markus@emqu.de

I want to create a sysex message from a Name to send over midi to an external receiver.

e.g. 
MAX/MASP
myname --> midiChannel -> midiOut

JAVA application
--> midiIn --> display:"myname"

encode-text-to-sysex-to-send-over-midi

You might want to work on the text formatting, but this solves the midi and sysex issue.

"Normally, midi transmits 7bits data. Although your technique works thru

an IAC bus, I'm not sure it will work with 8bits char with hardware

MIDI device (I cannot test myself now!). So the integer should be split

into 2 7 bits words (or whatever other technique).

Not sure that's true. The sysex header byte is 0xf0 (240 decimal), note on is 0x80, etc.. last time I checked, that's 8 full bits. Now, the data might be encoded as 7 bits, but for sysex, 8 bit data is OK.

"Normally, midi transmits 7bits data. Although your technique works thru
an IAC bus, I'm not sure it will work with 8bits char with hardware
MIDI device (I cannot test myself now!). So the integer should be split
into 2 7 bits words (or whatever other technique).
"

Not sure that's true. The sysex header byte is 0xf0 (240 decimal), note on is 0x80, etc.. last time I checked, that's 8 full bits. Now, the data might be encoded as 7 bits, but for sysex, 8 bit data is OK.


> "Normally, midi transmits 7bits data. Although your technique works thru

> an IAC bus, I'm not sure it will work with 8bits char with hardware

> MIDI device (I cannot test myself now!). So the integer should be split

> into 2 7 bits words (or whatever other technique)."

> Not sure that's true. The sysex header byte is 0xf0 (240 decimal), note on 

> last time I checked, that's 8 full bits. Now, the data might be encoded as 

You're forgetting that the MSB in each MIDI byte is reserved for designating 

> "Normally, midi transmits 7bits data. Although your technique works thru
> an IAC bus, I'm not sure it will work with 8bits char with hardware
> MIDI device (I cannot test myself now!). So the integer should be split
> into 2 7 bits words (or whatever other technique)."
>
> Not sure that's true. The sysex header byte is 0xf0 (240 decimal), note on 
> is 0x80, etc..
> last time I checked, that's 8 full bits. Now, the data might be encoded as 
> 7 bits, but for
> sysex, 8 bit data is OK.

You're forgetting that the MSB in each MIDI byte is reserved for designating 
whether it's a status or data byte.

On around Feb 28, 2006, at 15:25, Mark Hill said something like:

> Not sure that's true. The sysex header byte is 0xf0 (240 decimal), 

> note on is 0x80, etc.. last time I checked, that's 8 full bits. Now, 

> the data might be encoded as 7 bits, but for sysex, 8 bit data is OK.

Either way, the actual *content* of a MIDI byte is encoded in bits 0-6. 

Bit 7 (MSB) is the status bit. MIDI **data** are restricted to 7 bits 

That is the MIDI standard the way it's been forever.

If you want to send arbitrary streams of serial 8-bit bytes, you can 

do, but it ain't MIDI. If IAC let's you do this... you're maybe in 

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On around Feb 28, 2006, at 15:25, Mark Hill said something like:
> Not sure that's true. The sysex header byte is 0xf0 (240 decimal), 
> note on is 0x80, etc.. last time I checked, that's 8 full bits. Now, 
> the data might be encoded as 7 bits, but for sysex, 8 bit data is OK.

MIDI Status bytes have the MSB set
MIDI Data bytes have the MSB clear

Either way, the actual *content* of a MIDI byte is encoded in bits 0-6. 
Bit 7 (MSB) is the status bit. MIDI **data** are restricted to 7 bits 
per byte.

If you want to send arbitrary streams of serial 8-bit bytes, you can 
do, but it ain't MIDI. If IAC let's you do this... you're maybe in 
luck, but it's breaking the MIDI spec.

MIDI always transmit 8 bits bytes. The first bit indicates if this is 

a status byte (1) or a data byte (0). Status bytes indicate the start 

of a new midi message, or in the case of a SYSEX it could also 

indicate the end of a sysex message (0xFF or 247). If you send sysex 

messages where the data bytes between the first and last bytes are in 

the range 128-255 you might risk them being misinterpreted at the 

receiving for being something else, e.g. the start of a note-on 

message (144-159) or a pitch-bend message (224-239).

