I posted this on the usb list but there was no response. My Machine is a Mac Pro 4,1 desktop currently running OS X 10.10.5 Yosemite. (I have bootable partitions for Snow Leopard - through Mavericks). I have an Edirol (Roland) PCR-1 USB Audio Interface & MIDI Keyboard (25 keys). Roland’s latest driver for this device is Sep 2009. The device works on OS X 10.6.8 Snow Leopard through 10.9.5 Mavericks (Roland has released a later driver but it did not include this device. The PCR-1 is attached to the General Purpose USB Hub (front of the Mac Pro). In Yosemite 10.10.5 the information in System Report for each of the 2 ports on the device is identical on Snow Leopard through Mavericks including for Current Required (mA) 100 and also in Yosemite EXCEPT for Current Required (mA) where it shows Unknown (The device has not been configured). So the PCR-1 cannot be made available as an online device. This is the first time I’ve ever looked into USB drivers. Clearly something changed between Mavericks and Yosemite in the IOKit configuration process. ( I did look at the <https://developer.apple.com/library/mac/documentation/General/Reference/APIDiffsMacOSX10_10SeedDiff/frameworks/IOKit.html> but it’s no help). Is there a replacement for USBProber? or do we have to go by this: <http://lists.apple.com/archives/usb/2015/Jan/msg00004.html> I would really appreciate help in trying to understand what changed and how to proceed. So please point me at relevant docs, debug SW etc. (I use Xcode 6.4) TIA Peter _______________________________________________ Do not post admin requests to the list. They will be ignored. Usb mailing list (Usb@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/usb/pteeson%40icloud.com This email sent to pteeson@icloud.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app... This email sent to site_archiver@lists.apple.com