Question: what cords are needed for gamecube?
Answer: Locate the audio/video INPUT jacks on the TV. (Audio/video Input jacks are also known as RCA JACKS.)
Place the Yellow (Video) cable into the Video IN on the back of the TV. ... 
Connect the Rectangular (Gray) plug of the Stereo AV Cable into the Analog AV Out port on the back of the Control Deck.