Neo-x
Neo Technologies, best known perhaps for their successful PS/2 modchips, were the first to successful give a public demonstration of a working XBox chip on 04/05/2002 at Bowlers computer fair in Manchester UK. Unfortunately, due to legal issues encountered with Sony over the PS/2 Neo chips, Neo Technologies have stepped down and decided not to publicly release any XBox modchip.

X-tender
X-tender was the first team to make an XBox chip available to the public. However there was some controversy when it was realised that the chip was essentially still in beta and did not work with a number of released games. The problem games were re-released and the chip was reworked so that the problem should not happen again.

Enigmah
Enigmah team have been very patient in ensuring the final chip works correctly. Beta's were sent out and tested extensively for weeks before a final retail version of the chip was released. Though the first retail batch contains a PCB flaw requiring slight modifications to the fitting. Version 2 of the board (identified on the PCB) is slightly easier to fit. The Enigmah team is also working on various software tools.

Self burnt chips
Recently the X-tender chip code was cracked and released to the public domain. It essentially allows people with the right tools and enough motivation to code their own mod-chips. In the long term it may lead to professional modders flashing the XBox bios whilst it is still on the mainboard, removing the need for a mod chip to be fitted at all. For the average joe however it should not be considered as a 'cheap alternative'. It is still much easier, and not much more expensive, to buy an official chip. Therefore this FAQ does not go into detail on how to flash eeproms etc.

Chip features
Most chips seem to offer the same features;
Play original import games
Direct boot backups from CDr/CDrw/DVDr/DVDrw
Allow unsigned code to run (homebrew tools/games)
Macrovision off (play DVD films through video)

Both Enigmah and X-tender are currently 29 wire mods.

Problems
Early xtender chips had problems with numerous releases, leading to many being re-released as 'proper's. Beta enigmah chips had problems with 3 releases which could be patched easily. Both chips, now in final retail version, can play all releases flawlessly.

It would appear that the laser unit in some XBoxes are of a better quality than others. As a consequence you may find that your xbox is fussy with which CDr/DVDr media it will read. Using high quality (branded) media is no guarantee that your xbox will have better success. Users with poor laser units may find that cheap DVDr media gives better results. As an alternative it is possible to open up the xbox and tweak the laser power. Though this still does not guarantee a 100% sucess rate, it may improve things considerably.

Fitting the chips
Opening the XBox is relatively easy. The six screw points are hidden under stickers and the four padded feet on the underside of the XBox. A starpoint screwhead is required. Once opened the XBox needs disasembling almost entirely to access the underside of the main board, which is where the chips solder to.
All the solder points within the XBox are soldered pads, and easily accessible. Relatively experienced solderers, with patience and a steady hand should have no problems following the guides to solder to points that are roughly 1 mm in diameter, aproximately the size of the 'full stop' dot on a keyboard. A low powered (15 Watt) soldering iron is ideal.

Once rebuilt you may find your XBox does not power on correctly, flashes the power light red, or may not eject the disc drive. If this is the case then recheck all your solderpoints. If possible use a multi-meter to check that there are no crossed joints (two points soldered together). The XBox seems pretty resilient to bodged installs so don't panic if things dont go right first time.

Games
Cracked games were released on 04/05/2002. ProjectX made the breakthrough and released around 40 games over a 2 day period. Games have been released as both full dvd rips (up to 4 GB in size), and as CD sized rips with movies and music downsampled or removed alltogether.

Other releases
The Enigmah team have already released a tool to switch the XBox between NTSC and PAL. Further releases from Enigmah are promised, with a S/VCD player and a DivX player in the works. The chips really do open the door for homebrew developers who are now able to release 'unsigned code'.

Burning
Prassi PrimoDVD is recomended as the DVD burning tool of choice. Write using MODE1/2048. CD sized rips can be burnt with Nero, Diskjuggler or a number of other apps. Again, write in MODE1/2048.
DVDrw discs seem to be most reliable, though some XBoxes may work flawlessly with all media, including cheap unbranded DVDr. CRr/w may work for the CD sized releases. There really is no way of knowing without testing each individual XBox. If your XBox plays Audio on a particular brand of CDr/etc it does not guarantee that data/games written to the same CDr/etc brand will work - as Audio is read at 1* whereas data may be read at higher speeds.

Both DVD+r and DVD-r formats are supported by the XBox. The DVD-r Pioneer A04 (104) writer seems to be a popular choice.

CDr/w discs will take longer to load than DVDr/w discs. CDr/w also seem to be less reliable.