PC - Passive circuit interface

[xcalx]

Hi All - I need some help/advice.
I'd like to connect a magnetic sensor (bicycle computer) directly to my computer through one of the ports without a power supply.

I found the attached circuit but don't know how to test it.

Can anyone make suggestions about circuit design - can I feed the wires directly into my parallel/serial port?

I'm also trying to write a program in VB6 to read the input, but not having much luck.

I'd really appreciate any help anyone could give me.
Thanks
Pete

 

[mneary]

Yes you can connect these signals directly to a serial port, as long as these are the only connections to the switches.

You'll have to get the spec for a 9-pin serial port, since 25-pin serial ports have been rare since about 1989. Map the signal names on the diagram to the signal names on the 9-pin version.