I couldn’t see where else to place this! I’m curious to know if anybody else has spotted any problems with Windows 7 and MIDI, and specifically the reception of MIDI Clock causing Windows 7 to have problems when also receiving SYSEX dumps.
I think it’s also worth people being aware of this issue! Even if I can’t find fellow sufferers!
I have a strange problem when trying to receive SYSEX bulk dumps from my Yamaha EX5 synth (an awesome beast and one of Yamaha’s finest!).
I create my own Java librarians for different synths (over at www.xfactory-librarians.co.uk), and one of my users spotted this problem. When trying to import SYSEX data from the EX5 using “ex.factory” he was getting Time-out errors. It all works fine on XP. I missed the problem first on Windows 7 because the EX5 has two sets of MIDI Ports and for reasons to do with my live setup and how I have MIDI A configured I use the MIDI B port to output data. SYSEX Data transmitted on this port is not lost. My user was using MIDI A to transmit the SYSEX data from the EX5 to the PC and he was not receiving data.
I have verified that this is not a problem with my librarian or Java MIDI, because I get exactly the same problem if I use the wonderful MIDI-OX to manually request a SYSEX dump; it also times out (and works on XP!).
The behaviour is the same using different PC MIDI interfaces as well, so that rules out hardware and a vendor driver issue.
Anyway, I started looking for differences between my EX5 MIDI A and MIDI B outputs, and I never realised that its MIDI A Output by default sends out MIDI Clock Messages in addition to running status. I saw this when using MIDI-OX’s low level input monitor.
So, if I set the EX5 to external sync so that it stops sending MIDI Clock, then Windows 7 quite happily imports SYSEX data from the EX5 MIDI A output with no time-outs, which verifies that it’s an issue with Windows 7 and MIDI Clock.
With MIDI Clock on the EX5 active again, I messed about with different MIDI buffer sizes in MIDI-OX and with very small buffers, I managed to get partial reception of SYSEX messages which were the length of a single buffer, but never a full message.
I’ve trying googling for the issue but haven’t found anything of relevance.
So has anybody else seen this?