Analogue-sequencer

So, Jim Combs and I are here on stage at Different Skies (well, I am  
- Jim's off giving a TV interview at the moment, but his P3 is here),  
and we've found a curious problem when syncing our two P3's. The  
stage setup has an Opcode Studio 5 dealing with beat clock for all 18  
musicians, and it's programmed up with a set of presets, each one of  
which designates a different MIDI input as beat clock source, sending  
it to all destinations. When either P3 is operating as clock source,  
pressing FUNC+RUN to reset clock on the next GBar causes the  
sequencer to stop at that point instead. If the P3 is not  
distributing clock, FUNC+RUN works fine. This appears to be a  
loopback issue: the same thing happens on a single P3 with a loopback  
MIDI connection.

We should be able to reprogram the Studio 5 to work round the problem  
temporarily (assuming I can find the various OMS and serial port  
drivers), but does this classify as a bug?

	-- N.


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

> and we've found a curious problem when syncing our two P3's. The  
> stage setup has an Opcode Studio 5 dealing with beat clock 
> for all 18  
> musicians, and it's programmed up with a set of presets, each one of  
> which designates a different MIDI input as beat clock source, 
> sending  
> it to all destinations. When either P3 is operating as clock source,  
> pressing FUNC+RUN to reset clock on the next GBar causes the  
> sequencer to stop at that point instead. If the P3 is not  
> distributing clock, FUNC+RUN works fine. This appears to be a  
> loopback issue: the same thing happens on a single P3 with a 
> loopback  
> MIDI connection.

As you'll know, FUNC+RUN sends a MIDI stop followed by a start on the next
gbar reset.
With a MIDI loop in place, P3 is responding to its own MIDI stop message.

It's not necessarily wrong - by responding to a MIDI stop while running
internally, you can stop and restart a master P3 from a connected device
that you want to become master without having to manually stop P3 (on remote
device, start-stop-start brings P3 into sync).
This does mean a P3 with a MIDI loop can be self-stopping, but MIDI loops
are generally not advisable.
It's a question of which scenario is more likely...

However, I have already changed this behaviour in the current beta I have
here, since I was going over the MIDI slave code to look for the source of a
problem someone else had with external sync.
I can mail you the updated build if you're feeling brave enough to do an
update just before a gig ;-)
I guess you have a few days before the big night, so you could always
downgrade if you find anything odd.

Best regards,
Colin Fraser
Sequentix Music Systems Ltd
http://www.sequentix.com

On 12 Sep 2006, at 11:47, Colin Fraser wrote:

> I can mail you the updated build if you're feeling brave enough to  
> do an
> update just before a gig ;-)
> I guess you have a few days before the big night, so you could always
> downgrade if you find anything odd.

True enough. As you point out, the P3 is not doing anything wrong, so  
we should really fix it at our end (in the Studio 5) - but if you  
have a clean mod. which solves our problem then we can give it a  
spin. (I assume the file on Yahoogroups is the current release; I  
don't have a local copy here.)

Actually, Jim's not back on stage yet, so if you mail it through  
quickly I can try it on his P3 first...!

	-- N.


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