How big are retro cartridges, how much data do they hold, and what chips are inside? NES, SNES, Game Boy, and GBA—physical size, ROM capacity, and enhancement chips explained.

Retro Cartridge Size, Storage & Chipsets: A Collector's Technical Guide

If you collect retro games, you've probably wondered: How much data is actually on that cartridge? Why do some SNES games have a second chip visible through the case? What's the difference between a tiny Game Boy cart and a chunky NES one—besides the obvious?

Understanding physical size, storage capacity, and chipsets helps you appreciate what you're holding, spot fakes, and see why certain games were technical milestones. Here's a practical guide across the systems that matter most to retro collectors: NES, SNES/Super Famicom, Game Boy, and Game Boy Advance.

Why This Stuff Matters

Cartridges aren't just plastic and a label. They're physical containers for ROM chips (and sometimes extra processors). The shell size, the ROM capacity, and the presence of enhancement chips all reflect the era and the ambitions of each game. Bigger ROMs meant more levels, more text, more graphics. Special chips let developers do things the base console couldn't—3D, faster math, better compression. For collectors, this knowledge helps with authentication, display, and simply knowing what makes your copy of Star Fox or Kirby Super Star different from a standard SNES game.

Physical Cartridge Size: Form Factors by System

NES (Nintendo Entertainment System)

Form factor: The classic "toaster" style. NES cartridges are large and rectangular—roughly 13 cm wide by 12 cm tall and about 2 cm thick. The front label is large (about 55 × 97 mm), and the cartridge uses a 72-pin edge connector that slides into the front-loading deck. They're heavy, durable, and unmistakable. Famicom carts (Japan) are smaller and top-loading, with a different shape and 60-pin connector.

SNES / Super Famicom

Form factor: Rounded, softer shape than the NES. North American SNES "Game Paks" have the gray/purple rounded front and are roughly 12 cm wide by 11 cm tall, with a 62-pin edge connector. Super Famicom (Japan) carts are slightly different in shape and color (gray with colored stripe) but similar in size. The label area is about 82.5 × 44 mm. These are the carts most SNES collectors are familiar with—the ones that fill the shelves of a 725-set run.

Game Boy / Game Boy Color

Form factor: Small and vertical. Original Game Boy cartridges are about 6 cm tall by 5.5 cm wide and 3 mm thick—compact enough to fit in a pocket. They use a 32-pin edge connector at the bottom. Game Boy Color games use the same physical form factor; the system detects the game type. Label area is around 42 × 37 mm. These are among the smallest mass-market game carts ever made.

Game Boy Advance

Form factor: Even smaller and horizontal. GBA cartridges are roughly 3.5 cm wide by 4 cm long and about 3 mm thick—small enough to lose in a couch cushion. They use a 32-pin connector and are often clear or semi-transparent so you can see the PCB inside. The GBA form factor is one of the most compact commercial cartridge designs.

Quick Comparison

System	Relative size	Connector
NES	Large, rectangular	72-pin
SNES / SFC	Medium, rounded	62-pin
Game Boy / GBC	Small, vertical	32-pin
GBA	Smallest, horizontal	32-pin

Storage Size: How Much Data Fits in the Cartridge

Storage is measured in bits (Mb or Mbit) or bytes (KB, MB). Marketing often used megabits; when we say "24-megabit game," that's 24 Mb = 3 MB of ROM.

NES

Typical range: 40 KB to 384 KB (smallest games to larger RPGs).
With mappers: Up to 512 KB PRG ROM (program/code) and 256 KB CHR ROM (graphics) depending on the mapper chip. The NES CPU could only address 32 KB of program ROM at once, so mapper chips (see below) used bank-switching to access more.
Largest official titles: Games like Kirby's Adventure and Final Fantasy III pushed toward the high end of what NES mappers allowed.

SNES / Super Famicom

Standard LoROM / HiROM: Up to 4 MB (32 Mb) without enhancement chips. Most of the 725 licensed US SNES games fall in the 1–4 MB range.
With enhancement chips: Up to 8 MB (64 Mb) with SA-1 or extended formats (ExLoROM, ExHiROM, S-DD1). Kirby Super Star, Super Mario RPG, and Dragon Quest VI are examples.
Super FX (early): Early Super FX games were limited to 1 MB ROM; the GSU-2 revision allowed larger ROMs for titles like Yoshi's Island and Doom.

Game Boy / Game Boy Color

No MBC: 32 KB fixed (very early/simple games).
With Memory Bank Controllers (MBCs): Up to 8 MB (64 Mb) ROM. Most commercial titles used 256 KB to 1 MB; a few later games (e.g. Pokémon Gold/Silver) used 2 MB or more.
Save RAM: Often 8 KB to 32 KB battery-backed SRAM for save data.

Game Boy Advance

Standard maximum: 32 MB (256 Mb). This was the normal cap for commercial releases.
Typical range: Many GBA games are 8 MB to 32 MB. Smaller titles (e.g. some puzzle games) can be 4 MB or less.
Rare exceptions: A few titles used custom hardware to reach 64 MB; this was uncommon.

Sega Genesis / Mega Drive (Brief)

For context: standard Genesis carts topped out at 4 MB (32 Mb) for most releases; Sonic 3 & Knuckles and similar pushed that. Super Street Fighter II used a special mapper to reach 40 Mb. So SNES and Genesis were in the same ballpark for "big" carts in the 16-bit era.

Chipsets: What’s Inside the Cartridge

Beyond the ROM, many cartridges include mapper or enhancement chips that extend what the console can do.

NES: Mapper Chips (MMC)

The NES could only see a small amount of ROM at once. Mapper chips (Memory Management Controllers) used bank-switching so the game could use more code and graphics than the console’s address space allowed.

