Thermaltake rotation's speed fan

[Shiva MahaDeva]

Hi all:

I bought a Thermaltake Smart II CPU fan to put un my Ultra 5
workstation.
This fan haves a third wire, to get fan's rotation speed, but Ultra 5
doesn't
haves this option. Is there any way to use paralell port to get third
wire data ? My friend told me that I could put a diode and a resistor
to
current`s limitation and connect in paralell port, but how could I
make this ?
Thanks in advance.

 

[bloo]

I guess that you have a 12v sqare signal about 5Khz. Maybe you can use
a 1N751A with a 10K in series to limit current and drop down to 5.1v.
I would choose serial over paralell port.

R 10K
[fan]---/\/\/\/\---+-----> to Serial
|
Zener /\
| Gnd
>From the bitter experience, build some optocoupler interface..