USB cables: Difference between 1.1 and 2.0 ???

  • Thread starter Thread starter Thomas G. Marshall
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Thomas G. Marshall

Curious....

I used an *old USB cable* to connect my laptop's USB 2 port to a USB 2
device.

I got a WinXP message (seemingly a little wrong) which claimed that I was
using a low speed USB port and that moving the cable to a high speed port
would result in higher rates.

Bunch of questions, given that I cannot find cable wiring differences
online.

1. Is there a difference between cables.

2. Did Windows XP get confused and respond to the slow cable as if it were
instead a slow port. This seems like a silly error message.

3. Possibly unrelated: There is a lumpy thing on the cable near the B side.
Reminds me of the ferrite core that I saw on my atari-800 video out cable.
(stop snickering). The usb cable loops through it once. What is it, and is
this related to shielding, emmissions, indirectly speed, or what?

Thanks guys
 
Thomas G. Marshall said:
Curious....

I used an *old USB cable* to connect my laptop's USB 2 port to a USB 2
device.

I got a WinXP message (seemingly a little wrong) which claimed that I was
using a low speed USB port and that moving the cable to a high speed port
would result in higher rates.

Bunch of questions, given that I cannot find cable wiring differences
online.

1. Is there a difference between cables.
Click to expand...

No. Any proper USB1 cable can be used for USB2. Since USB2 is pickier, it's
possible that a bad cable work work for USB1 and fail for USB2.
2. Did Windows XP get confused and respond to the slow cable as if it were
instead a slow port. This seems like a silly error message.
Click to expand...

This could happen if you had a bad cable, I assume. Do you get this message
when using other USB cables?
3. Possibly unrelated: There is a lumpy thing on the cable near the B
side. Reminds me of the ferrite core that I saw on my atari-800 video out
cable. (stop snickering). The usb cable loops through it once. What is
it, and is this related to shielding, emmissions, indirectly speed, or
what?
Click to expand...

Just cuts down on RF leakage. Should not affect speeds, etc.
 
Curious....

I used an *old USB cable* to connect my laptop's USB 2 port to a USB 2
device.

I got a WinXP message (seemingly a little wrong) which claimed that I was
using a low speed USB port and that moving the cable to a high speed port
would result in higher rates.
Click to expand...


Usually this means you don't have the proper USB2 driver
installed for USB so it's running in USB1 mode regardless of
the cable.
 
In comp.sys.ibm.pc.hardware.misc Thomas G. Marshall said:
Curious....
Click to expand...
I used an *old USB cable* to connect my laptop's USB 2 port to a USB 2
device.
Click to expand...
I got a WinXP message (seemingly a little wrong) which claimed that I was
using a low speed USB port and that moving the cable to a high speed port
would result in higher rates.
Click to expand...
Bunch of questions, given that I cannot find cable wiring differences
online.
Click to expand...
1. Is there a difference between cables.
Click to expand...

Officially: no. Practically: sometimes. I have had some older USB cables
that produced interface errors with USB 2.0. Using an USB 2.0 cable
(or simply a new USB cable) removed the problem in each case. My
theory is that these were actually substandard USB cables and that
with USB 1.0/1.1 the difference was not large enough to cuase problems,
wile with USB 2.0 it was.
2. Did Windows XP get confused and respond to the slow cable as if it were
instead a slow port. This seems like a silly error message.
Click to expand...

No. It is not possible to detect a substandard USB cable in software.
The only thing you may get is more transmission errors. XP is pretty
backwards with USB support. Typically USB 1.0/1.1 work out of the
box, but USB 2.0 may require a driver.
3. Possibly unrelated: There is a lumpy thing on the cable near the B side.
Reminds me of the ferrite core that I saw on my atari-800 video out cable.
(stop snickering). The usb cable loops through it once. What is it, and is
this related to shielding, emmissions, indirectly speed, or what?
Click to expand...

It is an EMI (Electro Magnetic Intererence) ferrite. It basically
blocks very high frequencies that could cause problems with radio
equipment. Often these are not really needed, and their use is a bit
of black magic. For example in many circuit diagramms you will
find them listed as "ferrite bead" or "bead <size>" without
the electrical characteristics being given.

Arno
 
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