MMC1: Very common (e.g. The Legend of Zelda, Metroid). Supports up to 256 KB PRG ROM, 128 KB CHR ROM, and 32 KB RAM. Simple and reliable.
MMC3: Also extremely common (e.g. Super Mario Bros. 3, Kirby's Adventure). Supports up to 512 KB PRG, 256 KB CHR, 8 KB RAM. More flexible for scrolling and effects.
Other mappers: MMC2, MMC4, VRC (Konami), Sunsoft, etc. Each had different limits and features. Unlicensed games sometimes used their own mappers.

No NES cartridge had a "coprocessor" in the SNES sense—just ROM and a mapper.

SNES / Super Famicom: Enhancement Chips

The SNES was designed so cartridges could include coprocessors. These ran inside the cart and did work the main CPU couldn’t.

Super FX (GSU-1 / GSU-2): A RISC coprocessor for 3D and advanced 2D. Used in Star Fox, Vortex, Doom, Stunt Race FX, Yoshi's Island. GSU-2 ran faster and supported larger ROMs. This is why Star Fox and Yoshi's Island feel so different from standard SNES games.
SA-1 (Super Accelerator): A faster CPU (about 10.74 MHz vs. the main 3.58 MHz) with extra RAM and DMA. Used in Super Mario RPG, Kirby Super Star, Mario & Wario, Dragon Quest III (SFC), and others. Enables more sprites, faster logic, and larger ROMs (up to 8 MB).
DSP-1: A digital signal processor for math: 2D/3D coordinate transforms, raster effects. Used in Pilotwings, Super Mario Kart, Street Fighter Alpha 2 (SFC). Very common; over a dozen games use it.
DSP-2, DSP-3, DSP-4: Variants used in specific games (e.g. Dungeon Master, SD Gundam GX).
Cx4 (Capcom): Math coprocessor (Hitachi) for rotation and wireframe. Used in Mega Man X2 and Mega Man X3 for the wireframe bosses and effects.
S-DD1: Used for decompression of graphics. Star Ocean and Tales of Phantasia (Super Famicom) use it to fit huge amounts of art and text.
Other chips: SPC7110 (data decompression), OBC-1 (sprite/object control), etc., in a handful of titles.

Games with enhancement chips often have a second chip visible when you open or backlight the cartridge. Collectors sometimes use this to confirm authenticity (repros may omit or fake the chip).

Game Boy: Memory Bank Controllers (MBC)

Game Boy cartridges don’t have "enhancement" chips like the SNES. They have Memory Bank Controllers (MBCs) that switch ROM (and sometimes RAM) banks so the 8-bit CPU can use more than 32 KB of ROM.

MBC1: Most common. Supports up to 2 MB ROM, 32 KB RAM. Used in Pokémon Red/Blue, Link's Awakening, and many others.
MBC3: Supports up to 2 MB ROM, 32 KB RAM, plus real-time clock (RTC) for Pokémon Gold/Silver/Crystal.
MBC5: Supports up to 8 MB ROM, 128 KB RAM. Used in the largest GB/C titles.
Others: MBC2, MBC6, MBC7, MMM01, etc., for specific games or features (rumble, RTC, etc.).

So "chipsets" on GB mean which MBC and how much ROM/RAM the cart supports.

Game Boy Advance

GBA cartridges are simpler: no Nintendo-branded enhancement chips. The ROM size is set by the mask ROM on the board (up to 32 MB standard). Some carts include SRAM + battery for saves, or Flash/EEPROM for save data. A few late releases used infrared or other hardware, but there’s no equivalent to the SNES’s SA-1 or Super FX.

Why Collectors Care

Authenticity: Knowing which games use which chips (and how many chips are visible) helps spot reproductions. Fake SNES carts often use a single ROM and no enhancement chip; real Kirby Super Star or Super Mario RPG boards have an SA-1.
Rarity and cost: Enhancement-chip games were more expensive to produce. They’re often rarer and command higher prices. Understanding chips explains why certain titles are sought after.
Display and storage: Physical size affects how you store and show a collection. NES carts take more space than GBA; SNES and SFC have different regional shapes. Knowing dimensions helps with shelving and display.
Preservation: ROM size and chip type matter for dumping and archiving. Accurate dumps need the right mapper/chip handling so the game runs correctly in emulators and on flash carts.

Quick Reference Table

System	Typical ROM size	Max ROM (standard)	Key chips / mappers
NES	40 KB – 384 KB	512 KB (with mapper)	MMC1, MMC3, others
SNES	1 MB – 4 MB	4 MB (8 MB with SA-1 etc.)	Super FX, SA-1, DSP-1, Cx4, S-DD1
Game Boy	32 KB – 2 MB	8 MB (MBC5)	MBC1, MBC3, MBC5
GBA	4 MB – 32 MB	32 MB	None (ROM + save)

Your Collection as a Technical Library

Every cartridge on your shelf is a snapshot of what was possible at that time: how much data, what kind of chip, and what form factor. The 725 US SNES games span the full range—from small, no-chip titles to 8 MB SA-1 epics. Tracking your collection and browsing the full SNES library is one way to see that spread. And if you’re into GBA or NES as well, you’re holding decades of cartridge evolution in your hands—from the big gray NES blocks to the tiny GBA cards, from 32 KB to 32 MB, from simple mappers to full coprocessors.

If you want to go deeper, we recommend checking out Nesdev for NES, SNESdev and full chip lists for SNES, and GBATEK for GBA. Your retro cartridge collection isn’t just nostalgia—it’s a physical archive of how game hardware and storage evolved.