After the success of Gekko, IBM presumably grabbed this design and re-branded it as '750CL' for other manufacturers to use . Then, when Nintendo requested a new CPU to use with their new console, still known as 'Revolution' (hence the RVL prefix on their stock motherboards), IBM and Nintendo agreed to use a 750CL clocked 1.5 times the speed of Gekko. This CPU is known as Broadway and runs at 729 MHz.
After having reviewed Gekko, I'm afraid there aren't many changes found in the new CPU. However, this may be an advantage: GameCube developers were able to start developing their new Wii games right away thanks to all the experience they gained with Gekko. Moreover, the fact that Broadway runs 1.5x the original speed will allow them to push for more features and quality.
What about memory?
This one is an interesting bit, the old GameCube memory layout has been re-arranged and enhanced with the following changes:
- Splash (24 MB of 1T-SRAM) now resides inside the Hollywood SoC (explained later) and it is now called MEM1 .
- ARAM (16 MB of serial SDRAM) is long gone, however...
- There's a new memory chip, MEM2, which includes 64 MB of GDDR3 SDRAM for general purpose.
- This type of memory is based on the traditional DDR2 system but revamped with higher bandwidths (~2 times the original transfer rates) and reduced power consumption, which is ideal for GPUs.
Backwards compatibility
For now, you can think of this console as a superset of the GameCube and as such, compatibility with the previous generation of games is naturally inherited. That being said, in order to make the Wii fully backwards compatible, the old set of external ports were brought to the Wii, these include the GameCube controller and memory card ports. However, there's a new constraint: The new memory map is incompatible with the old one. Thus, a thin 'emulation' layer was implemented in software (more details in the 'I/O' and 'Operating System' section).
Regarding the GameCube accessories using the Serial/Hi-Speed socket, I'm afraid the Wii didn't include these ports, so those accessories can't be used here.
In later years, new revisions of the Wii saw these ports removed, unfortunately.