Filter
Top Products
19
MIDI Implementation
4. Supplementary Material
n
Decimal and Hexadecimal Table
(An “H” is appended to the end of numbers in hexadecimal notation.)
In MIDI documentation, data values and addresses/sizes of Exclusive messages, etc.
are expressed as hexadecimal values for each 7 bits.
The following table shows how these correspond to decimal numbers.
+------+------++------+------++------+------++------+------+
| D | H || D | H || D | H || D | H |
+------+------++------+------++------+------++------+------+
| 0 | 00H || 32 | 20H || 64 | 40H || 96 | 60H |
| 1 | 01H || 33 | 21H || 65 | 41H || 97 | 61H |
| 2 | 02H || 34 | 22H || 66 | 42H || 98 | 62H |
| 3 | 03H || 35 | 23H || 67 | 43H || 99 | 63H |
| 4 | 04H || 36 | 24H || 68 | 44H || 100 | 64H |
| 5 | 05H || 37 | 25H || 69 | 45H || 101 | 65H |
| 6 | 06H || 38 | 26H || 70 | 46H || 102 | 66H |
| 7 | 07H || 39 | 27H || 71 | 47H || 103 | 67H |
| 8 | 08H || 40 | 28H || 72 | 48H || 104 | 68H |
| 9 | 09H || 41 | 29H || 73 | 49H || 105 | 69H |
| 10 | 0AH || 42 | 2AH || 74 | 4AH || 106 | 6AH |
| 11 | 0BH || 43 | 2BH || 75 | 4BH || 107 | 6BH |
| 12 | 0CH || 44 | 2CH || 76 | 4CH || 108 | 6CH |
| 13 | 0DH || 45 | 2DH || 77 | 4DH || 109 | 6DH |
| 14 | 0EH || 46 | 2EH || 78 | 4EH || 110 | 6EH |
| 15 | 0FH || 47 | 2FH || 79 | 4FH || 111 | 6FH |
| 16 | 10H || 48 | 30H || 80 | 50H || 112 | 70H |
| 17 | 11H || 49 | 31H || 81 | 51H || 113 | 71H |
| 18 | 12H || 50 | 32H || 82 | 52H || 114 | 72H |
| 19 | 13H || 51 | 33H || 83 | 53H || 115 | 73H |
| 20 | 14H || 52 | 34H || 84 | 54H || 116 | 74H |
| 21 | 15H || 53 | 35H || 85 | 55H || 117 | 75H |
| 22 | 16H || 54 | 36H || 86 | 56H || 118 | 76H |
| 23 | 17H || 55 | 37H || 87 | 57H || 119 | 77H |
| 24 | 18H || 56 | 38H || 88 | 58H || 120 | 78H |
| 25 | 19H || 57 | 39H || 89 | 59H || 121 | 79H |
| 26 | 1AH || 58 | 3AH || 90 | 5AH || 122 | 7AH |
| 27 | 1BH || 59 | 3BH || 91 | 5BH || 123 | 7BH |
| 28 | 1CH || 60 | 3CH || 92 | 5CH || 124 | 7CH |
| 29 | 1DH || 61 | 3DH || 93 | 5DH || 125 | 7DH |
| 30 | 1EH || 62 | 3EH || 94 | 5EH || 126 | 7EH |
| 31 | 1FH || 63 | 3FH || 95 | 5FH || 127 | 7FH |
+------+------++------+------++------+------++------+------+
D:decimal
H:hexadecimal
* Decimal values such as MIDI channel, bank select, and program change are listed as
one greater than the values given in the above table.
* A 7-bit byte can express data in the range of 128 steps. For data where greater
precision is required, we must use two or more bytes. For example, two hexadecimal
numbers aa bbH expressing two 7-bit bytes would indicate a value of aa x 128+bb.
* In the case of values which have a +/- sign, 00H = -64, 40H = +/-0, and 7FH = +63,
so that the decimal expression would be 64 less than the value given in the above
chart. In the case of two types, 00 00H = -8192, 40 00H = +/-0, and 7F 7FH = +8191.
For example, if aa bbH were expressed as decimal, this would be aa bbH - 40 00H =
aa x 128 + bb - 64 x 128.
* Data marked “Use nibbled data” is expressed in hexadecimal in 4-bit units. A value
expressed as a 2-byte nibble 0a 0bH has the value of a x 16+b.
<Example 1> What is the decimal expression of 5AH?
From the preceding table, 5AH = 90
<Example 2> What is the decimal expression of the value 12 34H given as hexadecimal
for each 7 bits?
From the preceding table, since 12H = 18 and 34H = 52
18 x 128 + 52 = 2356
<Example 3> What is the decimal expression of the nibbled value 0A 03 09 0D?
From the preceding table, since 0AH = 10, 03H = 3, 09H = 9, 0DH = 13
((10 x 16 + 3) x 16 + 9) x 16 + 13 = 41885
<Example 4> What is the nibbled expression of the decimal value 1258?
16 ) 1258
16 ) 78 ...10
16 ) 4 ...14
0 ... 4
Since from the preceding table, 0 = 00H, 4 = 04H, 14 = 0EH, 10 = 0AH, the result is: 00
04 0E 0AH.
n
Examples of Actual MIDI Messages
<Example 1> 92 3E 5F
9nH 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 with MIDI CH = 3, note number 62 (note name
is D4), and velocity 95.
<Example 2> CE 19
CnH is the Program Change status, and n is the MIDI channel number. Since EH = 14
and 19H = 25, this is a Program Change message with MIDI CH = 15, program number
26.
<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 and the 3rd byte (28H = 40) is the MSB, but Pitch Bend Value is a
signed number in which 40 00H (= 64 x 12 + 80 = 8192) is 0, so this Pitch Bend Value is
28 00H - 40 00H = 40 x 12 + 80 - (64 x 12 + 80) = 5120 - 8192 = -3072
If the Pitch Bend Sensitivity is set to 2 semitones, -8192 (00 00H) will cause the pitch to
change -200 cents, so in this case -200 x (-3072) ÷ (-8192) = -75 cents of Pitch Bend is
being applied to MIDI channel 11.