Here is an update to the cassette data format:
byte 1: 0xB3 (I assume this is header info)
byte 2: 0xBF
byte 3: 0x00 (MIDI channel - 1)
bytes 4-259: Sequence data
bytes 260-270: Chord memory
bytes 271-290: ??? (so far always 0xFF)
bytes 291-1634: Patch data
byte 1635: ??? (different between the factory dump and my Poly 800)
byte 1636: Checksum (unsigned sum of bytes 3 through 1635)
The changes are identification of byte 3 as the MIDI channel, adding the chord memory region, and changing the checksum start from byte 4 to byte 3.
Note: The chord memory *should* only need 8 bytes to save an 8-note chord, but there are 11 bytes reserved. There may be some other information in that region that hasn't been identified yet.
byte 1: 0xB3 (I assume this is header info)
byte 2: 0xBF
byte 3: 0x00 (MIDI channel - 1)
bytes 4-259: Sequence data
bytes 260-270: Chord memory
bytes 271-290: ??? (so far always 0xFF)
bytes 291-1634: Patch data
byte 1635: ??? (different between the factory dump and my Poly 800)
byte 1636: Checksum (unsigned sum of bytes 3 through 1635)
The changes are identification of byte 3 as the MIDI channel, adding the chord memory region, and changing the checksum start from byte 4 to byte 3.
Note: The chord memory *should* only need 8 bytes to save an 8-note chord, but there are 11 bytes reserved. There may be some other information in that region that hasn't been identified yet.