This was a royal pain to figure out, and I feel the need to write it up somewhere - I did get part off google (the voltages), which I will link below this paragraph, but I also had to rip my console apart to find the pin numbers on the logic board (screw you, nintendo, for those screws).
My source for voltages, to match against pin numbers: http://pinouts.ru/Game/nintendo_power_pinout.shtml
What you need:
An unloved ATX PSU.
Either the brains to find something that can be used to make a plug that will fit (please share what, if you do) or being comfortable with the possibility that your cat walking by could cause an electrical fire (as could breathing on the console, practically), if you just jam the wires into the holes - you'll have 12v right next to a ground, and it should be watched at all times the console is on (alternately, the wires could be soldered onto the logic board, or the backs of the pins). In the long run, I'll probably put a circular (of the type found inside female molex connectors) push connector on each wire, and heatshrink it all the way to slightly past the tip, for safeties sake.
The pinouts are as follows (viewing from the back of the console, right-side-up):
3 2 1
6 5 4
3.3v 3.3v gnd
12v gnd gnd
orange orange black
yellow black black
And to start the PSU, jump the green wire to a black wire. Be VERY careful not to let any of the other wires you're using touch each other, or anything but the pin they're supposed to be connecting to.
My source for the powers does list the amperage for each pin, but just about any ATX PSU should have enough.
If anyone is so grateful that they feel compelled to donate an n64 controller, I'd be much obliged.
PS: don't waste your time or knuckles trying to make a PSU connector fit, it won't, I'd be willing to bet you. I did several things to them and it seems hopeless, they're square and don't fit, and not the kind of plastic that you can fit with heat - it's just frustrating, because it's so close.