off” : The TNR does not respond to ANY incoming transport MIDI messages. This includes FA/FB/FC. This is included to prevent the TNR responding to transport commands intended for other sequencers on the same MIDI bus.
    • “Slave” : The TNR only responds to incoming transport MIDI messages in Slave syncrhonisation mode. (This is the stock TNR behaviour)
    • “Master+Slave” : The TNR responds to incoming transport MIDI messages in Master and Slave syncrhonisation mode. This allows external stop/start control of the TNR while still using the TNR as the source of clock messages.
  3. Selection of Song Position Pointer Message Byte

    Not all sources can generate F3 song position pointer messages, so this option permits Control Change messages to be used instead, using any of CC 52-63 (usually indefined). Receipt of one of these CC messages on any midi channel is interpeted as a Song Position pointer. The encoding is the same as the LSByte of the SPP message, i.e. for CC 52 (0x34) this would now be be B0 34 0Y instead of F3 0Y 00

  4. Selection of Block Change Message Byte

    The block change message (See Block Change) can be changed from F3 to a CC message between 20-31.

  5. Song Position Pointer and Block Change messages work while playing

    Provided that SPP and BC messages are being listened to - i.e. Transport Mode is not Off and SPP and BC bytes are not OFF - then this feature means that the TNR will respond even when playing. (This was originally not allowed in the MIDI Specification because processing SPP messages could cause the synth to stutter and miss F8 clock messages, ending up out-of-time).

Together, this changes the table as follows:

Message Slave (assuming MIDI Transport is not set to "OFF") Master (assuming MIDI Transport is set to "Master+Slave")
Name Byte Playing Stopped Playing Stopped
Start 0xFA No Yes No Yes
Continue 0xFB No Yes No Yes
Stop 0xFC Yes No Yes No
Song Position Pointer 0xF2, or 0xBn 34-3F Yes Yes Yes Yes
Block Change Message 0xF3, or 0xBn 14-1F Yes Yes Yes Yes

Compatibility Issues

Previous settings files (including default) will default to the following setup:

Releases

First included in A023.

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Pika Blue is overly obsessed with midi controllers, especially unsupported ones with blinky lights .