Re: Powerbook5,7 (G4 17") and USB 2.0 disk drive
On Wed, May 23, 2007 at 04:08:23PM -0400, Andrew J. Barr wrote:
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> I have an external USB2 disk drive enclosure with a 40GB PATA IDE disk
> drive in it. It has an odd cable, with USB "A" connectors on both ends
> and two connectors on the "host" side. I don't know the reason for
> this, but in my Intel Desktop Board DG965RY (Core 2 Duo EM64T) and my
> Thinkpad R51 the drive works properly with one -or- two USB connectors
> plugged in. On the Powerbook, due to the layout of the USB connectors,
> connecting both plugs is not possible, and the drive does not work with
> just one. The LED lights up, but the disk just clicks helplessly. The
> kernel says "new high speed USB device using ehci_hcd" but that's it.
> It does not identify the device (not visible in lsusb) and it certainly
> does not allow me access to my data. I plugged this drive (using just
> one connector) into my partner's computer and it spun up and operated
> normally as near as I could tell from listening to it (his computer
> runs Windows and the disk is ext3-formatted). I assume this is a power
> issue, perhaps the Powerbook USB HCI is enforcing some limit that the
> other controllers do not? Is there any way to work around this in
> software, e.g. a kernel patch? Thanks in advance.
The USB specs mention 0.5 A at 5V, so around 2.5W. This is not enough to
drive a harddisk, especially a 3.5" one.
I know that some apple models did use higher than spec voltage on the
USB controler, and probably your intel board does this.
This is what makes the firewire solution so much superior to the usb
one, since it can usually provide upto around 18W if i remember well.
Just get yourself an enclosure which provide both USB and firewire, and
use the firewire one on your mac.
Friendly,
Sven Luther
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