I would like instructions on wiring up a null modem cable with the wire# to pin# for a DB9 RS232C My DB9 connector looks something like this (dots '.' are added as space holders): .............................. |------| ............|------------------|.......|--. (a) ------.|..................|.......|..| ----- (b) ............|------------------|.......|--' .............................. |------| (a) ____ [ ,,,,,, ] telephone like jack .'-------' (b) ___________ \.o.o.o.o.o.../ female head .\_o.o.o.o_/

Go to Radio Shack and buy either a null modem cable or a null modem plug. P.S. diagram B resembles DB9, I don't understand the first one at all, and anything that resembles a telephone jack isn't DB9 and probably isn't compatible.

What are you trying to do, hook two computers together? Serial ports are 1/8 the speed of parallel ports. Get a laplink style cable for your p-ports (two male ends).

Anyhow - as you requested. RS232C Serial Ports - No handshaking DB9 to DB9 3--------2 2--------3 5--------5 DB25 to DB25 2--------3 3--------2 7--------7 DB9 to DB25 3--------3 2--------2 5--------7 Parallel Null Cable 2-------15 15--------2 3-------13 13--------3 4-------12 12--------4 5-------10 10--------5 6-------11 11--------6 25-------25 Crossover Twisted Pair for NIC's RJ45 (Looks like 8 pin telephone plug) 1--------3 2--------6 3--------1 4--------7 5--------8 6--------2 7--------4 8--------5 I hope this helps, but you can't mix RS232C and RJ45 ports. Good Luck