View Full Version : 10 Feet Long USB 2.0 A to A (Male to Female) Extension
04-07-2003, 09:26 PM
Back in stock:
Get them while they are hot.
Price: $1.65 each. I ordered 10 and it came to $23.65 with shipping.
04-08-2003, 10:55 AM
04-08-2003, 03:57 PM
Compgeek's page states "USB 2.0 compliant".
Bullsh*t. There's no way such a cable can be compliant when the USB specs (both 1.1 and 2.0) explicitly prohibit extension cables.
From the USB 2.0 spec (http://www.usb.org/developers/docs), page 92, section 6.4.4 "Prohibited Cable Assemblies":
USB is optimized for ease of use. The expectation is that if the device can be plugged in, it will work. By specification, the only conditions that prevent a USB device from being successfully utilized are lack of power, lack of bandwidth, and excessive topology depth. These conditions are well understood
by the system software.
Prohibited cable assemblies may work in some situations, but they cannot be guaranteed to work in all instances.
Extension cable assembly
A cable assembly that provides a Series “A” plug with a series “A” receptacle or a Series “B” plug with a Series “B” receptacle. This allows multiple cable segments to be connected together, possibly exceeding the maximum permissible cable length.
Don't get me wrong - compgeeks is a great company to deal with, but products like this just make USB harder than it needs to be.
04-08-2003, 06:41 PM
Eh... If you have a need and this fills that need, so be it.
I agree that they shouldn't claim it's compliant with the standard if it's not, but they prolly mean that it's heavy enough to pull high throughput (2.0).
04-09-2003, 12:07 PM
"Prohibited cable assemblies may work in some situations, but they cannot be guaranteed to work in all instances.
Extension cable assembly
A cable assembly that provides a Series “A” plug with a series “A” receptacle or a Series “B” plug with a Series “B” receptacle. This allows multiple cable segments to be connected together, possibly exceeding the maximum permissible cable length."
According to your quote this is only a problem if you exceed the "maximum permissible cable length". USB2.0 specs from 2002_05_28_errata (file aquired through your link to USB 2.0 spec) states that cables up to 5 meters in length are allowed. So in most cases this shouldn't be a problem, as to signal loss from the extra connector it shouldn't be any worse than using a hub, as the hub acts like an extension itself.
04-10-2003, 04:45 PM
It's a problem if you exceed the maximum cable length, or if the connector in the middle of the cable introduces some nasty stuff like an impedance mismatch or extra capacitance, which aren't accounted for as you're only supposed to use single cables.
The idea behind USB is that it should be as simple as possible - it shouldn't be up to the user to have to watch out for this stuff. A USB bus should ideally consist of stages where there's a single cable between each hub, and a single cable to each device.
The fact that products like this even exist means that someone out there decided to throw away the spec. If they're willing to do this with cables, what does that say about more complicated devices?
What about the warnings in a lot of devices' manuals about not being used with a hub - they're definitely not compliant, as compliance requires that a device work on the end of a chain of hubs.
Oh, and don't even get me started on the likes of non-compliant hubs. :D
04-10-2003, 04:49 PM
A lot of those USB Pen's come with and use those cables.
So they must not be compliant either...:)
04-13-2003, 01:26 PM
Any free shipping coupon?
04-15-2003, 12:29 PM
I can't get into touch with u. You nmailbox might be full. Please give me another email address. Thanks.
Powered by vBulletin® Version 4.1.12 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.