I have decided to start a thread devoted to modding consoles (softmods and modchips), though it will be more about the options available to you than a how-to guide (unless people want that).
There are a huge amount of threads about modding consoles, I'm just attempting to consolidate them all into one large thread.
Please ask questions, if I can't answer them I'm sure someone else will and I will update the first post (this one) with the answer.
Also if you have any suggestions or corrections.
I will get this thread started with two consoles. I will add to and amend this thread on a daily basis.
Microsoft Xbox:
Modchip - Modchips are available for all version Xbox consoles. v1.6 and v1.6b require the LPC on the underside of the console re-wiring before the modchip is installed. Use of a modchip online usually bans your consoles for Xbox Live.
Softmod - There are exploits in three games (Splinter Cell, Mechassault and 007: Agent Under Fire) that allow you it install a new dashboard to the internal HDD. All consoles can run the softmods.
Microsoft Xbox 360:
Drive Flash - Flashing the firmware on the Xbox 360 DVD drive is a fast way to play backups. There are a few limitations with drive flashing including having to keep the firmware up to date if you play online (and restoring it if you need to send you Xbox back to MS), it doesn't allow different region coded games, it doesn't allow unsigned code (such as new dashboards) to be run and not all drives are supported directly (new drives take time to hack). The Hitachi 79 drive requires a passkey device that needs to be soldered onto the drive before flashing.
Modchip - A few modchips exist but are largely redundant due to drive flashing.
-----------------------------------
Nintendo GameCube:
The GameCube uses an 8cm DVD varient for its games and as such full sized DVDs won't fit into a normal GameCube lid, there are lids available that allow full sized 12cm DVDs to fit but the GameCube laser isn't able to read past the 1.5GB (1.37GiB) limit. Also most GameCube's need the POT tweaked before backup discs will run successfully, this involves turning a potentiometer on the underside of the drive unit, there is no magic number to turn it to that works for all units.
Modchip - Modchips for the GameCube come it two types, ones that connect direct to the motherboard and those that connect to the drive unit. The drive unit mod chips are usually cheaper, easier to install but limited to running backups and aren't updatable unlike the more expensive modchips that are installed to the motherboard.
SDLoad - Using an Action Replay and an SD memory card adaptor you can boot a program called SDLoad from an SD memory card. From SDLoad game loaders and emulators could be run, allowing backups to be run.
BBA/Phantasy Star Online - Using a broadband adaptor and a copy of Phantasy Star Online you can stream games over a network to the GameCube. This method was the first be used to play backups but due to the slow speed at which the broadband adaptor worked the results varied from title to title.
Switch - The Gamecube can be modified with a switch to change from NTSC-U to NTSC-J and vise versa. This is only available on NTSC-U and NTSC-J consoles, PAL can't be modded this way. You will need a separate memory card for Japanese and US save games.
Nintendo Wii:
Modchip - A modchip is the only way currently. There are different modchips available for the Wii. The most important factor in choosing a modchip is the drive type your Wii has, although with the current generation of modchips this isn't much of an issue.
-----------------------------------
Sega Saturn:
Sega Dreamcast:
Out the box the Dreamcast can play backups, you will need either a boot disc (downloaded and burnt yourself) or a self booting game to play backups.
I have heard that the MIL-CD hole was closed for the last batch of US console and there is a way to get around it but I don't have confirmed details on that yet.
-----------------------------------
Sony PlayStation:
Modchip - Modchips are available for all version PS1 consoles including the PSone.
Swap Disc - Swap Discs are available for all version PS1 consoles including the PSone.
Sony PlayStation 2:
All version consoles are capable of playing backups the methods include:
Modchip - All versions support a modchip. There are many modchips with difference features.
From HDD - All versions can use a HDD, some models don't support internal drives and compatibility on the USB HDD loaders isn't as high.
Japanese models SCPH-10000, SCPH-15000, and SCPH-18000 (v0) can't have an internal HDDs due to the lack of internal bay.
Slimline (aka PStwo) PS2's don't have an internal bay but the SCPH-7000x and SCPH-70001 (v12-v13) can have an adaptor installed to take an internal HDD, there is also a special case to allow this.
Swap Disc - All versions support swap discs and they require another tool for opening the tray or lid without resetting the TOC. They don't work with DL (DVD-9) backups.
Independence Exploit - Doesn't work on Slimline consoles. Similar to the swap disc, you use a PS1 game to boot a special file on the memory card, from there you can boot backups.
Memor 32 - The newly released Memor 32 can be flashed with a 3rd party BIOS called Memento which gives it similar functionality to a modchip and boots backups directly. Currently Memento is only available for in PAL.
Sony PlayStation 3:
Games have been dumped but there isn't currently a method to play backups. You can play PS1/PS2 backups, but it requires soldering a switch into the PS3 and having a disc to load a TOC from (the disc itself doesn't need to be booted, just inserted whilst on the XMB). This method has been confirmed to work up to firmware 2.0.1.
