The N64 3X3 is a redesigned N64 circuit 3 inches on each side. About 2 years ago for a fun summer project I mapped out the whole N64 schematic, I made a layout but stopped there from lack of pcb design confidence. With the excitement on my N64 projects recently I revisited the project after realizing the more you trim off the N64, the more relevant a new pcb would be. I looked over the original schematic I made and there was a few things missing and redid the layout.
First I’ll start by giving credit where credit is due, the first N64 3X3 was made by Marshallh however the project had been halted in favor of other things so I decided to pick it up and run with it as far as I can and hopefully we’ll see it into a portable. Also I have to thank him for helping me debug the pcb.
The trickiest part of the layout certainly being the RDRAM routing, I kept the traces straight with ground in between and the termination resistors as close as possible and crossed my fingers.
At the top of the PCB is a 50pin FFC connection for the cartridge and on the right is a 26pin connection for digital video output. I designed it to interface with the ultraVGA/HDMI mod. It uses an FPGA to create high quality video output. There are 2 variations of the stock N64 video circuit which could complicate the PCB and I think most people nowadays are only interested in VGA anyway so that was my choice. Audio output will be only through custom digital audio amplifier too.
This is just the beginning for this project. I’ve confirmed my schematic and asset is correct and working and now I can add more to it to be used in a complete gaming system. My hope is to make some variation of it opensource for anyone who wants to make a compact and neat N64 portable. I enjoyed the most learning deeper into the N64 hardware and mapping out the minimum required components for the circuit which helped tremendously for trimming too.