From GBATek
Pin Name Cable
1 VDD35 N/A GBA Socket GBA Plug Old "8bit" Plug
2 SO Red ___________ _________ ___________
3 SI Orange | 2 4 6 | / 2 4 6 \ | 2 4 6 |
4 SD Brown _1_ 3 5/ _1_ 3 5/ _1__3__5_/