Roland JP-8080 Owner's Manual page 206

5. Supplementary material
Decimal/Hexadecimal table
(hexadecimal values are indicated by a following "H")
MIDI uses 7-bit hexadecimal values to indicate data values and the address and size of
exclusive messages. The following table shows the correspondence between decimal and
hexadecimal numbers.
+——————+——————++——————+——————++——————+——————++——————+——————+
| D | H || D | H
+——————+——————++——————+——————++——————+——————++——————+——————+
| 0 | 00H || 32 | 20H ||
| 1 | 01H || 33 | 21H ||
| 2 | 02H || 34 | 22H ||
| 3 | 03H || 35 | 23H ||
| 4 | 04H || 36 | 24H ||
| 5 | 05H || 37 | 25H ||
| 6 | 06H || 38 | 26H ||
| 7 | 07H || 39 | 27H ||
| 8 | 08H || 40 | 28H ||
| 9 | 09H || 41 | 29H ||
| 10 | 0AH || 42 | 2AH ||
| 11 | 0BH || 43 | 2BH ||
| 12 | 0CH || 44 | 2CH ||
| 13 | 0DH || 45 | 2DH ||
| 14 | 0EH || 46 | 2EH ||
| 15 | 0FH || 47 | 2FH ||
| 16 | 10H || 48 | 30H ||
| 17 | 11H || 49 | 31H ||
| 18 | 12H || 50 | 32H ||
| 19 | 13H || 51 | 33H ||
| 20 | 14H || 52 | 34H ||
| 21 | 15H || 53 | 35H ||
| 22 | 16H || 54 | 36H ||
| 23 | 17H || 55 | 37H ||
| 24 | 18H || 56 | 38H ||
| 25 | 19H || 57 | 39H ||
| 26 | 1AH || 58 | 3AH ||
| 27 | 1BH || 59 | 3BH ||
| 28 | 1CH || 60 | 3CH ||
| 29 | 1DH || 61 | 3DH ||
| 30 | 1EH || 62 | 3EH ||
| 31 | 1FH || 63 | 3FH ||
+——————+——————++——————+——————++——————+——————++——————+——————+
D: decimal
H: hexadecimal
* Decimal expressions such as used for MIDI channel, Bank Select, and Program Change
will be the value 1 greater than the decimal value given in the above table.
* Since each MIDI byte carries 7 significant data bits, each byte can express a maximum
of 128 different values. Data for which higher resolution is required must be transmit-
ted using two or more bytes. For example a value indicated as a two-byte value of aa
bbH would have a value of aa x 128 + bb.
<Example 1>
What is the decimal equivalent of 5AH?
From the above table, 5AH = 90.
<Example 2>
What is the decimal equivalent of the 7-bit hexadecimal values 12 34H?
From the above table, 12H = 18 and 34H = 52
Thus, 18 x 128 + 52 = 2356
Examples of actual MIDI messages
<Example 1> 92 3E 5F
9n is the Note On status and 'n' is the MIDI channel number. Since 2H = 2, 3EH = 62, and
5FH = 95, this is a Note On message of MIDI CH = 3, note number 62 (note name D4) and
velocity 95.
<Example 2> CE 49
CnH is the Program Change status and 'n' is the MIDI channel number. Since EH = 14,
and 49H = 73, this is a Program Change message of MIDI CH = 15, Program number 74
(in the GS sound map, Flute).
<Example 3> EA 00 28
EnH is the Pitch Bend Change status and 'n' is the MIDI channel number. The 2nd byte
(00H=0) is the LSB of the Pitch Bend value, and the 3rd byte (28H=40) is the MSB.
However since the Pitch Bend is a signed number with 0 at 40 00H ( = 64 x 128 + 0 = 8192),
the Pitch Bend value in this case is
28 00H - 40 00H = 40 x 128 + 0 - (64 x 128 + 0) = 5120 - 8192 = -3072
If we assume that the Pitch Bend Sensitivity is set to two semitones, the pitch will change
only -200 cents for a Pitch Bend value of -8192 (00 00H). Thus, this message is specifying a
Pitch Bend of -200 x (-3072) / (-8192) = -75 cents on MIDI CH = 11.
