All current chips (bar an odd firmware one that is not really relevant here as games are not the focus of it, it remains to be seen what will come of the recent developments) attach to the disc drive of the wii (just quickly there are 4 sorts: DMS, d2a, d2b and d2c. The first three are not a problem (bar some of the later d2b chips which ship with cut pins
d2c chips are what is used in recent model wiis and presently only supported by the commercial offerings of the d2ckey and infectus (
http://www.infectus.biz/news.php , I have not followed this chip though and they say they do open firmware and the like)
They all alter the commands to allow reading of burnt discs (as well as other stuff like adding dual layer support and partial region free of Wii and GC (read up on this elsewhere as it is important and updates from different region titles can cause major headaches with so called semi brick wiis and duplicate channels)).
Updating: some of the chips also update by DVD (this is a feature added later to the open source chips), others by programmer or even stuff like serial cables wired inside the case (or outside if you do something like this:
http://wii.scorpei.com/Guides_external-TSSP.html )
The chips themselves are small programmable chips (what sort there is depends on the code you use, PIC microcontrollers are arguably the most common for the open source crowd). They are usually standalone but some people add capacitors and the like to tweak things (they should work fine without it though).
As for updating I briefly mentioned it but:
You can buy some preprogrammed and thus update by DVD, check the support forum of your chosen chip here and
http://www.eurasia.nu/shop/default.php also sell a few for not much money (presently the YAOSM (one of the best open source chips) goes for $6 US)
You can buy a programmer to work out of the box (normally around $30-40 but it has been some time since I did electronics of this grade in Canada). They usually come in USB and serial flavours with prices usually being higher for the USB variety.
You can build a programmer. Nothing special on the difficulty front assuming you can solder to a bit of stripboard or use a breadboard and read a simple electrical diagram (
http://www.bobblick.com/techref/projects/p...og/f84pgmsc.gif is perhaps as complex as it gets and most are far simpler) and parts will probably be cheaper than a premade one. Your options here are you can build one straight up from parts you source yourself or buy a kit:
http://www.electronic-kits-and-projects.co...programmers.htm (UK site but it should give you and idea)). Depending on what you have floating around it can be very cheap and there is nothing stopping you from selling them to your friends.
