Bitpack Field Interdependencies - Lexicon PCM 80 - MIDI IMPLEMENTATION DETAILS Midi Implementation Manual

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If the Count of Patch Points is 0, the Patch Information Block will end with the above information. The Count
of Patch Points can be anywhere from 0-8. For values 1-8, the patch's information block will be filled out
with the following sequence repeated for as many points as are defined.
For the second field, the "n" bit count is anywhere from 1-16. It is the number of bits needed to represent
any value for that patchable parameter. For example, refer to the partial list of Patchable Parameter
Information in the previous section. If a patch destination parameter was Controls Mix, the number of bits
for the Destination Patchable Parameter Value would be 7, and the range of values for that parameter
would be 0-100. For every patch point there would be 7 bits to hold the Patch Point Value, and 7 bits to
hold the Destination Parameter Value. If the patch destination parameter was Control InLvl L, the number
of bits would be 8 and the range of values would be 0-160. For every patch point there would be 7 bits
to hold the Patch Point Value, and 8 bits to hold the Destination Parameter Value.

Bitpack Field Interdependencies

As mentioned in the previous section, there are details of implementation in the Patching Information that
are dependent (on an algorithm-by-algorithm basis) on the order of fields in the previous group, the
Patchable Parameter Information. The Plate Algorithm (Algorithm 0x00) will be used as an example to
point out these details.
There are 88 fields in the Patchable Parameter Information for the Plate Algorithm. Earlier information
might lead you to take the Edit Matrix for Plate from the User Guide, to count all the parameters from
Controls Mix up to (but not including) the Patch 0 information, to remove all the unpatchable parameters
from that list, count them all and see that there are 88 parameters. . . Not exactly so. . . You would find
there are 74 patchable parameters in the Plate Edit Matrix. The reason there are 88 fields in the Patchable
Parameter Information is that 14 of the 74 parameters in the Plate Edit Matrix are parameters which can
be represented in Tempo form in addition to some standard form (milliseconds, Hz, ...). Therefore, each
of those 14 parameters needs an additional 1-bit indicator flag as to whether the value for the parameter
is to be interpreted in its standard form or in tempo. 74 + 14 = 88.
Bits Contents
7 Patch Point Value (0 -27)
n Destination Patchable Parameter Value for that patch point
PCM 80 MIDI Implementation Details
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