sysex header


can anyone tell me what a sysex header is??

F0, I think.

That’s if you’re talking about a system exclusive event in MIDI.

If you’re talking about something else, I won’t continue. :)

But if you are, a sysex MIDI message is one that is not “note” related.

In other words, it could be a message that dumps all your synth settings into your PC for storage or whatever.

Sysex messages are not of a fixed length, unlike other MIDI events.

Anyway, all sysex events start with F0, and end with F7.

Usually, but not always, the second byte is either, 7E or 7F (one means realtime and the other means not real time, but don’t ask me which is which).

So, everything lying between F0 7E/7F and F7 is data, so I suppose the sysex header is F0 7E (or FO 7F).

Possibly. :)


SYSEX is System Exclusive MIDI Events. They are exclusive to the system - a particular manufacturers device.

There is two ways of doing SYSEX. One is a single sysex event. It’s about the same as a MIDI note, CC Event, or Patch Change. These are SYSEX realtime event for the most part.

The other is broken into multiple parts – header and data pretty much. The first part is usually what’s called the header. It is itself a single MIDI Event that tells the MIDI device that there’s more SYSEX data to follow—

SOX (Start Of eXclusive is always F0 HEX)
KID (the manufacturers exclusive ID)
DEVID (the the particular ID of the device)
PID (the particular Product)
MSGTYPE(what the following data is)
MESSAGE (variable length data)
EOX (End Of eXclusive, 70 HEX value)

That message data comes in an unbroken stream - raw data in a way – that is terminated by a single EOX (70 HEX value).


Doing it this way allows for an unlimited amount of data to be streamed to a MIDI device. It can be use for anything the MIDI device wants since other devices by definition of what SYSEX is throw away what it doesn’t understand (Not my device ID? – bye bye).

EDIT (replaced gobledygook link)


Well, that was a wee bit more detailed answer than mine, thank you Phoo. :D

But, are you sure that the EOX byte is 70?

I’d have bet folding money it was F7, (but there again, I have to take my shoes and socks off to count in hex so I’m probably wrong. :cool: ).


Yep…my typo. It’s F7h.

Dyslexia strikes again - I looked right at it and it said F7…though it looks surprisingly like 70 right now. :)