April 21, 2024

Inside the Super Nintendo cartridges

One of the remarkable characteristics of the Super Nintendo was the ability for game cartridges (cart) to pack more than instructions and assets into ROM chips. If we open and look at the PCBs, we can find inside things like the CIC copy protection chip, SRAM, and even "enhancement processors".

CIC

The copy-protection mechanism of the SNES is something I already dig into in my 10NES article. It works by having two chips talking in lockstep. One chip is in the console, the other in the cart. If the console CIC sees something it does not like, it resets every processor.

Not every SNES cart has a CIC. Unsanctioned games such as "Super 3D Noah's Ark" don't have one. To play the game, one needs to first insert the game in the console and then plug an official cartridge on top. The CIC bus lines are forwarded from Noah's towards the official game's CIC!

ROM: instructions & assets

I was unable to find a list of all SNES games with their ROM size.…