An NES, One Transistor at a Time

MetalNES, created by Ian Addisson, is a transistor-level simulation of the original NES-001 hardware.

“Transistor level NES-001 simulation.”

A conventional emulator recreates what the console’s processor and graphics hardware do. MetalNES goes much deeper by simulating the underlying transistor networks inside the NES chips, along with supporting components from the main board.

The project builds on the reverse-engineering work behind Visual2C02 and Visual2A03, which mapped the internals of the NES graphics and processor chips. MetalNES adds support chips, voltage ladders for composite video, and audio output to model more of the complete machine rather than only its software-visible behavior.

That makes it less like pretending to be an NES and more like rebuilding one virtually from its electronic components.

It currently builds only on macOS, lacks memory-management-unit support, and still needs substantial optimization. This is clearly an engineering and preservation project rather than the emulator someone would choose simply to play games.

I love projects like this because they preserve more than the games. They preserve an understanding of how the original hardware actually worked, down to the electrical behavior that produced its graphics and sound.

Explore MetalNES on GitHub.