dev builds
themes manual
device status forums
mailing lists
IRC bugs
dev guide

Rockbox mail archive

Subject: Re: First experience of iRiver H-140

Re: First experience of iRiver H-140

From: BlueChip <>
Date: Wed, 19 Jan 2005 01:12:37 +0000

Another point with all cables electrical, is DO NOT USE THEM COILED ...if
you have a retractable cable - ALWAYS fully extend it when in use -
especially if it is carrying mains current.

The electrical and magnetic interference not only cause signal quality
degradation (data signals) and "crosstalk" (audio signals) but also heat
(mains cables.)

There is NO physical difference between USB1.1 and USB2.0 cables, same
connector, same pinout, etc. But a very poor quality cable may be
only-just good enough to carry a USB1.1 signal ...and if that happens, the
USB2.0 _protocol_ hand-shake will fail (due to signal degradation in the
wire) and your device will resolve back down to USB1.1 (which is the nice
thing about USB2.0 - it is FULLY (afaik) backward compatable with USB1.1 -
"well done" to whoever did that!)


>Well, since USB 2.0 is (theoretical maximum) 24 times as fast as 1.1, the
>cables need to be better at some things (perhaps shielding or so). Just
>like you need qualified cables if you want Gbit networking.
>Neon John says he thinks most USB 1.1 cables are already good enough
>though. I myself have no experience with different cables.
>On Tue, 18 Jan 2005 18:14:13 -0600, Glenn at home
><> wrote:
>>I did not know that there is a different cable for USB 2.0 from 1.1.
>>----- Original Message -----
>>From: "Ronald Teune" <>
>>To: "Rockbox development" <>
>>Sent: Tuesday, January 18, 2005 5:36 AM
>>Subject: Re: First experience of iRiver H-140
>>quote from:
>>USB 1.1 compliant
>>Speed transfer rates up to 12 Mbps depending on USB version
>>Maximum conductivity and error-free data transmission
>>So, you're right, probably no USB 2.0 speeds possible. Too bad, because
>>this long cable is just... well... long.
>>On Tue, 18 Jan 2005 10:53:25 +0100, Johan Vromans <>
>>>Ed MacDaniel <> writes:
>>>>Howdy BC,
>>>>Will those retractable USB cables work OK for you?
>>>Retractable USB cables are usually very thin. I doubt they meet the
>>>USB 1.1 or 2.0 specs. AFAIK they are typically used for slow devices
>>>like mice.
>>>Please correct me if I'm wrong -- I'd be interested as well ;-).
>>>-- Johan
>icq: 211304012
>skype: zeekoe

Received on 2005-01-19

Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy