Hello Geoff,
I have heard of Commander but it seems a bit mythological because it is nowhere to be found. I use a thing called Cyber2Editor. It is Japanese but can still be downloaded if you sort of squint at the Japanese text. Lol.

I am suspect of CHK simply because I can't find anything to sum that is correlated with its value!

The interpretation of the SYSEX was just, initially, to get the names of the PRESETS. However, if I am to build a foot controller and Cyber Twin end box to control the Cyber Twin, if thought it would be good to know what the amp settings were before I changed them.

However, they do not matter in the initial stages of my project, which I will describe in my next postings.

Regards
Josie

Project Definition #1
Why? Because I have neurological problems in my feet, i need a stage area free of cables. Also, the floorboard switch controller must have a small vertical height and must be laid out very simply. Standard floorboards just have too many switches in too many rows for me to able to use them without falling over!

So the system will consist of an Android eye level high visible screen connected by Bluetooth to a 9 switch, with a footpedal floorboard, with and a second Bluetooth unit at the Cyber Twin end to control the Cyber Twin and up to 2 modified guitar stomp boxes, in my case a BOSS compressor and an Ibanez TS9 Tube Screamer. The floorboard and the rig end box will be equipped with Arduino microboards and Bluetooth boards.

The floor board will look like this, with or without the detailed information contained in the 8 digit 7 segment display.

Project Definition #2
The Android tablet will communicate with floor board and attach a meaning to the switches. I will maintain a list of such meanings. I see these are being linked to whichever particular track is to be played.

The Android tablet will then issue commands to the rig end box depending on what switch is pressed and which set of switch settings are currently selected on the Arduino. So the Cyber Twin and the 2 stomp boxes will respond accordingly.

There is no reason that the Android could not also act as Cyber Twin preset editor and SYSEX DUMP file manager. However, that requires that I correctly understand the data of a single preset MIDI DUMP file. The notorious 55 bytes.

Nomally, the total 7-bit sum of the dump data, including the checksum byte, should add to 7-bit zero.

That's what the GS and XG standards use, but the MIDI Tuning standard uses XOR instead of addition.

Anyway, for both messages (in the screenshot and in the PDF), if I ignore the checksum byte completely, the other bytes add up to 0x7F.

And....

0x7F add 1 (chk) = 0 (7 bits)? Which is what it's supposed to be for a 'normal' checksum?

Why did you say 'ignore the checksum byte completely'?

Geoff

Why did you say 'ignore the checksum byte completely'?
I meant it in 2 ways
1. The checksum calculation in the right hand pane is just incorrect
2. Just assume all is OK and carry on with my interpration
However:
Many thanks Clemens and Geoff
Xor and not arithmetic summation was the key. I should have known better. I am shamed and humbled.
I have found that the checksum operation must be performed over ALL the inner 53 bytes of the 55 byte data "file". i.e. excluding 0xF0 at start and 0xF7 at the end.
This consistent with this pdf about instructions for the Fender G-DEC (see pages 22 et seq)

G-DEC MIDI Guide

In it the author says:
"Checksum byte - The checksum is the sum of all of the bytes from the Fender ID(08) to just before this byte which is then masked by 0x7F"
Not quite how I would have expressed and just a tiny bit wrong.

However, I am now clear tp proceed with the interpretation with the assurance of the checksum showing me that MIDI USB converter is OK. I have a box full of ones which aren't!

Thank you guys
Regards
Josie

So my interpretation, so far, of the SYSEX dump data:
00007D8C 1 -- F0 Buffer: 6 Bytes System Exclusive
SYSX: F0 08 21 11 02 F7
00007E76 1 -- F0 Buffer: 55 Bytes System Exclusive
SYSX: F0 08 21 11 02 00 01 2A 00 43 68 61 6D 70 20 27 00 34
SYSX: 39 20 20 20 20 20 05 20 20 24 0C 40 42 71 0B 40 7F 7C
SYSX: 48 28 73 68 00 00 00 7F 7F 7F 7F 00 00 00 00 00 00 01
SYSX: F7
00007EC4 1 -- F0 Buffer: 7 Bytes System Exclusive
SYSX: F0 08 21 11 02 7B F7

is:

File start: {F0 08 21 11 02 F7}
Data header: {F0 08(<- start of checksum) 21 11 02 00}
Data Checksum: OK
Data trailer: F7
File end: {F0 08 21 11 02 7B F7}
Interpretation
Display Name: A00 Champ '49
FirstBitPackWord: 240C: [0010010000001100]
bits unknown: {14, 15}
Tone Stack Type: Tweed
Tone Stack Position: Pre-Distortion
Drive Circuitry: Tweed Tube1
Reverb Type: Small Ambience
Timbre: None
Gain: 8.1
Volume: 5.4
Treble: 2.4
Middle: 9.6
Bass: 9.2
Presence: 1.0
Reverb: 1.0

regards
Josie

Hi Josie,

I'm trying to convert some parameters of a single preset to CC using StreamByter.
I only have a basic knowledge of this Midi Magic and I'm trying to identify the description and values for the dial readings in the "dump"

Your posts here have given me some hope and a starting point. Where did you end up with this?

Cheers,

Greg