206
|| D | H || D | H
64 | 40H || 96 | 60H |
65 | 41H || 97 | 61H |
66 | 42H || 98 | 62H |
67 | 43H || 99 | 63H |
68 | 44H || 100 | 64H |
69 | 45H || 101 | 65H |
70 | 46H || 102 | 66H |
71 | 47H || 103 | 67H |
72 | 48H || 104 | 68H |
73 | 49H || 105 | 69H |
74 | 4AH || 106 | 6AH |
75 | 4BH || 107 | 6BH |
76 | 4CH || 108 | 6CH |
77 | 4DH || 109 | 6DH |
78 | 4EH || 110 | 6EH |
79 | 4FH || 111 | 6FH |
80 | 50H || 112 | 70H |
81 | 51H || 113 | 71H |
82 | 52H || 114 | 72H |
83 | 53H || 115 | 73H |
84 | 54H || 116 | 74H |
85 | 55H || 117 | 75H |
86 | 56H || 118 | 76H |
87 | 57H || 119 | 77H |
88 | 58H || 120 | 78H |
89 | 59H || 121 | 79H |
90 | 5AH || 122 | 7AH |
91 | 5BH || 123 | 7BH |
92 | 5CH || 124 | 7CH |
93 | 5DH || 125 | 7DH |
94 | 5EH || 126 | 7EH |
95 | 5FH || 127 | 7FH |
<Example 4> B3 64 00 65 00 06 0C 26 00 64 7F 65 7F
BnH is the Control Change status, and 'n' is the MIDI channel number. In Control Change
messages, the 2nd byte is the controller number, and the 3rd byte is the parameter value.
MIDI allows what is known as "running status," when if messages of the the same status
follow each other, it is permitted to omit the second and following status bytes. In the
message above, running status is being used, meaning that the message has the following
content.
B3 64 00 MIDI CH = 4, RPN parameter number LSB:
(B3) 65 00 MIDI CH = 4, RPN parameter number MSB:
(B3) 06 0C MIDI CH = 4, parameter value MSB:
|
(B3) 26 00 MIDI CH = 4, parameter value LSB:
(B3) 64 7F MIDI CH = 4, RPN parameter number LSB:
(B3) 65 7F MIDI CH = 4, RPN parameter number MSB:
Thus, this message transmits a parameter value of 0C 00H to RPN parameter number 00
00H on MIDI CH = 4, and then sets the RPN parameter number to 7F 7FH.
The function assigned to RPN parameter number 00 00H is Pitch Bend Sensitivity, and the
MSB of the parameter value indicates semitone steps. Since the MSB of this parameter
value is 0CH = 12, the maximum width of pitch bend is being set to -/+12 semitones (1
octave) (GS sound sources ignore the LSB of Pitch Bend Sensitivity, but it is best to trans-
mit the LSB (parameter value 0) as well, so that the message can be correctly received by
any device.
Once the parameter number has been set for RPN or NRPN, all subsequent Data Entry
messages on that channel will be effective. Thus, it is recommended that after you have
made the change you want, you set the parameter number to 7F 7FH (an 'unset' or 'null'
setting). The final (B3) 64 7F (B3) 65 7F is for this purpose.
It is not a good idea to store many events within the data of a song (e.g., a Standard MIDI
File song) using running status as shown in <Example 4>. When the song is paused, fast-
forwarded or rewound, the sequencer may not be able to transmit the proper status, caus-
ing the sound source to misinterpret the data. It is best to attach the proper status byte to
all events.
It is also important to transmit RPN or NRPN parameter number settings and parameter
values in the correct order. In some sequencers, data events recorded in the same clock (or
a nearby clock) can sometimes be transmitted in an order other than the order in which
they were recorded. It is best to record such events at an appropriate interval (1 tick at
TPQN=96, or 5 ticks at TPQN=480).
* TPQN :Ticks Per Quarter Note (i.e., the time resolution of the sequencer)
Examples of exclusive messages and calculating the checksum
Roland exclusive messages (RQ1, DT1) are transmitted with a checksum at the end of the
data (before F7) to check that the data was received correctly. The value of the checksum
is determined by the address and data (or size) of the exclusive message.
How to calculate the checksum
(hexadecimal values are indicated by a 'H')
The checksum consists of a value whose lower 7 bits are 0 when the address, size and
checksum itself are added.
The following formula shows how to calculate the checksum when the exclusive message
to be transmitted has an address of aa bb cc ddH, and data or size of ee ffH.
aa + bb + cc + dd + ee + ff = total
total / 128 = quotient ... remainder
128 - remainder = checksum
<Example 1>
Setting the Temporary Performance Upper Part Transpose to +5 (DT1).
The "Parameter address map" indicates that the starting address of the Temporary
Performance is 01 00 00 00H, that Temporary Performance upper Part offset address is 10
00H, Part Transpose is 00 03H. Thus,the adress is:
01 00 00 00H
10 00H
+) 00 03H
01 00 10 03H
Since +5 is parameter value 1DH,
F0 41 10
(1) (2) (3)
(1) Exclusive status
(4) model ID (JP-8080)
00 06 12 01 00 10 03 1D
(4) (5) address data
(2) ID number (Roland) (3) device ID (17)
(5) command ID (DT1) (6) EOX
00H
00H
0CH
00H
7FH
7FH
F7
??
checksum (6)