Bernie Dawson
Although this utility is written for the Korg M3R it can be
easily adapted for other synthesisers.
When I grew tired of the Music 5000 sounds I expanded via
the Music 2000 route and got into MIDI. I bought the M3R expander unit. This is
a rack-mount 16-voice polyphonic multitimbral synthesiser. On this synthesiser,
instruments are arranged as 'programs', and these are combined into a
'combination'. Roughly speaking this equates to instruments and a mix on the Music
5000. While the factory sounds are very good, it wasn't long before I wanted to
alter them.
Unfortunately, like most digital synthesisers, access to
programming the sounds is via a few buttons next to a tiny 16 x 2 display. On a
rackmount unit this is on a vertical face, the wrong angle for your fingers.
When you consider that there are something like 60 different parameters that
can be altered for just one sound, it can involve a lot of button pushing!
Pining for the instrument panel approach of Notepad I
therefore decided to have a go at writing a remote editor. This involved understanding
a little about the nature of MIDI messages, which are of two types. Channel
messages convey note information (which note, note on, note off, velocity,
etc). System exclusive (sysex) messages can do much more, including changing
the sound parameters. The Music 2000 manual was particularly helpful and a few frustrating
nights in the back of the M3R manual eventually brought forth success. The
following is an example of a sysex message:
&F0 begin sysex message
&42 KORG ID
&3n n + 1 = MIDICHANNEL number
&24 M3R ID
35 Parameter number for filter cutoff
29 new value to be used
&F7 end sysex message
&42 KORG ID
&3n n + 1 = MIDICHANNEL number
&24 M3R ID
35 Parameter number for filter cutoff
29 new value to be used
&F7 end sysex message
Thus in the above example the instrument being edited in the
M3R would have its filter cut-off value altered to 29. On any other synthesiser
it is a matter of substituting the middle bytes, which will involve you delving
into the back of your own synthesiser's manual! Each byte is sent out using
MIDIOUT. Data values have to be processed to a 7 bit format since the MIDI
specification lays down that data bytes have bit 7 = 0. This is done within the
program by the word '7bit' which I got from the Music 2000 manual. The rest you
can suss out by analysing the program words.
It is no good doing this unless your synthesiser is set up
to receive the messages. In particular you need to ensure that the synthesiser
receives on the same channel as you are sending, that program changes are not disabled
and that sysex messages are enabled! Check out the 'info' within the program.
Program editing
To start the editor, LOAD it in, get 'panel' into Notepad
and follow the instructions. You will see the block cursor blinking on
'progch'. Hold down shift and alternative instrument pages are presented. This
works because each instrument page starts with a null word I've defined,
'INSPAGE'. This is one of Hybrid's rules and is how the program knows which
alternatives exist. To go into an instrument page, press the space bar. This is
exactly equivalent to choosing a Music 5000 instrument and then accessing the instrument
panel.
I never realised the panel form of Notepad was so flexible
until I wrote this utility. I can now change sounds on my M3R in an analogous
manner to changing Music 5000 sounds. The Return key, or the Music 4000
keyboard allows me to hear the results of the alterations.
The one disadvantage of my utility is that the communication
is one-way, BBC to M3R, so I have copied one program's parameters (Analog 2) as
the starting-off point for sound alteration. This cannot be solved without
knowing how to use the MIDI IN of the Music 2000 interface, for which the
manual gives no information.
Combination editing
This (U.M3Rexec) is a short file which should be EXECed in
to a music file. It proved a simple matter to adapt the program editing
approach to write a combination editor. I have stopped at an elementary Mixing
Desk approach. Start up a piece and enter 1 SHARE, then call up 'mdesk' in
Notepad. Again, press f2 to go into panel mode and you can then alter the
choice of programs or their relative volumes. This is analogous to the Mixing
Desk of the Music 5000 and again means that alterations can be done remotely,
from the BBC, without loads of button pushing.
Related files on this disc:
Published in AMPLINEX 028, September 1992
