"Well, developers don't get low level info on GameCube. And as far as I know, no such info is out. That's why sound and gfx (the 3d functions) are so hard to emulate/use in homebrew.
The only guys giving out that would be Nintendo research and development. Don't see them sending out docs anytime soon."
Look - I'll "leak" some technical designs right now for you -
http://www.uspto.gov/web/patents/patog/week39/OG/html/US06456290-20020924.html interface for a graphics system - Nintendo
http://www.uspto.gov/web/patents/patog/week48/OG/html/1264-4/US06485369-20021126.html - Video game apparatus outputting image and music and storage medium used therefor - Nintendo
http://www.uspto.gov/web/patents/patog/week29/OG/html/US06421058-20020716.html - Graphics command stream for calling a display object in a graphics system - Nintendo
http://www.uspto.gov/web/patents/patog/week39/OG/html/US06454652-20020924.html - Video game system and method with enhanced three-dimensional character and background control due to environmental conditions - Nintendo
http://aiw2.uspto.gov/.aiw?Docid=20...ageNum=&Rtype=&SectionNum=&idkey=84C87E694543 - Our friend the game cube
There are THOUSANDS of patents and other documents detailing the inner most workings of ALL the nintendo consoles. (and any other console for that matter) Each one usually comes with pages (sometimes hundreds) deatailing EVERYTHING in simple english. Here is but one line from a document with tons of pages explaining how mario 64 works
"If the check at 943 reveals that Mario did not touch a door to the second door then, as shown in FIG. 15B, a check is made to determine whether Mario touched door 1 of the first floor. If Mario hit door 1, then Mario is permitted to enter course 1 by leaping through the course 1 picture, without any goal achievement requirement. "
"The PCHCLK signal is the basic clock signal which may, for example, be a 15.2 MHz signal utilized for clocking communication operations between the coprocessor 200 and the peripheral interface 138. The PCHCMD command is utilized for reading and writing from and to RAM 264 and for reading from boot ROM 262. The peripheral interface 138 in turn provides a PCHRSP response which includes both accessed data and an acknowledgment signal. " Wow that's neat I didn't know that before!
(if you want to see these pages click "full text" on the patents)
All straight from Nintendo to you from the US patent office.
Make no mistake though - by no means are all patents put on the patent web site (that would take far too much time) but you can order them via paper mail from the office its self. A huge number of them are on the web though.