Here is some information on SysEx Bulk dumps. This text happens to be discussing a Yamaha PSR, but all Yamaha bulk dumps work the same way.
(We volunteer in the MIDI Association, but actually work for Yamaha so this information is accurate).
By the way we attached the MFC10 manual and SysEx Bulk Dump information starts on page 33. .
Format of the system exclusive messages
The general format for the bulk dump system exclusive messages is:
F0 43 73 57 06 TT SS SS SS ZZ ZZ ZZ ... KK F7
TT, Type of data
09 = One Touch Setting
0A = Song
0C = Chord
SS SS SS, Size
Indicates the number of encoded data bytes in this system exclusive message.
Because the most significant bit of each byte must be zero, each byte only stores 7 bits of the value. The most significant bits of the value are in the first byte. For example, the bytes 02 11 7F indicate the value $88FF.
ZZ ZZ ZZ, Running total or End of section flag
If these bytes are 7F 7F 7F, this indicates the end of this type of data.
Otherwise, these bytes indicate the total number of encoded data bytes in all previous system exclusive messages for this type of data. (The value is stored using the 7-bit method mentioned above.)
If this is the end of this section, then there are three data bytes which indicate the total number of encoded data bytes for this type of data. (The value is stored using the 7-bit method mentioned above.)
Otherwise, these bytes encode the bulk dump data. Each pair of data bytes in the system exclusive message encodes one byte of the bulk dump data. The first byte of a pair stores the least significant nybble, the second byte stores the most significant nybble. For example, the bytes 0F 07 indicate the decoded byte 7F.
The sum of all bytes from SS SS SS to KK, inclusive, should equal 0, modulo 128 decimal.
THE MIDI ASSOCIATION (TMA)
The community of people who work, play and create with MIDI