There are a huge amount of threads about modding consoles, I'm just attempting to consolidate them all into one large thread.
Please ask questions, if I can't answer them I'm sure someone else will and I will update the first post (this one) with the answer.
Also if you have any suggestions or corrections.
I will get this thread started with two consoles. I will add to and amend this thread on a daily basis.
Microsoft Xbox:
Modchip - Modchips are available for all version Xbox consoles. v1.6 and v1.6b require the LPC on the underside of the console re-wiring before the modchip is installed. Use of a modchip online usually bans your consoles for Xbox Live.
Softmod - There are exploits in three games (Splinter Cell, Mechassault and 007: Agent Under Fire) that allow you it install a new dashboard to the internal HDD. All consoles can run the softmods.
Microsoft Xbox 360:
Drive Flash - Flashing the firmware on the Xbox 360 DVD drive is a fast way to play backups. There are a few limitations with drive flashing including having to keep the firmware up to date if you play online (and restoring it if you need to send you Xbox back to MS), it doesn't allow different region coded games, it doesn't allow unsigned code (such as new dashboards) to be run and not all drives are supported directly (new drives take time to hack). The Hitachi 79 drive requires a passkey device that needs to be soldered onto the drive before flashing.
Modchip - A few modchips exist but are largely redundant due to drive flashing.
-----------------------------------
Nintendo GameCube:
The GameCube uses an 8cm DVD varient for its games and as such full sized DVDs won't fit into a normal GameCube lid, there are lids available that allow full sized 12cm DVDs to fit but the GameCube laser isn't able to read past the 1.5GB (1.37GiB) limit. Also most GameCube's need the POT tweaked before backup discs will run successfully, this involves turning a potentiometer on the underside of the drive unit, there is no magic number to turn it to that works for all units.
Modchip - Modchips for the GameCube come it two types, ones that connect direct to the motherboard and those that connect to the drive unit. The drive unit mod chips are usually cheaper, easier to install but limited to running backups and aren't updatable unlike the more expensive modchips that are installed to the motherboard.
SDLoad - Using an Action Replay and an SD memory card adaptor you can boot a program called SDLoad from an SD memory card. From SDLoad game loaders and emulators could be run, allowing backups to be run.
BBA/Phantasy Star Online - Using a broadband adaptor and a copy of Phantasy Star Online you can stream games over a network to the GameCube. This method was the first be used to play backups but due to the slow speed at which the broadband adaptor worked the results varied from title to title.
Switch - The Gamecube can be modified with a switch to change from NTSC-U to NTSC-J and vise versa. This is only available on NTSC-U and NTSC-J consoles, PAL can't be modded this way. You will need a separate memory card for Japanese and US save games.
Nintendo Wii:
Modchip - A modchip is the only way currently. There are different modchips available for the Wii. The most important factor in choosing a modchip is the drive type your Wii has, although with the current generation of modchips this isn't much of an issue.
-----------------------------------
Sega Saturn:
Sega Dreamcast:
Out the box the Dreamcast can play backups, you will need either a boot disc (downloaded and burnt yourself) or a self booting game to play backups.
I have heard that the MIL-CD hole was closed for the last batch of US console and there is a way to get around it but I don't have confirmed details on that yet.
-----------------------------------
Sony PlayStation:
Modchip - Modchips are available for all version PS1 consoles including the PSone.
Swap Disc - Swap Discs are available for all version PS1 consoles including the PSone.
Sony PlayStation 2:
All version consoles are capable of playing backups the methods include:
Modchip - All versions support a modchip. There are many modchips with difference features.
From HDD - All versions can use a HDD, some models don't support internal drives and compatibility on the USB HDD loaders isn't as high.
Japanese models SCPH-10000, SCPH-15000, and SCPH-18000 (v0) can't have an internal HDDs due to the lack of internal bay.
Slimline (aka PStwo) PS2's don't have an internal bay but the SCPH-7000x and SCPH-70001 (v12-v13) can have an adaptor installed to take an internal HDD, there is also a special case to allow this.
Swap Disc - All versions support swap discs and they require another tool for opening the tray or lid without resetting the TOC. They don't work with DL (DVD-9) backups.
Independence Exploit - Doesn't work on Slimline consoles. Similar to the swap disc, you use a PS1 game to boot a special file on the memory card, from there you can boot backups.
Memor 32 - The newly released Memor 32 can be flashed with a 3rd party BIOS called Memento which gives it similar functionality to a modchip and boots backups directly. Currently Memento is only available for in PAL.
Sony PlayStation 3:
Games have been dumped but there isn't currently a method to play backups. You can play PS1/PS2 backups, but it requires soldering a switch into the PS3 and having a disc to load a TOC from (the disc itself doesn't need to be booted, just inserted whilst on the XMB). This method has been confirmed to work up to firmware 2.0.1.