How to calculate the checksum (hexadecimal numbers are indicated by 'H') The checksum is a value derived by adding the address, size and checksum itself and inverting the lower 7 bits.
Here's an example of how the checksum is calculated. We will assume that in the exclusive message we are transmitting, the address is aa bb ccH and the data or size is dd ee ffH.
aa+bb+cc+dd+ee+ff = sum
sum ⎟ 128 = quotient ... remainder 128 - remainder = checksum
<Example 1> Setting REVERB MACRO to ROOM 3
According to the "Parameter Address Map," the REVERB MACRO Address is 40 01 30H, and ROOM 3 is a value of 02H. Thus,
F0 | 41 | 10 | 42 | 12 | 40 01 30 | 02 | ?? | F7 |
(1) | (2) | (3) | (4) | (5) | address | data | checksum | (6) |
(1) | Exclusive Status, | (2) | ID (Roland), | (3) | Device ID (17), |
| ||
(4) | Model ID (GS), | (5) | Command ID (DT1), | (6) | End of Exclusive | |||
Next we calculate the checksum.
40H+01H+30H+02H = 64+1+48+2 = 115 (sum) 115 (sum) ⎟ 128 = 0 (quotient) ... 115 (remainder) checksum = 128 - 115 (remainder) = 13 = 0DH
This means that F0 41 10 42 12 40 01 30 02 0D F7 is the message we transmit.
<Example 2> Requesting transmission of the LEVEL for DRUM MAP 1 NOTE NUMBER 75 (D#5; Claves)
NOTE NUMBER 75 (D#5) is 4BH in hexadecimal.
According to the "Parameter Address Map," LEVEL of NOTE NUMBER 75 (D#5; Claves) in DRUM MAP 1 has an Address of 41 02 4BH and a Size of 00 00 01H. Thus,
F0 | 41 | 10 | 42 | 11 | 41 02 4B 00 00 01 | ?? | F7 | ||
(1) | (2) | (3) | (4) | (5) | address | size |
| checksum | (6) |
(1) | Exclusive Status, | (2) | ID (Roland), | (3) | Device ID (17), |
| |||
(4) | Model ID (GS), | (5) | Command ID(RQ1), | (6) | End of Exclusive | ||||
Next we calculate the checksum.
41H+02H+4BH+00H+00H+01H = 65+2+75+0+0+1 = 143 (sum) 143 (sum) ⎟ 128 = 1 (quotient) ... 15 (remainder)
checksum = 128 - 15 (remainder) = 113 = 71H
This means that F0 41 10 42 11 41 02 4B 00 00 01 71 F7 is the message we trans- mit.
●About tuning
In MIDI, individual Parts are tuned by sending RPN #1 (Master Fine Tuning) to the appropriate MIDI channel.
In MIDI, an entire device is tuned by either sending RPN #1 to all MIDI channels being used, or by sending a System Exclusive MASTER TUNE (address 40 00 00H).
RPN #1 allows tuning to be specified in steps of approximately 0.012 cents (to be precise, 100/8192 cent), and System Exclusive MASTER TUNE allows tuning in steps of 0.1 cent. One cent is 1/100th of a semitone.
The values of RPN #1 (Master Fine Tuning) and System Exclusive MASTER TUNE are added together to determine the actual pitch sounded by each Part.
Frequently used tuning values are given in the following table for your reference. Values are in hexadecimal (decimal in parentheses).
+ | + | + |
| + |
|
| + | ||||||
Hz at A4 | cent | RPN #1 | Sys.Ex. 40 00 00 | ||||||||||
+ | + | + |
| + |
|
| + | ||||||
445.0 | +19.56 | 4C | 43 | (+1603) | 00 04 | 0C | 04 | (+196) | |||||
444.0 | +15.67 | 4A | 03 | (+1283) | 00 04 | 09 | 0D | (+157) | |||||
443.0 | +11.76 | 47 | 44 | (+ | 964) | 00 04 | 07 | 06 | (+118) | ||||
442.0 | + 7.85 | 45 | 03 | (+ | 643) | 00 04 | 04 | 0F | (+ 79) | ||||
441.0 | + 3.93 | 42 | 42 | (+ | 322) | 00 04 | 02 | 07 | (+ 39) | ||||
440.0 | 0 | 40 | 00 | ( | 0 ) | 00 04 | 00 | 00 | ( | 0) | |||
439.0 | - 3.94 | 3D | 3D | (- 323) | 00 03 | 0D | 09 | (- 39) | |||||
438.0 | - 7.89 | 3A | 7A | (- 646) | 00 03 | 0B | 01 | (- 79) | |||||
+ | + | + |
| + |
|
| + | ||||||
<Example> Set the tuning of MIDI channel 3 to A4 = 442.0 Hz
Send RPN#1 to MIDI channel 3. From the above table, the value is 45 03H.
B2 | 64 00 | MIDI ch.3, lower byte of RPN parameter number | : 00H |
(B2) | 65 01 | (MIDI ch.3) upper byte of RPN parameter number | : 01H |
(B2) | 06 45 | (MIDI ch.3) upper byte of parameter value | : 45H |
(B2) | 26 03 | (MIDI ch.3) lower byte of parameter value | : 03H |
(B2) | 64 7F | (MIDI ch.3) lower byte of RPN parameter number | : 7FH |
(B2) | 65 7F | (MIDI ch.3) upper byte of RPN parameter number | : 7FH |
●The Scale Tune Feature (address: 40 1x 40)
The scale Tune feature allows you to finely adjust the individual pitch of the notes from C through B. Though the settings are made while working with one octave, the fine adjustments will affect all octaves. By making the appropriate Scale Tune set- tings, you can obtain a complete variety of tuning methods other than equal tem- perament. As examples, three possible types of scale setting are explained below.
❍Equal Temperament
This method of tuning divides the octave into 12 equal parts. It is currently the most widely used form of tuning,
especially in occidental music. On this unit, the default settings for the Scale Tune feature produce equal temperament.
❍Just Temperament (Keytone C)
The three main chords resound much more beautifully than with equal tempera- ment, but this benefit can only be obtained in one key. If transposed, the chords tend to become ambiguous. The example given involves settings for a key in which C is the keynote.
❍Arabian Scale
By altering the setting for Scale Tune, you can obtain a variety of other tunings suited for ethnic music. For example, the settings introduced below will set the unit to use the Arabian Scale.
Example Settings |
|
| |
Note name | Equal Temperament | Just Temperament (Keytone C) | Arabian Scale |
C | 0 | 0 | |
C# | 0 | +45 | |
D | 0 | +4 | |
D# | 0 | +16 | |
E | 0 | ||
F | 0 | ||
F# | 0 | +43 | |
G | 0 | +2 | |
G# | 0 | +14 | +47 |
A | 0 | 0 | |
A# | 0 | +14 | |
B | 0 | ||
The values in the table are given in cents. Refer to the explanation of Scale Tuning on page 198 to convert these values to hexadecimal, and transmit them as exclusive data.
For example, to set the tune
F0 41 10 42 12 40 11 40 3A 6D 3E 34 0D 38 6B 3C 6F 40 36 0F 76 F7
208 | Chapter 8. Appendix |