- The Epigraf Protocol Specialist

This area describes many procedures necessary to implement the secrets revealed by the Media Magician. Since many procedures are used over and over again in various contexts, they are collected here so as to avoid clogging up the magic with a bunch of techno babbo.

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Sending (transmitting) System Exclusive Messages

In sending a System Exclusive Message to a MIDI device, the following must be considered.

1. The Method of Creation and Where do I Put It Once I've Created It?
   • The "Method" will most likely be a command within a computer-based MIDI sequencer program which provides for entering a series of numbers.

   • The "Where do I Put It" question is answered by knowing that Sysex messages can be saved and retrieved within a MIDI sequencer program. After all of the numbers have been entered and checked for accuracy, a System Exclusive Message Transmission occurs in response to another command or button available within the MIDI sequencer program. Because System Exclusive Messages provide access to such specialized parts of the equipment to which they are sent, it is important to be careful when composing a System Exclusive Message. A missed, or errant number in the series can cause unexpected results and inadvertant change/loss of data in the intended device.

2. The Numbering System required. There are two common methods of representing numbers within MIDI devices. Hexadecimal, or Hex for short, is the most common format.

3. All System Exclusive messages begin with a first command byte of F0.

4. All System Exclusive messages continue with a short sequence of either one or three bytes which identify the manufacturer of the intended MIDI device. This is called the Manufacturer's ID. The length (one or three bytes) is determined by the following two rules:
   • If the first byte following the F0 does not equal 0, then the manufacturer's ID is a single byte.

   • If the first byte following the F0 does equal 0, then the manufacturer's ID is 3 bytes long, including the first byte which equals 0. In this case, the second and third bytes are the ones of interest.

5. Whatever bytes follow are totally up to each manufacturer.

6. The only restriction is that an F7 byte which means End Of eXclusive message, or EOX, for short, should be the final byte of the System Exclusive Command.