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Setting the sysex data format, Checksum format – Apple Logic Pro 7 User Manual

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258

Chapter 5

The Environment

The first data byte in the top line (directly after the word SysEx in the “NUM” column)
is the manufacturer’s ID. This may be several data bytes long (as there are more than
128 manufacturers of MIDI devices).

The manufacturer’s ID is usually followed by a device type ID, an individual device ID,
a data type ID (which could be several bytes) and, if necessary, the number of the
multi-timbral sub channel, the identification number(s) of the sound parameters plus
the value of the sound parameter. There are no uniform “standards” that apply here.

Data bytes are normally input as decimal numbers. To enter them in hex, place a “$”
in front of values when you type them in. View > SysEx in Hex Format allows you to
see all values in hexadecimal.

The last data byte (the “EOX” indicating the end of the SysEx message) is entered
automatically by Logic. The number of data bytes in the SysEx message can be
decreased or increased by clicking one of the two arrows before and after the word
”.

Although you can have any number of messages (of any kind) in the SysEx fader’s
event list there is only one fader value, and all selected messages will adopt this value.

You can use a similar method to create any kind of MIDI or meta event in the SysEx
fader window. Command-clicking any of the eight event type buttons (note, program
number, pitch bend, controller, channel pressure, poly pressure, SysEx, and meta event)
creates a new event of that type. Meta events can be created by using the expanded
view button—featuring the 0’s and 1’s on it’s face.

Setting the SysEx Data format

The terms “SUM” for the checksum and “VAL” for the fader value being sent are
displayed within the SysEx string. The position and format of these bytes are set from
the “Checksum”, “Value” and “Position” pull-down menus. These settings may be found
in the lower left-hand corner of the fader event list.

Only selected SysEx events are affected by the above parameters, because only these
events are affected by the fader value.

Checksum format

A checksum can be created in any of the following formats:

Roland

Yamaha

Regular Checksum