For this reason you should reformat your character values so that one 

char is sent as two bytes, to make sure that the first bit of each of 

the bytes is 0. Peter Elsea provides externals for dealing with 

You can do with standard Max obejcts as well. The patch below 

provides abstractions for converting ascii to and from nibble as well 

as messages to and from sysex. I did not bother to add Checksum at 

the end of the sysex messages, or an manufactorer ID to the sysex 

that could have been used to tell it apart from sysex messages meant 

MIDI always transmit 8 bits bytes. The first bit indicates if this is  
a status byte (1) or a data byte (0). Status bytes indicate the start  
of a new midi message, or in the case of a SYSEX it could also  
indicate the end of a sysex message (0xFF or 247). If you send sysex  
messages where the data bytes between the first and last bytes are in  
the range 128-255 you might risk them being misinterpreted at the  
receiving for being something else, e.g. the start of a note-on  
message (144-159) or a pitch-bend message (224-239).

For this reason you should reformat your character values so that one  
char is sent as two bytes, to make sure that the first bit of each of  
the bytes is 0. Peter Elsea provides externals for dealing with  
"nibbles" as part of Lobjects.

You can do with standard Max obejcts as well. The patch below  
provides abstractions for converting ascii to and from nibble as well  
as messages to and from sysex. I did not bother to add Checksum at  
the end of the sysex messages, or an manufactorer ID to the sysex  
that could have been used to tell it apart from sysex messages meant  
for other gear.

On 28 Feb 2006, at 14:25, Mark Hill wrote:

> Now, the data might be encoded as 7 bits, but for sysex, 8 bit data 

As other folks have suggested (or will suggest): MIDI data bytes are 

7-bit. Sysex messages start with 0xF0 and end with 0xF7, but all the 

intermediate bytes have to have the top bit clear. (We could argue 

about whether realtime messages with the top bit set are allowed 

within Sysex; I don't know of any kit, hardware or software, that 

Back in the days when hardware synthesisers roamed the land, 

manufacturers used to implement a scheme to "stream" 8-bit data into 

7-bit bytes. (Well, the Japanese did; the Americans often favoured 

Those with long memories might want to check the command options in 

the configuration files used by Max's "lib" object.

nick rothwell -- composition, systems, performance -- 

> Now, the data might be encoded as 7 bits, but for sysex, 8 bit data  
> is OK.

As other folks have suggested (or will suggest): MIDI data bytes are  
7-bit. Sysex messages start with 0xF0 and end with 0xF7, but all the  
intermediate bytes have to have the top bit clear. (We could argue  
about whether realtime messages with the top bit set are allowed  
within Sysex; I don't know of any kit, hardware or software, that  
does that.)

Back in the days when hardware synthesisers roamed the land,  
manufacturers used to implement a scheme to "stream" 8-bit data into  
7-bit bytes. (Well, the Japanese did; the Americans often favoured  
nybble-encodings.)

Those with long memories might want to check the command options in  
the configuration files used by Max's "lib" object.

   nick rothwell -- composition, systems, performance -- http:// 
www.cassiel.com


> On 28 Feb 2006, at 14:25, Mark Hill wrote:

> > Now, the data might be encoded as 7 bits, but for sysex, 8 bit data 

OK, sorry for my mistake with sysex. I was rembering something that I had in fact done with meta events.

You can send a text string over MIDI by starting a meta event (0xFF) of type 1 (0x01) then a string of ascii characters.

Max support for meta events isn't strong, but you can parse this data out of the output of [midiin] with a little programming. I have this somewhere... but it's a long time ago. I'll see if I can dig it out.

http://www.sonicspot.com/guide/midifiles.html

>
> On 28 Feb 2006, at 14:25, Mark Hill wrote:
>
> > Now, the data might be encoded as 7 bits, but for sysex, 8 bit data  
> > is OK.
>

OK, sorry for my mistake with sysex.  I was rembering something that I had in fact done with meta events.

Max support for meta events isn't strong, but you can parse this data out of the output of [midiin] with a little programming.  I have this somewhere... but it's a long time ago.  I'll see if I can dig it out.

see:
http://www.sonicspot.com/guide/midifiles.html


To send meta events, you may use Peter Swinnen's psw.midifile.parser 

To send meta events, you may use Peter Swinnen's psw.midifile.parser 
source to make it real-time, maybe...

Encode text to SYSEX to send over midi