User manual LEXICON MPX G2

[. . . ] 1 Message Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 System Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Parameter Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] A table of Parameter Type numbers with a table of pointers to the data structures is used to get information about any parameter whose Parameter Type number is known. Parameter Type numbers #define NOTE_PARAM 0x002C #define MIX_PARAM 0x002D #define LEVEL_PARAM 0x002E table of pointers to structures &Note_param, &Mix_param, &Level_param, For each algorithm in the system (a total of 61), there is a table containing the Parameter Types used by the algorithm. For example: Detune (M) Parameter Types 0x002D - Mix 0x002E - Level 0x003B - Tune 0x003D - P Dly To edit a parameter, a pointer is initialized to the beginning of the 32-byte effect data block. This 32-byte data block is treated as an array of bytes. In order to access the target parameter the offset into this 32byte array must be calculated. This is done by determining the number of bytes used by each of the parameters preceding the parameter you want to edit. This is accomplished by walking through each of the parameter types, in the algorithm's Parameter Type table and using the Parameter Type number to access the parameter data structure to determine the number of bytes used. The pointer to the 32-byte effect data block is then incremented by the number of bytes used by this parameter. When the process is complete the pointer is left pointing at the target parameter's data. For example, in the "Detune (M)" effect, "Tune" is the third parameter. After a pointer is initialized to the beginning of the pitch "32 byte parameter data" array, it must be incremented past the first and second parameters' data to get to the "Tune" data. pitch parameter data: 0x64 - Mix 0x00 - Level 0x0A - Tune 0x01 - Tune Option 0x00 - P Dly 0x00 - unused 26 Lexicon MPX G2 MIDI Implementation Details The routine sets up a second pointer to the array of Parameter Type for the Detune (M) algorithm and accesses the structure for the first parameter, Mix. Detune (M) Parameter Types 0x002D - Mix 0x002E - Level 0x003B - Tune 0x003D - P Dly The Mix structure shows that it is a one byte parameter so the data pointer is incremented once. pitch parameter data: 0x64 - Mix 0x00 - Level 0x0A - Tune 0x01 - Tune Option 0x00 - P Dly 0x00 - unused The Parameter Type pointer is incremented to get the Parameter Type of the second parameter. Detune (M) Parameters Types 0x002D - Mix 0x002E - Level 0x003B - Tune 0x003D - P Dly The second parameter's structure is accessed and reveals that it is the one byte parameter "Level". The data pointer is incremented again and now points to the "Tune" parameter data. pitch parameter data: 0x64 - Mix 0x00 - Level 0x0A - Tune 0x01 - Tune Option 0x00 - P Dly 0x00 - unused Detune (M) Parameters "Types" 0x002D - Mix 0x002E - Level 0x003B - Tune 0x003D - P Dly As the operating system for the MPX G2 displays a maximum of two parameters at once, two such pointers are set up. There are two ways an off-line system can build a Parameter Types list for a given effect's algorithm. The parameters for all of these items are always the same. Otherwise, these parameters are accessed exactly as the effect parameters, including options. Sort Flags (Bytes 394-399, Parameter Type: 0x0115) Sort Flags consist of "effect types" (2 bytes) and "input types" (1 byte) (in that order). These define which to which sorting groups (database) the program will be assigned. The bit assignments for Effect types are: PITCH CHORUS EQ MOD DELAY AMBIENT CHAMBER GATE HALL INVERSE PLATE DUAL 28 0x0001 0x0002 0x0004 0x0008 0x0010 0x0020 0x0040 0x0080 0x0100 0x0200 0x0400 0x0800 Lexicon MPX G2 MIDI Implementation Details The bit assignments for Input types are: LIVE_PA VOCAL GUITAR KEYBOARD ACOUSTIC DRUMS TEMPO SOUND_FX 0x01 0x02 0x04 0x08 0x10 0x20 0x40 0x80 Audio Routing (Bytes 400-479) Audio Routing data defines how the audio data moves in and around the system for the current program. The audio routing is broken up into 8 blocks; one for each effect type, one for the input and one for the output. The effects blocks represent the signal flow into, through and out of the box (left to right on the Map and Order screens of the system). Each block consists of the following 5 one byte fields: 0 - Effect Type (Parameter Type 0x0146) 1 - Upper Input Connection (Parameter Type 0x0143) 2 - Lower Input Connection (Parameter Type 0x0144) 3 - Routing (Parameter Type 0x0145) 4 - Path Type These descriptions can be used for range limits, etc. . The Effect Type will always be one of the following: 0 - Pitch 1 - Chorus 2 - EQ 3 - Modulator 4 - Reverb 5 - Delay 6 - Input 7 - Output As the blocks represent signal flow through the box, the Effect Type of the first block will always be "Input" and the Effect Type"of the last block will always be "Output". Aside from that, the effects can be in any order with the condition that all of the effects types must always be used, and no single effect type can be used twice. Upper Input Connection and Lower Input Connection describe the way that the audio signal is fed to the respective inputs to the effect block. The following connection types are available: 0 - Stereo to Stereo 1 - Left to Left 2 - Right to Right 3 - Left to Left and Right (mono) 4 - Right to Left and Right (mono) If the block does not use the lower path, the input connection will be ignored but will become active if needed. Note that the input block "Upper" and "Lower" connections are place markers and are not actually used by the system. [. . . ] Optionally add "M" or "Meters". Treb Disp Units Use "reverb_freq_strings" Bassrt Disp Units Display `X' followed by "bass_rt_strings" 55 0x29 0x2a 0x2b 0x2c 0x2d 0x2e 0x2f 0x30 0x31 0x32 0x33 0x34 0x35 0x36 0x37 MPX G2 MIDI Implementation Details 0x38 0x39 0x3a 0x3b 0x3c 0x3d 0x3e 0x3f Crossover Disp Units Midrt Disp Units Lexicon 0x40 0x41 0x42 0x43 0x44 0x45 0x46 0x47 0x48 0x49 0x4a 0x4b 0x80 0x81 0x82 0x83 0x84 0x85 0x86 0x87 0x88 0x89 Use "reverb_freq_strings" offsetting the parameter value by 12. If reverb algorithm is 1 or 5 use the "chamber_decay_strings", if 2 then use "hall_decay_strings", if 3 use "plate_decay_strings" Percent50 Disp Units Multiply value by 2 and display in decimal followed by `%'. Msec Disp Units Display in decimal (optionally follow with "ms") Spread Disp Units Display in decimal. [. . . ]