Archived from groups: alt.comp.periphs.mainboard.asus (
More info?)
Paul wrote:
> In article <cipq4s$9s5$1@nemesis.news.tpi.pl>, geos <geos@nowhere.org> wrote:
>
>
>>hello,
>>
>>after some summer break I come back to the idea of modding my old p2b-d.
>>I reviewed the document here
http://tipperlinne.com/p2b-ds150.htm and
>>want to make myself sure wheater the connections between pins are as
>>follows:
>>
>>http://www.geocities.com/qroobas/ds-before.jpg
>>
>>I would use 2-pin FS3 instead of 3-pin if the third pin, the rightmost
>>one, is unused. I would appreciate confirmation of these connections by
>>the author or Paul or somebody, who has done such modification.
>>
>>thanks,
>>geos
>
>
> This is my previous post:
>
>
http://groups.google.com/groups?selm=nospam-3107040650380001%40192.168.1.177
>
> This is a schematic diagram of the wiring.
>
> +3.3V
> +3.3V ---X |
> 10K |
> X----/\/\/\---+ \ (Internal
> "strap" | / 240K
> GND ---X | \ Pullup
> ------------- | / Resistor)
> | | |
> | | | 22 ohm
> PCICLK0 |----+--+--/\/\/\---------> Clock to PCI slot
> | Series
> | Damping
> ------------- Resistor ("R99")
>
The internal resistor is actually a pull-down - that's why FS3 defaults
to logic 0 when FS3 is omitted entirely (i.e. as shipped by Asus).
> Now, we redraw it physically:
>
> +-------------------------------------
> | |
> | |
> 10K ----------- | New
> Resistor | | X X X FS3
> | | 9250 | | |
> ------R99---+-------Pin9| Clock | | |
> 22ohm PCICLK0| Gen | +----+ |
> | | | +----+
> ----------- | |
> X X X FS0
> X X X FS1
> X X X FS2
> (+3.3) (GND)
>
> All three pins of the new header are used. The end pins of FS3
> are feeding from the end pins of FS0. All the left hand side
> FS pins are at 3.3V, and the right hand ones are at GND potential.
> The long wire goes from the center pin of FS3, to the end of the
> new 10K ohm resistor. The other end of the 10K ohm resistor is
> soldered to the junction of R99 (where the right hand side of
> R99 is soldered to its pad). This keeps the bottom end of the
> 10K resistor close to the circuit, keeping the stub length down.
> The wire going from the top of the 10K resistor isn't critical, so it
> doesn't have to be strung like a guitar string. Neither are the
> two wires running from the left and right header pins of FS3,
> when they connect to the left and right header pins on FS0.
>
> The photograph from Tipperlinne is deceptive and the photo should
> have been taken before the hot glue was added, or at least the
> solder joints should have been visible.
Fair comment - I'll try to get a better picture next time I do one.
> HTH,
> Paul