Integrates a next-generation ICMS to ensure stability during loading and gameplay.
The first generations of Wii drive controllers - known as DMS, identical to D2A, and D2B all had a serial port interface that could be used to inject code, making it possible for backup discs to load (and enable other funky stuff as well).
Albeit easy to install, modchips that uses the serial port have some disadvantages. Due to the way they interact with the drive controller it is possible for the Wii hardware to detect them (they modify RAM, for example).
This way of modifying the Wii does not work with the D2C controller, because the serial port can no longer be used to inject or modify code.
D2Ckey uses a new approach we call the Intelligent Code Modifying System (ICMS). Instead of just uploading some code and then doze off, ICMS constantly monitors data on address and data buses, patching it if necessary. This has several advantages:
- It is virtually undetectable by the Wii hardware
- Improved reading of recordable recordable media
- Backup disc loading will emulate original game disc loading closer
By interfacing more of the circuitry of the drive controller D2Ckey has a better understanding of what is going on inside. Stability and compability have been the main design objectives.
A good example of the dangers with oversimplified chips are the 4-wire PIC12C508-based PS1 modchips that where very popular around 1997. First, Microchip, the manufacturer of PIC chips, made some changes in the manufacturing process, affecting the in-system clock. This was technically not a manufacturing flaw, as the fault was still within the tolerance specified in the datasheet, but the chips stopped working. If the 5th wire, a clock signal from PS1, had not been stripped (the 5-wire modchips still using the PS1 clock did not have any problems) then there would not have been any problems. Shortly after games appeared that detected active modchips - once again, a few extra wires would have enabled the chip to know when (and when not to) send data.

features
Access control LEDs
LED 1: disc access indicator.
LED 2: data patching indicator
Flashes smoothly during disc insertion and detection
Lit when backup is detected (after disclogin)
Off when original is detected
DVD media compability
DVD+-R
DVD+-RW
Dual-layer DVD (movies and GCOS)
Game disc support
Direct boot of Wii original and backup games from the same region
Direct boot of Gamecube original and backup games from the same region
Direct boot of different NTSC region Wii and GC games on USA and JAP consoles
Partial region free support on Wii and GC original and backup games with different videomode (ie PAL<->USA, JAPAN)
Improved readsettings for recordable media
Supports running GC games at Wii diskspeed
GC Audiostreaming Fix
Supports full-size DVD and DVD9 discs for GC homebrew
Supports GC multigame discs
Supports Wii and GC multidisc games
True stealth mode
Does not modify RAM, making it virtually undetectable for the Wii
Full command set emulation