Overview; Autoconfiguration; Types Of System Exclusive Messages - Lexicon PCM 90 - MIDI IMPLEMENTATION DETAILS Midi Implementation Manual

Lexicon
An ASCII text version of this document is available on CompuServe under section seven of the MIDI
B forum. To access these documents:
• Enter CompuServe, type GO MIDIBVEN
• Select "section seven: Lexicon"
• Enter the Lexicon library

Overview

The Lexicon PCM 90 is a complex device with an involved System Exclusive implementation. This
document assumes familiarity with the functions and operations of the PCM 90.

Autoconfiguration

To aid development of editors and librarians which will remain useful throughout the lifetime of the PCM
90, regardless of the addition of new algorithms, we have provided a number of new System Exclusive
messages that allow a librarian to autoconfigure when it encounters new algorithms. Messages which are
particularly useful in autoconfiguration are:
System Configuration Response
Parameter Specific Response
Parameter Display Response
Effect Information Response
Patch Display Response
Matrix Mapping Response
Soft Row Display Response
Data Request

Types of System Exclusive Messages

There are several types of System Exclusive messages: Data Requests, Responses and Data Dumps.
Data Requests A request is initiated by a remote host (never by a PCM 90). A request usually results
in a dump. A request for data causes no change in the state of the PCM 90.
Messages A message is sent by a remote device to a PCM 90. It is a command for which there
is no response, such as a knob message. It may cause a change in the state of the
PCM 90.
Responses A response is a data packet that is sent from the PCM 90 to the another device, always
as the result of a request by that device. A response is never sent to the PCM 90. (It
may be harmlessly transmitted to a PCM 90, but results in no change in the PCM 90.)
Data Dumps A dump contains information about some aspect of the PCM 90's internal state. A
dump is transmitted by a PCM 90, either on request to another device, or to another
PCM 90 (via front panel dump commands SysEx Automation). When a dump is
transmitted to a PCM 90, it will normally cause a change in the internal state of the PCM
90. A dump may be purely informational, containing version information, etc. This sort
of dump may be received by a PCM 90 but results in no change. It is initiated only as
the result of an external request and may be considered as uni-directional.
PCM 90
MIDI Implementation Details
PCM 90 MIDI Implementation Details
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