[linux-audio-user] sysex questions

[Christoph Eckert]

Hi,


> I just bought a Boss GT-8 guitar effects processor and I
> know it supports downloading patches to your computer. I
> understand this works over midi by doing a sysex dump. What
> I don't understand is: How does the program I use "know"
> what kind of data I download? A patch? The system
> configuration? Everything? I know it does not need to be
> able to interpret the contents of those things but I'm not
> quite sure how this stuff works at all.

a) Start the dump on the device. Most synthesizers allow to 
choose which data to be sent: a single patch, a whole bank, 
the system configuration or its whole memory contents

b) send a sysex request to the device specifying which data 
you want to retrieve. The device should immediately send the 
desired data. See the manual of your device for details. The 
commands should be there.

> And the other way round: Could I do any harm to my GT-8 (or
> another midi device) by uploading wrong data to it? Or will
> it just give me an error message and reject the upload?

MOst devices use a (simple) checksum to verify the incoming 
data, but not all do so. Theoretically, it is possible to set 
the device in an undefined state. Some devices even allow to 
upgrade the OS in it using sysex...

> What programs can I use under linux? I know sysexxer, but I
> would rather like to use a command line tool.

Try amidi -l to get a list of all MIDI ports available on your 
computer.

BTW: Do you dislike Sysexxer or GUI programs in general? In 
the first case, I'd like to ask for feedback what we did 
wrong ;-) .

> As I said, silly questions

No, but a bit OT. But that's OK for me. If someone does not 
like this thread here, let me know and we'll discuss it per 
personal mail.


 Best regards


    ce