Rodgers 535 - Page 43

Rodgers organs use a subset of the Roland standard MIDI System Exclusive format. All Rodgers
SysEx
packets use the Roland "Data Set" command, listed under "One Way Transfer Procedure"
in the Roland System Exclusive format specification. The first five bytes of this type of packet are
as follows:
~ Function
FOH Begin System Exclusive
41 H Roland/Rodgers SysEx ID
10H Device ID*
30H Model ID (30 = Generic organ data) ( 6D= 525/535 data)
12H Data
Set Command
*Note: This byte is usually 10H; however, the organ receives OOH - OFH and can be set to transmit
Device
10 OOH or transmit and receive any Device 10 between 10H and 1 FH. See the last page of
these notes for more information.
This header is then followed by the message body. The message body contains a subcommand
byte, an optional offset byte and a variable number of data bytes followed by a checksum byte
and a MIDI End Exclusive byte (F7). The checksum byte value is such that if all bytes beginning
with
the subcommand byte and ending with the checksum byte are added, the lower 7 bits of the
result will be all zeroes.
The following messages are used by Rodgers as of the introduction of models 525/535:
1. Stop Change
This message is transmitted each time one or more stops, couplers, or auxiliary controls
changes state. The state of each control is represented as a bit in one of the message data
bytes. The assignment of controls to specific bits is standardized for all Rodgers organs by
use
of the master code assignment list included herein. Activated controls (" on") are
represented by ones in the bit map. This message is transmitted on the Sequencer and
Pipe ports only on organs which have a separate MIDI Instrument port. It can,
however,
be received on the Instrument
port as well.
Subcommand byte: 01 H
Offset byte:
OOH - 22H This byte indicates the offset of the first data byte from the
beginning of the bit map. Normally, this will be zero, and the
entire map (35 bytes) will be transmitted. It is possible,
though, to send only part of the map beginning with the byte
indicated by this value.
Data Bytes: dd, dd, ...
The
data bytes represent the new state of the bit map
beginning at the offset specified above. Any number of data
bytes up to the full length of the bit map may be sent, although
the entire map is usually transmitted. Refer to the included
chart for stop map assignments.
39