Supplementary material, System realtime message, System exclusive message – Edirol PC-80 User Manual

Page 128: Midi implementation

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128

MIDI implementation

System realtime message

Timing Clock

Status
F8H

*

Transmitted if the System setting F8 CLOCK is ON.

Start

Status
FAH

Continue

Status
FBH

Stop

Status
FCH

Active sensing

Status
FEH

*

Transmitted at intervals of approximately 250 ms.

System exclusive message

GM2 System On

Status

Data byte

Status

F0H

7EH 7FH 09H 03H

F7H

Byte

Explanation

F0H

Exclusive status

7EH

ID number (Universal Non-realtime Message)

7FH

Device ID (Broadcast)

09H

Sub ID#1 (General MIDI Message)

03H

Sub ID#2 (General MIDI 2 On)

F7H

EOX (End Of Exclusive)

2. Supplementary material

Decimal and Hexadecimal table

(An “H” is appended to the end of numbers in hexadecimal notation.)

In MIDI documentation, data values are expressed as hexadecimal values for each 7
bits.
The following table shows how these correspond to decimal numbers.

fig.11-22e

*

The decimal expression of the MIDI channel, program change, etc., is one greater
than the decimal value shown in the table above.

*

The hexadecimal expression for each 7 bits allows a maximum of 128 steps (0–
127) to be expressed by one byte of data. Multiple bytes are used if the data
requires greater resolution than this. For example, a value expressed by two 7-bit
bytes “aa” and “bbH” would be aa x 128 + bb.

*

In the case of signed (+/-) data, 00H = -64, 40H = +/-0, and 7FH = +63; i.e., a
value 64 less than the decimal value shown in the above table is used. In the case
of a two-byte value, 00 00H = -8192, 40 00 = +/-0, and 7F 7F = +8191. For
example, a value of “aa” and “bbH” would have a decimal expression of aa bbH
- 40 00H = aa x 128 + bb - 64 x 128.

<Example1>

What is the decimal expression of 5AH?
From the preceding table, 5AH = 90.

<Example2>

What is the decimal expression of the 7-bit hexadecimal value 12 34H?
From the preceding table, 12H = 18, and 34H = 52.
Thus, this is

18 x 128 + 52 = 2356

Dec.

Hex.

Dec.

Hex.

Dec.

Hex.

Dec.

Hex.

0
1
2
3
4
5
6
7
8
9

10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

00H
01H
02H
03H
04H
05H
06H
07H
08H
09H

0AH
0BH

0CH
0DH

0EH

0FH

10H
11H
12H
13H
14H
15H
16H
17H
18H
19H

1AH
1BH

1CH
1DH

1EH

1FH

32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63

20H
21H
22H
23H
24H
25H
26H
27H
28H
29H

2AH
2BH

2CH
2DH

2EH

2FH

30H
31H
32H
33H
34H
35H
36H
37H
38H
39H

3AH
3BH

3CH
3DH

3EH

3FH

64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95

40H
41H
42H
43H
44H
45H
46H
47H
48H
49H

4AH
4BH

4CH
4DH

4EH

4FH

50H
51H
52H
53H
54H
55H
56H
57H
58H
59H

5AH
5BH

5CH
5DH

5EH

5FH

96
97
98
99

100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127

60H
61H
62H
63H
64H
65H
66H
67H
68H
69H

6AH
6BH

6CH
6DH

6EH

6FH

70H
71H
72H
73H
74H
75H
76H
77H
78H
79H

7AH
7BH

7CH
7DH

7EH

7FH

PC-80_e.book 128 ページ 2005年11月10日 木曜日 午前11時34分

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