SD Gecko (Wiikey version)
|Type||SD/SDHC/SDXC (Class 2/4/6/10)|
16MB-2TB(up to 128GB tested in Swiss)
The SDGecko is a simple 'straight through' device meaning that it has no components and simply connects the SD card pins to the Gamecube memory card port pins. SD Cards have a SPI mode which is basically what the EXI bus (memory card ports) use which is why this device is so easy.
It is supported in the majority of Gamecube homebrew (emulators, gc-linux, etc). Since the SD Card support is all done in software, SD, SDHC and SDXC Cards are supported natively through libOGC.
Nintendo officially released the SD Gecko (DOL-019) in Japan exclusively for users to save their game in Animal Crossing. After that there were generic 3rd party adapters released, but mainly for homebrew. When the Wii was released as there was no homebrew that was able to utilize the front-sd slot initially, so naturally there was a higher demand for an SD adapter to dump games with. Due to that demand, the Wiikey team released the Wiikey SD Gecko to dump full Wii discs to SD Card via Gamecube mode homebrew using the SD Gecko.
SD Media Launcher
Datel (a.k.a. Code Junkies) also commercially released a SD Gecko device known as "SD Media Launcher". Their reason behind it was to be able to store cheats on the SD card (much like Datels other devices but which did it on the Memory Card). It came with a bootable Gamecube DVD disc which could be used for Region Free, Cheats (from SD card), or to load homebrew executable files (.DOL) from the SD card. It is a popular solution for those who wish to play backups/originals without needing to open up their console.
DoItYourself SD Gecko
You can easily build one yourself, if you have some broken/old EXI-Hardware and an SD-slot/unused MiniSD-Adapter, you just have to connect some pins together, as the EXI bus and SPI bus are similar. You can even add a LED in parallel to the data line, so you can see, when the cube is reading data.
(click to enlarge)
|EXI Pin||SD Pin||/||SD Pin||EXI Pin|
Dont forget to connect EXI pin 1 and 12, if your card not already has it, otherwise the cube won't recognize the device.
It is possible to swap SD pin 3 and 6 or EXI pin 2 and 10 or connect them all together (common ground). It is also possible to use EXI pin 8 instead of pin 4 with SD pin 4.
The data line the LED is attached to, is 3.3V. Choose the right resisitor, if your LED needs one.
(click to enlarge)