Sysex strings for controlling JD-800 tones

If you've spent time working with sysex on the Roland JD-800, you may have noticed that the tone layer/active buttons don't send sysex. This means, among other things, that if you are trying to turn tones on and off during a performance and record it with a sequencer, these actions will not be recorded.

There is, however, a sysex string that you can send to a JD-800 to turn tones on and off. Here is the string; it's expressed in bytes as two hexadecimal digits per byte (most software sequencers will allow you to copy and paste this into a sysex editing dialog box):

F0 41 10 3D 12 00 00 21 0x 5y F7

The x and y are variables. A byte-by-byte breakdown of the string:

• F0 The MIDI standard command byte that indicate that a sysex follows.
• 41 Roland's manufacturer ID.
• 10 The JD-800's unit number. The value "10" represents the factory default unit number of 17. If you have set your JD-800 to some other unit number, see the note at the end of this post.
• 3D The model number for the JD-800.
  
• 12 The command ID that tells the JD-800 to receive the following data.
• 00 00 21 The address of the tone layer parameter in the single-mode edit buffer.
  
• 0x is the parameter that tells the JD-800 which combination of tones should be on. The table below tells you how to set this value.
  
• 5y is a checksum, which the synth uses to check to see that the sysex string was transmitted correctly; if the checksum value is incorrect, the JD-800 will ignore the sysex. The table below tells you how to set this too.

Set the x and y values according to this table:
[apologies for the white space problem below; I haven't been able to fix it]

---

Tones On	X	Y
A	1	E
A, B	3	C
A, B, C	7	8
A, B, C, D	F	0
A, B, D	B	4
A, C	5	A
A, C, D	D	2
A, D	9	6
B	2	D
B, C	6	9
B, C, D	E	1
B, D	A	5
C	4	B
C, D	C	3
D	8	7

Sending the string turns on and off the selected combination of tones in the currently loaded patch. It only effects the edit buffer; it's exactly the same as pushing the buttons on the panel. The changes are not saved unless you write the patch to memory.

If you've changed your JD-800's unit number, you need to change the unit code in the sysex string. The JD-800 allows its unit number to be set to any value in the range 17-32. For unit number 17, the sysex code is 10, as show above. For unit 18, the code is 11; for unit 19, the code is 12, and so on... up to unit number 26, for which the code is 19. For unit 27, the code is 1A; for unit 28, the code is 1B, and so on... up to unit number 32, for which the code is 1F.