Different Apple machines, different USB behavior [ was: Re:
Powerbook5,7 [ ... ]
Reply-To:
In-Reply-To:
X-Spoken-Languages: en, de
X-URL: http://www.wolfgangpfeiffer.com
Hi Sven, Hi All
On Thu, May 24 2007, at 07:27 +0200, Sven Luther wrote:
> On Thu, May 24, 2007 at 01:16:24AM +0200, Wolfgang Pfeiffer wrote:
> > On Thu, May 24 2007, at 00:27 +0200, Wolfgang Pfeiffer wrote:
> >
> > > I have lots of problems connecting hardware to an AluBook 5.8. For both
> > > USB and Firewire enclosures.
> >
> > In order to not exaggerate: At least some USB enclosure works, provided
> > I connect it with 2(!) connectors to the alubook, and provided I plug
> > those in some correct order, whatever this is ...
>
> Well, this is the normal power limitation of the USB device, nothing to
> be worried about. An USB connected external disk powered from only the
> USB connector *CANNOT* work.
I've tested it, and all I can say by now: No. With "No" I'm referring
to the part where you say it "*CANNOT* work"
Short version first:
I need some external power supply for a USB disk enclosure if I want
to connect the disk inside to the newer Alubook 5,8. I don't need the
power supply if I connect the same disk enclosure with the same cable
to my old Titanium IV.
Details:
2 computers being involved: an old Titanium IV and a newer Alubook5.8.
Plus a 40 GB Hitachi disk inside a USB enclosure. The Hitachi has a
few ext3 partitions on it, with data on it. Both computers have
exactly the same self-rolled kernel installed, with some relatively
fresh unstable Debian on both of them.
I made a picture of the USB enclosure, with the cable I used
plugged in:
http://wolfgangpfeiffer.com/usb.enclosure.jpg
As you can see by the picture, the USB cable end that can be connected
to computers is forked into 2 USB connectors. You have at least 2
choices to connect the USB-disk to some computer:
*** 1:
Via an external power supply:
Joining the 2 USB connectors, that are connected via the black/red
cables, i.e. "daisy-chaining" them. Then connecting the resulting "one"
USB connector to some AC powered USB Hub. The USB Hub in turn, via an
additional USB cable, is connected to the computer where the USB disk
should be connected to.
*** 2:
Without an external power supply:
Joining the 2 USB connectors as in #1 ("Daisy-chain"). But this time
connecting the resulting one USB connector directly to the computer,
thus omitting the USB Hub.
Results:
Option 1 enables working disk connections (i.e. /dev/sda is showing
up) to both the Titanium or the alubook.
Option 2 enables a working disk connection only to the Titanium.
Now here comes my favorite part:
The older well-behaving Titanium has 12-Mbps USB 1.1 ports. The newer
Alubook 480-Mbps USB 2.0 ports.
Anyone out there who wants to know why I'm not that much unhappy
because I wasn't successful when trying (not really hard, but anyway
...) to sell my old TiIV-book? ... :)
Whatever: I recommend being careful when buying additional hardware
for Apple machines.
Nice week-end to everyone out there :)
Best Regards
Wolfgang
--
Wolfgang Pfeiffer: /ICQ: 286585973/ + + + /AIM: crashinglinux/
http://profiles.yahoo.com/wolfgangpfeiffer
I made slight changes on Key ID: E3037113. Please refresh it.
http://keyserver.mine.nu/pks/lookup?search=0xE3037113&fingerprint=on
Reply to: