This tutorial is designed to save you the hassle and money of buying one of the commercial tools (xecuter ck3 + probe or maximus xtracotor + spear) which cost upwards of $40. ALL of these items can be salvaged out of old pc's or electronics or bought at radio shack for pretty cheap! Things needed: First gather all your components, 1x 10K resistor (marked brown black orange gold) 1x 1k resistor (marked brown black red gold) 1x NPN signal transistor (eg: BC546/7/8/9 BC337/8 C945 2N2222 1x DB9 female serial plug some lengths of wire a needle for the probe / a multimeter probe / sharpen the leg of a resistor Tools: soldering iron and damp sponge (15 Watt or adjustable heat setting) solder (0.5mm flux cored is good) some electrical tape / hot glue / shrink-wrap tubes to tidy everything up to your taste. You will also need a PC with a rs232 serial port (9 pin socket, looks like a vga port) if you don't have a serial port you can use a usb to serial adapter( USB to RS232 Serial Port Adapter) CLICK HERE ----Note that this won't work in dos. and you need to install drivers for windows. Assembling the lite-on probe: The transistor pictured here is a BC549 which shares the same CBE pinout as a BC547 Trim the transistor leads and bend up the base lead, then fit the transistor so that the collector sits in pin 2 and the emitter sits in pin 5 When soldering the transistor, heat up the joint while applying solder, don't leave the iron on the joint for more than a few seconds. Solder the 1K resistor to the joint at pin 2 and the 10k resistor to the base lead. when soldering the 10k it is best to 'tin' both leads first to get some solder on the leads. Tin the ends of three wires by heating the wire while applying solder Then solder the wires to their joints as shown. Get a sewing needle and put the other end of the probe wire through the eye, wrapping the wire around the needle, then solder this for a good connection. If you have a crocodile clip, solder this to the ground wire for easy grounding of the drive. insulate the bare wires to prevent shorting. Especially make sure the 5V joint at the 1K resistor (red wire in my circuit) is insulated, if this wire shorts out it can damage your circuit and/or computer and/or drive. Hot glue is great. Video TUT--- this is not my vid just added this to show you some hands on. [ame]http://www.youtube.com/watch?v=esjjdMpjpKQ&feature=fvw[/ame] Also will post part 2 in a seprate tut on How to Flash your lite-on 74850C. Please +rep if this helped you! Hope this Helps and saves you some money. Also I do not take any responsibly for any damage done to you Drive or self, this is for pure informational purpose only. Thanks to yaywoop for the pics.