The Yamaha AN1x Synthesizer mailing list

--- In AN1x-list@yahoogroups.com, "derek192603" <dacook.sa432bb@...> wrote:
>
> As you've found, they seem to work fine for basic MIDI duties but are hopeless at handling SYSEX data. Probably because they cannot handle the burst of data. 

That does indeed appear to be the case.  The vendor:product id of my device is 1a86:752d, which is a CH345 device made by QinHeng Electronics.  I've discovered this device is included in Linux reports of buggy USB MIDI firmware that "reports it can do more than 4 bytes in a packet when they can only properly handle 4".

http://comments.gmane.org/gmane.linux.alsa.devel/83706
and
https://bugtrack.alsa-project.org/alsa-bug/view.php?id=3752

This fits perfectly with the missing 5th and 6th data length bytes I've witnessed.

It looks from the above that the Linux guys are getting around the problem by ignoring the reported capability of such devices, and restricting the packet size to 4 bytes.  I did actually already try the device under Crunchbang with no success, maybe I need to try updating the ALSA driver.

But if it can be fixed in Linux, surely it can be fixed in Windows too - anyone know if there are any alternative drivers available?

[PS will my messages always have to be approved by a moderator on this group?]