On my system (ASUS A8V motherboard with 6 out of a possible 8 USB ports
installed) the listing shows:
'USB Root Hub' (4 times)
'VIA Universal Host Controller' (3 times)
'VIA USB Enhanced Host Controller' (once)
Loads of newbie Questions:
1. What is a Hub and what is a Root Hub? Are they hardware, microcode or
software?
2. What is a USB port and how does it differ to a hub?
3. What is a Host Controller? Is it hardware, microcode or software?
4. I am right in assuming an Enhanced Host Controller is one which
provides USB 2.0 support, the others being USB 1.1 only?
5. Why does the output from SiSoft Sandra show no devices attached to
any of the 6 ports on the Enhanced Host Controller, but does show the
expected devices connected to either Port 1 or Port 2 on one of the
three Universal Host Controllers?
6. Why have I got 3 of these host controllers and not just 1 like the
Enhanced Host Controller?
7. What is 'Enumeration' and why would a device connected to a USB port
fail this process?
8. Is the driver that is listed in the properties for a Hub or Host
Controller part of Windows XP, or a specific piece of software supplied
with the device?
9. Why do some device have no such driver (for example the Nikon D80
DSLR camera which Windows XP will not recognise - but only on this
computer)?
Finally, why do so many people report a 'USB Device Not recognized'
error, across such a wide range of systems and devices, across so many
years, without a definitive solution being developed by the industry?
Microsoft's absence from the this scene is a disgrace. The cost to users
must run into 10's of thousands of man hours by now. There are thousands
of pages of guidance on the internet which range from the incredible to
the insightful - many of them contradicting others. None of them have
solved my specific example (but I've only been trying to solve this for
2 weeks ....). If we had this sort of problem with our cars, telephones,
TVs, etc, it would have been the subject of incisive media analysis. Why
do we let the computer industry get away with this situation? Nikon's
technical support response to the problem could form the script for a
Broadway comedy; it includes re-installing XP. Who is going to pay for that?
An USB2 controller has two logical 'incarnations', one for
USB2 and some for USB1. It depends on the attached device
which incarnation is used. The USB1 incarnations are usually
splitted, so each incarnation ususally has two ports.
Microsoft UVCView shows it:
http://www.microsoft.com/whdc/device/stream/vidcap/UVCView.mspx
With this tool you will see that the number of USB2 and USB1 ports
is equal because they are identical physical ports.
Uwe
I do not understand however why a known USB 2.0 device (my HP 8450
printer) is shown (in SiSoft Sandra) as being connected to a 1.1 Host
Controller and shown as having a connection running at 12 Mbps ("Full"
speed) when it should be shown connected to the Enhanced controller and
connected at (up to) 480 Mbps ("High" speed).
Uwe
"Ron" <R...@discussions.microsoft.com> wrote in message
news:ED27452B-2945-4A5F...@microsoft.com...