Roland SK-50 Owner's Manual page 55

* The resolution of 7-bit Hexadecimal numbers is 128. Use several bytes for values which require higher resolution.
i.e. The number "ad bbH" in 7-bit Hexadecimal is "ad x 128 + bb" in Decimal form.
* A signed number (with a sign +/-) is indicated as 00H = -64, 40H = 0, 7FH = +63.
So the signed number "aaH" in 7-bit Hexadecimal is "aa - 64" in Decimal form.
In the case of two bytes, it is regarded as 00 00H = -8192, 40 00H = 0, 7F 7FH = +8191.
So the signed number "aa bbH" in 7-bit Hexadecimal is "aa bbH - 40 00H = (aa x 128 + bb) - (64 x 128)" in Decimal form.
* The data indicated as "nibbled" is a 4-bit Hexadecimal number. i.e. "0a 0bH" is "a x 16 + b".
<Example 1>
<Example 2>
<Example 3>
<Example 4>
•Example of actual MIDI messages
<Example 1> 92 3E 5F
<Example 2> CE 49
<Example 3> EA 00 28
<Example 4> B3 64 00 65 00 06 0C 26 00 64 7F 65 7F
* To use running-status for several MIDI event like <example 4> in a song data (e.g. Standard MIDI File data) is not recommended. There may be a
sequencer which can not handle such data correctly when it is operated in fast forward or backward. Putting the status byte for every event is the
reliable way.
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Convert "5AH" in Hexadecimal to a Decimal number.
(By using the table) 5AH = 90
Convert "12 34H" in 7-bit Hexadecimal to a Decimal number.
(By using the table) 12H = 18, 34H = 52. So, 18 x 128 + 52 = 2356
Convert "0A 03 09 0D" in nibblized form to a Decimal number.
(By using the table) 0AH = 10, 03H = 3, 09H = 9, 0DH = 13, So, ((10 x 16 + 3) x 16 + 9) x 16 + 13 = 41885
Convert "1258" in Decimal form to a nibblized number.
16 )1258
16 ) 78...10
16 ) 4...14
0....4
(By using the table) 0 = 00H, 4 = 04H, 14 = 0EH, 10 = 0AH. So, 00 04 0E 0AH
"9n" is a status of a Note On message, and "n" is a MIDI channel number.
The second byte is the Note number, and the third is Velocity.
2H = 2, 3EH = 62, 5FH = 95
So, this is a Note On message of MIDI channel=3, Note number=62(D4) and Velocity=95.
"Cn" is a status of a Program change message, and "n" is a MIDI channel number.
The second byte is a Program number.
EH = 14, 49H = 73
So, this is a Program change message of MIDI channel=15, Program number= 74 (Flute in GS).
"EnH" is a status of a Pitch bend change message, and "n" is a MIDI channel number.
The second byte (00H) is an LSB and the third (28H) is an MSB of a Pitch bend value (Å}signed).
The Pitch bend value is :
28 00H - 40 00H = 40 x 128 + 0 - (64 x 128 + 0) = 5120 - 8192 = -3072
So, this is a Pitch bend change message of MIDI channel=11, Pitch bend value = -3072
If the Pitch bend sensitivity is set to 2 semitones, and the Pitch bend value -8192 (00 00H) is defined as -200 cents,
The actual pitch bend value of this message is :
-200 x (-3072) ÷ (-8192) = -75 cent
"Bn" is a status of a Control change message, and "n" is a MIDI channel number.
The second byte is a Control number and the third is the value.
This packet uses the running status rule, that is, when you send a series of messages with the same status,
you can omit the following status bytes.
This message contains :
B3 64 00 MIDI CH = 4 LSB of RPN parameter number
(B3) 65 00 MIDI CH = 4 MSB of RPN parameter number
(B3) 06 0C MIDI CH = 4 MSB of Data entry
(B3) 26 00 MIDI CH = 4 LSB of Data entry
(B3) 64 7F MIDI CH = 4 LSB of RPN parameter number
(B3) 65 7F MIDI CH = 4 MSB of RPN parameter number
This message string means 'send data "0C 00H" to RPN parameter number"00 00H", after that, set RPN parameter
number to "7F 7F"'.
RPN parameter number "00 00H" is Pitch bend sensitivity and the unit of the MSB value is a semitone, so 0CH = 12 is
a value to set the Pitch bend sensitivity = 12 semitones (one octave).
GS devices ignore the LSB value of Pitch bend sensitivity. However, you had better send both MSB and LSB(=00H) to
maintain data compatibility.
Once an RPN or NRPN number is set, all the Data entry messages sent after are effective.
Sometimes this rule may cause a problem if the MIDI data is played by a sequencer and it is operated in fast forward or
backward made. It is recommended, therefore, to set the RPN or NRPN number to 7F 7FH after sending the Data entry
messages.
: 00H
: 00H
: 0CH
: 00H
: 7FH
: 7FH