Step 2: Getting your parts
Computer with LPT port.
1x 25 pin d-sub connector (male or female depending on which kind of cable you have)
Digikey # 225FE-ND
1x 25 pin d-sub cable (lpt cable) You can actually skip the cable if you buy a male connector and make your wires long enough to extend from your xbox to the computer
Digikey # AE9863-ND
3x 330 ohm resistors (only for Xenon motherboards)
Digikey # P330BBCT-ND
1x 1n4148 switching diode (if you have Zephyr, Falcon, Opus or a Jasper get 3x of these)
Refer to the image below to tell what kind of 360 you have.
There has been a new update to the standard wiring you should use for the JTAG wiring on Xenon's which requires just 2x 1n4148 diodes. I've never used this method before so I can't really help as much if you have problems. But I would suggest going with it instead since it is supposed to be electrically superior and uses less parts so less room for failure I guess.