sorry I read your message again and found the answer to the latest question, so I have a new one, if you don't mind:
in kmidimon did you see ALL of your bytes coming through or only some of them?
My point is: I believe that if you send bytes over an old-style MIDI connector, it should not matter how spaced in time they are: the receiver should be able to reconstruct the message. I expect that the same should happen for software connections. So, if bytes are dropped because of improper use of the API, then I understand the issue.
But I would struggle to understand why it should fail if all the bytes are actually delivered.
I must say that a long time ago I was successfully controlling a Roland Sound Canvas over sysex generated in Pd-Extended 0.43.
Best,
Giulio
From: Albert Graef <aggraef@gmail.com>
To: Giulio Moro <giuliomoro@yahoo.it>
Cc: Ticket 1272 <1272@bugs.pure-data.p.re.sf.net>; "pd-dev@lists.iem.at" <pd-dev@lists.iem.at>
Sent: Sunday, 16 October 2016, 19:08
Subject: Re: [PD-dev] [pure-data:bugs] #1272 midiout not working correctly on ALSA
Hi Giulio,
no, AFAICT that's not the way ALSA works. I haven't really looked in the ALSA code, but it seems that assembling the MIDI messages has to be done using the corresponding sequencer API calls. There might be some drivers which handle this, but I never had this working properly when outputting sysex using either internal ALSA connections or external MIDI gear via a USB-MIDI device.
All I can say is that the suggested patch seems to be the right way to do this (those API calls are there for a reason), and that it works for me with every MIDI equipment I tried it with.
Albert