There are two main types of video encoding in the world – NTSC and PAL. They had their reasons for this… with only one of which that actually benefited the consumer. They were used by Nintendo to prevent you from using a game from one region in the hardware from a different region. CIC Region Lockout ChipĮvery SNES game comes with one of these region lockout chips. For my custom boards, I use 22 uF electrolytic capacitors and 0.1 uF ceramic capacitors.

If you don’t have these capacitors, the board will still probably work ok, but it’s good electrical engineering practice to include them. These are called decoupling capacitors, and are used to filter out any stray noisy signals that may be propagating through the VCC line that could disturb the chips and circuitry on the board. There should be at least one for each major chip on the board, like the ROM, RAM, and CIC. Similarly, there are usually multiple small ceramic capacitors scattered across the board. There’s one large bulk electrolytic capacitor (looks like a metal can) that’s used to keep the VCC rail powered on and steady, so that varying voltages supplied from the SNES don’t interrupt the operation of the game, and to help maintain power during any voltage dropouts or similar events.

On every SNES board you’ll notice a handful of capacitors. Let’s start the analysis with an overview of the components on the board and how power is applied. It might have some use in some niche areas, probably with some extra enhancement chips on the board, but for the purposes of this post we will be ignoring it. CART: Low when accessing ROM data (only goes low during certain addresses, based on the memory map)Īs far as I have seen, the /IRQ pin isn’t really used for much on the cartridge. Thanks to neviksti for the convenient pinout. If you look closely, you’ll see some of the pins called out in green above the gold teeth. Since we’re ignoring 8 pins on either side of the 46-pin part, the numbering is going to be offset by a bit. We’ll be looking at only the 46-pin variation. There are two major variations of the connector – one that has just a large 46-pin section, and another variation that additionally has two sections of 8 more pins on each side of the main 46-pin connector (for a total of 62 pins). Let’s start out our analysis at the cartridge connector – the exposed teeth-looking pads at the bottom of the board that goes into your SNES. There are also various capacitors and possibly resistors and diodes for games that have a battery. And if your game saves, then it’ll also have a mapper, battery, and SRAM. (Note that you can still make these games, you’ll just need to use a donor cartridge that already has one of these chips on it.) The “normal” chips include one or more ROM chips and a CIC region lockout chip. The popular example that you probably already know about is the Super FX chip, used in games like Star Fox to generate better 3D graphics. The other types are “enhancement chips” – usually proprietary graphics-boosting chips. For the purpose of this post, since we don’t have an easy way of reproducing these chips (and I lack the knowledge to sufficiently explain their functions), we’re only going to focus on designs of cartridges that use “Normal” chips. If you check out my big list of SNES games you’ll see the games sorted by these different categories. As noted in the main SNES reproduction guide, there are six major categories that set apart different boards – bank type, ROM size, SRAM size, extra chips, speed, and the video type or region. SNES cartridges come in a few different variants, distinct in a few major ways.

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