Thread
:
USB Case Connections
View Single Post
#
3
October 26th 03, 12:54 PM
Matt
external usenet poster
Posts: n/a
On 24 Oct 2003 04:59:54 -0700,
(Howard) wrote:
I am having some trouble understanding the connections from my Lian Li
front USB ports to the motherboard. However, checking back on a
number of prior posts from this group has been very helpful and pretty
much explains the connections. I would just like to check with you
folks to make absolutely certain I understand one point.
The two ports on the case front each have cable coming from them...one
port has a cable with 4 connectors and one port a cable with 5
connectors. I was originally quite confused as to why the ports would
have different numbers of cables until I came to the conclusion that
these 9 connectors all attach to one Front USB 'Header' on the
motherboard and that the 2 ports in fact are attached in a way that
the motherboard'thinks' is just one port..ie the 2 ports are defined
as one front case USB connector. Is this correct?
Not really - Each USB port is 4 independent connections, and the most
common order for the 4 is -
+5v, D-, D+, 0v
The extra one in a 5, is usually an additional (chassis) Ground -
though some boards seem to have an overcurrent warning signal ...
this should NOT be connected to an extra ground.
Motherboards lay out the ports in various ways.
1. 2 independent lines of 4 or 5
2. A block of 8 or 10, with the two lines going the same way, or
opposite.
3. There ARE layouts incompatible the common 4/5 way alignment.
--
I may be dozzzy, but take the ZZZ's out to mail me
http://www.junkroom.freeserve.co.uk/jvc2080.htm
- 2x2x24 CD-RW troubles
If you drop a cactus, don't try to catch it!
Matt