Chapter 5 Appendices

Roland Exclusive Messages

1. Data Format for Exclusive Messages

Roland’s MIDI implementation uses the following data format for all Exclusive messages (type IV):

Byte

Description

 

 

F0H

Exclusive Status

41H

Manufacturer ID (Roland)

DEV

Device ID

MDL

Model ID

CMD

Command ID

[BODY]

Main data

F7H

End of exclusive

 

 

•MIDI status: F0H, F7H

An Exclusive message must be flanked by a pair of status codes, starting with a Manufacturer ID immediately after F0H (MIDI version 1.0).

•Manufacturer ID: 41H

The Manufacturer ID identifies the manufacturer of a MIDI instrument that sends an Exclusive message. Value 41H represents Roland’s Manufacturer ID.

•Device ID: DEV

The Device ID contains a unique value that identifies individual devices in the implementation of several MIDI instruments. It is usually set to 00H–0FH, a value smaller by one than that of a basic channel, but value 00H–1FH may be used for a device with several basic channels.

•Model ID: MDL

The Model ID contains a value that identifies one model from another. Different models, however, may share an identical Model ID if they handle similar data.

The Model ID format may contain 00H in one or more places to provide an extended data field. The following are examples of valid Model IDs, each representing a unique model:

01H

02H

03H 00H, 01H 00H, 02H

00H, 00H, 01H

•Command ID: CMD

The Command ID indicates the function of an Exclusive message. The Command ID format may contain 00H in one or more places to provide an extended data field. The following are examples of valid Command IDs, each representing a unique function:

01H

02H

03H 00H, 01H 00H, 02H

00H, 00H, 01H

•Main data: BODY

This field contains a message to be exchanged across an interface. The exact data size and content will vary with the Model ID and Command ID.

2. Address-mapped Data Transfer

Address mapping is a technique for transferring messages conforming to the data format given in Section 1. It assigns a series of memory-resident records—waveform and tone data, switch status, and parameters, for example, to specific locations in a machine-dependent address space, thereby allowing access to data residing at the address a message specifies.

Address-mapped data transfer is therefore independent of models and data categories. This technique allows use of two different transfer procedures: one-way transfer and handshake transfer.

•One-way transfer procedure (See Section 3 for details.)

This procedure is suited to the transfer of a small amount of data. It sends out an Exclusive message completely independent of the receiving device's status.

Connection Diagram

Device A

1

Device B

MIDI OUT

2

MIDI IN

MIDI IN

MIDI OUT

 

Connection at point 2 is essential for “Request data” procedures. (See Section 3.)

•Handshake-transfer procedure (This device does not use this procedure)

This procedure initiates a predetermined transfer sequence (handshaking) across the interface before data transfer takes place. Handshaking ensures that reliability and transfer speed are high enough to handle a large amount of data.

Connection Diagram

Device A

1

Device B

MIDI OUT

2

MIDI IN

MIDI IN

MIDI OUT

 

Connection at points 1 and 2 is essential.

Notes on the above procedures

*There are separate Command IDs for different transfer procedures.

*Devices A and B cannot exchange data unless they use the same transfer procedure, share identical Device ID and Model ID, and are ready for communication.

3. One-way Transfer Procedure

This procedure sends out data until it has all been sent and is used when the messages are so short that answerbacks need not be checked.

For longer messages, however, the receiving device must acquire each message in time with the transfer sequence, which inserts 20 milliseconds intervals.

Types of Messages

Message

Command ID

 

 

Request data 1

RQ1 (11H)

Data set 1

DT1 (12H)

 

 

•Request data #1: RQ1 (11H)

(This device does not use this procedure)

This message is sent out when there is a need to acquire data from a device at the other end of the interface. It contains data for the address and size that specify designation and length, respectively, of data required.

On receiving an RQ1 message, the remote device checks its memory for the data address and size that satisfy the request.

If it finds them and is ready for communication, the device will transmit a “Data set 1 (DT1)” message, which contains the requested data. Otherwise, the device won't send out anything.

Byte

Description

F0H

Exclusive Status

41H

Manufacturer ID (Roland)

DEV

Device ID

MDL

Model ID

 

11H

Command ID

aaH

Address MSB

 

 

 

 

LSB

ssH

Size

MSB

 

 

 

 

LSB

sum

Check sum

F7H

End of exclusive

 

 

 

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Roland GI-20 owner manual Roland Exclusive Messages, Data Format for Exclusive Messages, Address-mapped Data Transfer

GI-20 specifications

The Roland GI-20 is a groundbreaking MIDI guitar converter that allows electric guitarists to explore the vast world of MIDI technology. Designed to bridge the gap between traditional guitar playing and digital music production, the GI-20 transforms standard guitar signals into MIDI data, giving players access to a wide array of synthesized sounds and virtual instruments.

One of the main features of the GI-20 is its ability to track the guitar’s pitch with high accuracy. Utilizing Roland’s advanced technology, the device boasts rapid response times and minimal latency, ensuring that every note plucked or strummed is translated into MIDI in real-time. This precision is crucial for guitarists who wish to maintain their playing style while experimenting with synthesizers and sampled instruments.

In terms of connectivity, the Roland GI-20 is equipped with a 13-pin connector, allowing it to interface seamlessly with compatible Roland synths, sound modules, and other MIDI devices. Additionally, standard MIDI outputs enable connection to MIDI controllers and computers, providing an expansive toolkit for music creation.

The user interface is designed with simplicity in mind. A large LCD display allows for easy navigation of settings, while intuitive controls help players adjust parameters on the fly. Guitarists can also customize their performance by altering the sensitivity levels, enabling them to fine-tune how the device responds to their playing style.

The GI-20 offers an array of built-in sounds that mirror the capabilities of traditional synthesizers. These sounds can be layered or split into different tones based on the player’s preferences, offering a variety of sonic textures to enhance compositions. Furthermore, the ability to save and recall user settings allows for quick access to preferred configurations during live performances.

Another significant characteristic of the GI-20 is its compatibility with a wide range of guitars, including both electric and bass guitars. As long as the instrument is equipped with the appropriate pickup system, the GI-20 can effectively convert its output into MIDI signals.

In summary, the Roland GI-20 is a versatile and innovative tool for guitarists seeking to expand their creative horizons. With its accurate tracking, extensive connectivity, user-friendly interface, and a wealth of sounds, it unlocks the potential for guitarists to dive into the realms of electronic music and MIDI composition. Whether in the studio or on stage, the GI-20 opens up a world of possibilities for musicians looking to blend traditional guitar playing with modern technology.