What is the JTAG Hack?
This is a new hack which can boot homebrew code in less than 5 seconds. For now, all we need to know is that this is a new way to exploit the well-known 4532 kernel, in a way which also works on updated machines, unless they have been updated by the summer '09 update. It also works on all hardware types.
What does the JTAG Hack require?
1. The hack requires a console that has not been updated to the August09 dashboard. Although some consoles with the 7371 kernel have already been patched to stop the JTAG hack. To find out what dashboard you have, turn on the System and navigate to the Settings. In there, hit "Console Settings". Now highlight "System Info". On the right side you'll see the Dashboard bum nuts
Version. This version must be lower than 2.0.7xxx, otherwise homebrew won't work.
2. Some soldering skills.
3. A computer with a LPT(printer) port or a USB Flasher.
What does the JTAG hack allow me to do?
The hack allows you to run unsigned code also known as homebrew. Homebrew code allows the Xbox 360 console to do extended features outside what was planned by the manufacturer (Microsoft). e.g. Running Applications, Emulators, Linux, File browser capabilities, loaders for XEX (the 360 executable file), Copying Games from DVD to HDD and much more. The term (home brew) means software which wasn't made by a large company or organisation however is simply made at home by a individual or team of people (usually enthusiast or students)
Homebrew capabilities are really limitless, as it depends on the scene to make releases, many members of forums have made their own programming teams some work individually.
At the current moment the JTAG allows to following extended features:
Linux Support - Gentoo or Ubuntu - Full CPU support finds 3 CPU XENON cores, only lately has the distrubution of Linux been able to have full support as a member of Xbox-scene has found a driver which works with the Xbox 360. Unfortunately No Sound Drivers are yet known of however the scene is slowly developing.
Run Games from Hard Drive or USB devices - There is various application for Homebrew enabled Jtag 360's which allows you to launch XEX files as well as convert them to games on demand so they could be read straight from the NXE dashboard. These games can then be transferred onto USB pendrive, hard drive or Xbox 360 Hard drive. Some programs which allow you to launch XEX files are XEXloader, XEX Menu.
Convert Xbox Live Arcade Demos to Full Version - With XM360 (Homebrew Application) for Xbox 360 consoles, you are able to convert Xbox Live Arcade Demos into the real full version thing. Excellent for everyone who enjoys those minigames.
Alternative Dashboards - Many teams are starting to create thier own dashboard like they have with the original Xbox console. These Dashboard also allow extended features such as FTP support, full file manager, temperature, fan control, launch homebrew and many more features. Some of the most known alternative dashboards are Freestyle Dash, XEXDash. 360 Menu and Ingenious.
Unban your System from Live - The Xbox 360 console has a Unique ID which allow Microsoft to determined whether it has been banned or not. This is your Console serial number and Mac address. The Jtag hack also allows you to change addresses which associate your unique console with Xbox Live. This is held within the NAND chip. This information is also known as your Keyvaults.
READ or CHANGE DVD KEY - There are many motherboards out there where the DVD key has been lost and the motherboard has become useless. With the Jtag hack you could change all of this. This is achieved by flashing Xellous onto your NAND chip. Xellous allows you to view your CPU key as well as DVD key. There is also another application which may help you with this task and is called Flash 360.
Preforming the JTAG hack.
There is a large amount of JTAGing tutorials out there so no need to reinvent the wheel so here are a few links to ones i have found helpful. Allez l'OM ! 8--->
free60 good resource.