|
|
The message <467616cd$0$17942$4fafbaef@xxxxxxxxxxxxxxxxxxx>
from "Inty Trashtronics \(r\)" <intiglietta@xxxxxxxx> contains these words:
> "Johnny B Good" <jcs.computersbutt@xxxxxxxxxxxxxxxx> ha scritto nel
> messaggio news:31303030373730364675A3F844@xxxxxxxxxxxxxxxxxxx
> > There is the intel standard based on a 2 by 5 pin header with keypin
> > whereby the missing pin at the end of the row is next to the ground pin
> > for that row. Working from the end opposite to the key, each row starts
> > with 5v, D-, D+ then ground.
> Uhm...
> > There is a varient on this theme based on a 2 by 4 pin header whereby
> > the need for a key is neatly avoided by the fact that the pinouts in
> > each row run the opposite way round to the other row. When a matching
> > plug is used, all that can get switched around is which socket on the
> > backplate connects to which row.
> Something like this?
> 5V D- D+ GND
> GND D+ D- 5V?
Exactly like that! :-)
> > Then, of course, there's the "Heinz 57 Varieties" 'standard' which
> > matches none of the above. If in doubt, it's a fairly trivial task to
> > determine where the 5v and ground return pins are which just leaves the
> > 2 data pins to sort out.
> I've got a QDI P5I430VX, model name Explorer II.
> It's a Socket7 too.
> Near AT keyboard's connector there are two headers,
> one of which is the PS\2 i'm sure (it's a non-standard header with 5 pins,
> and the 2nd missing, as a key)
That single row 5 pin header for a PS/2 mouse socket bracket is pretty
common on a lot of AT MoBos of that period. However, the pinouts didn't
seem to conform to any common standard IME.
> and the other is 2x5 but there are two pins missing, in a row, like this
> O O
> O O
> O O
> - -
> O O
> Is this an USB? There's no mention of it in the manual, but i think it's an
> USB because the Triton 430VX has USB support..
You're probably right which would put that header layout firmly in the
"Heinz 57 Varieties" camp.
> > Sometimes, but not always, the MoBo manual might actually enumerate the
> > USB header pin functions (assuming you've got a manual to work from in
> > the first place).
> In a Lucky Star mod. 6LX2 the manual enumerates EVERY header on the board,
> even the AT and the ATX power IIRC,
> but no mention of the USB, there's only writtien that "the board has got an
> USB header.."
It's a , isn't it? Time to dig out the multimeter and buzz out
what pins are 5 v and what pins are 0v. As long as the 5v and 0v pins
are correctly wired, you can guess the data pins without hazarding the
test usb gadget.
There's plenty of talk about USB power being restricted to an initial
maximum of 100mA until the extra 400mA's worth has been negotiated for
by the attached device but, even today, the 5v pins seem to be simply
directly connected (hopefully via a 3A polyfuse :-) to the MoBo's 5v
rail.
In most cases, it's possible to positively identify which is 5v and
which is 0v out of the USB header pins by testing resistance to the
appropriate pins on a spare molex with the system disconnected from
power (the least hazardous way to probe around the innards of a PC with
test meter leads). Incidently, the data lines look like very high
resistance ground/5v return paths in this test.
HTH
--
Regards, John.
Please remove the "ohggcyht" before replying.
The address has been munged to reject Spam-bots.
|
|