Five12 Numerology

[ibi sum]

On Sat, 2011-01-01 at 11:35 -0600, James R. Coplin wrote:
> It's a G4 tower.  The interface that is giving me trouble on the Mac does
> work fine on the PC.  

On OSX, MIDI drivers are a damned nuisance these days, especially for
the older PPC architecture.  Many of the older MIDI interfaces for
PPC(G4) required a binary loader that would send the device its firmware
whenever you first plug it in - if this doesn't happen, often the device
will get into a very peculiar state.  I would try using the kextload
cmd-line tool (and its pal, kextunload) to force the driver to reload
from scratch next time you get this issue .. it may provide a clue and a
possible solution to your problem.

The way it works - the device initially enumerates as a non-powered
(low-speed) USB device, the Mac USB port acts accordingly and switches
into Low-Speed mode, the binary uploader sends the device a new
firmware, the device resets and expects a new USB enumeration
transaction which, for whatever reason (very poorly written driver)
doesn't happen, and you end up completely out of sync.


Also, USB ports can enter dodgy states the more you plug stuff in/unplug
it.  Is the MIDI interface going through a properly powered USB hub, or
is it directly connected to the Mac?  Because, frankly, the USB port
itself may be acting up, thinking you've plugged in a device that is
self-powered rather than bus-powered (see above firmware loader problem)
when it really isn't, and so on.  There are definitely things you can
investigate here, I suggest getting USB Prober involved in your debug
sessions, and see if you can find out whats up.

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ibi sum
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