Emu XL-7 & MP-7 User's Group

Thanks for the link (and for helping Bruno sort it out), and welcome!!! Its late at night here and the white on black is blinding me. I will take a look another time. Maybe I will have to just copy it to a text file to read it.

Steve

--- In xl7@yahoogroups.com, Przemysław Węgrzyn <pwegrzyn@...> wrote:
>
> Hi!
> 
> >  
> >
> >     I don't follow the explanation of blocks. For me, the next data
> >     value after the byte pair 00 7F is 01 00.
> >
> >
> > Indeed, but here we are talking about sending a stream of bytes (e.g.
> > MIDI file) through the File Dump - not pairs! Bytes themselves don't
> > have the 7F limitation - in fact, in the MIDI file you can find the
> > bytes with the highest bit set (Variable Length Values - check the
> > bottom of this page: http://www.ccarh.org/courses/253/handout/smf/).
> > Also, File Dump is not only used to send MIDI files, but also samples,
> > which are binary data not limited by MIDI standard in any way, thus
> > they can be full of FFs.
> >
> > So, to overcome the SysEx limitation, one have to get rid of the
> > highest bits - in case they were set. Bytes are grouped by seven, and
> > the highest bits of every byte are grouped to form the eight byte.
> > That way we can guarantee that no byte will ever be bigger than 7F.
> 
> Just in case you want to know more about it, here's a nice description:
> http://www.slaveksamal.com/files/midispec.htm#nusx_fd
> 
> This is exactly the format used by XL7 to dump the patterns (and not
> only that). The only tricky part is the "file" name sent in "File Dump
> Request" message (sent towards XL7), which appears to be the only
> EMu-specific part here.
> 
> (BTW, I'm the guy helping Bruno to figure all that out, just joined the
> XL7 list :)
> 
> --
> Przemek
>