On Sun, 4 Dec 2005 00:52:27 +0000, Dan Williams <williams.dan at gmail.com> wrote: A USB device is initially required to pull no more than one load (100 ma) from the power bus. On initialization, the USB host queries the device to obtain the number of loads it requires (up to 5 - 500 ma) and determines whether it can provide that amount of power to the device. For devices requiring more than one load, the device is not allowed to pull more than the initial load until configured by software. From the spec: "Hubs that obtain operating power externally (from the USB) must supply five unit loads to each port. Battery powered hubs may supply either one or five unit loads per port." So this should work independent of host initialization (if the hub follows the rules). If the device is a standard device as defined by the specs, the host should initialize power independent of a driver. However, if you are on a M$ box, they don't always follow the rules even though they are a signatory on the spec... CRC