Connection Problem

i have made one arduino serial in one breadboard and i have some problems because i can't get connected with my pc...
how can i make one db9 cable to connect to my pc?
i´m running in windos 98 because in XP there is some problems with the data sending to db9 and db25...

please help me... (it's for one school project...)

Data sent to and from the PC is in RS232 voltages, coming out of the Arduino, and going into it is in logic voltages. You need a TTL to RS232 voltage converter, something like a Max232 chip.

Do you have an RS-232 level convertor chip? E.g. a MAX232 or something similar?

http://www.seattlerobotics.org/encoder/aug97/cable.html
this is a way using the max chip

This is another way using no IC, just transistor and diode