Which Flash Cartridge Should You Choose for Game Boy?

GB Cartridges

The Game Boy console family includes four models:

1. Game Boy;

2. Game Boy Pocket;

3. Game Boy Light;

4. Game Boy Color.

There’s one nuance with the Game Boy Color: officially it’s already a separate console. But for flash cartridges, the difference is minimal — the classic Game Boy and the Game Boy Color use the same cartridge ecosystem.

And those same cartridges also work on the Game Boy Advance (in backward compatibility mode).

But while a flash cartridge may look “universal” from the outside, internally it can behave very differently — and that affects compatibility.

The original Game Boy can directly address only 32 KB of game data — which is tiny. Many games are tens of times larger. To make that possible, cartridges use an extra controller chip that switches memory banks.

Think of it like a railway switch leading into a single track. To get the right train onto the track, you flip the switch. In a Game Boy cartridge, that “switch” is the MBC — Memory Bank Controller.

Left: Tetris. Right: Super Mario Land 2.

Notice how much simpler the Tetris board is compared to Super Mario Land 2. The Mario cart has two extra chips: one for saves and an MBC1 controller. And yes — Tetris is an original cartridge; official boards sometimes use a “black blob” chip.

There are many controller types: MBC1–MBC7 (including less common MBC4 and MBC6), MMM01, HuC-1, and others.

They exist for a reason. For example, MBC3 adds real-time clock support, and MBC5 supports larger ROM sizes and works correctly with the Game Boy Color’s double-speed mode. In short, newer MBCs expanded what the system could do.

That’s why any serious flash cartridge has to emulate most of the common MBC types. “Most” — because there’s no point emulating special cartridges like the Game Boy Camera: the hardware simply isn’t there.

What does this mean in practice?

It means the flash cartridge landscape is more complicated than it looks. Older models may fail on some edge cases. Some modern “single-game” carts only cover one MBC type. And even universal solutions can have their own quirks with certain consoles or accessories.

So let’s go in order: old cartridges, then modern single-game options, and finally the universal ones.

Old Flash Cartridges

The big problem is that the flash cartridge boom happened in the Game Boy Advance era. By then, the industry had moved on, and Game Boy / Game Boy Color were mostly an afterthought.

For many years, that meant your only options were older devices — for example, products by Bung and similar companies, plus a few official Nintendo initiatives.

The main downside of these devices is convenience — or rather, the lack of it. A classic example is the Doctor GB Card 64M. It still works well and supports the main MBC types of its time.

But try rewriting it today… you’ll need an old PC with an LPT port, a DB25 male-to-male cable wired pin-to-pin, a dedicated writer, and a separate power supply for the writer (or six AA batteries).

And today, each of those items is hard to find on its own. Even getting the right LPT cable can be a quest: many modern “printer LPT” cables don’t have all 25 pins connected.

And that’s before you even start hunting for the cartridges themselves. If you’re lucky, something appears on eBay — but most of the time, they’re simply not available.

Prices can also be wild. Sometimes it’s easier to buy a modern console than an old Game Boy flash cartridge setup. In short: these options make sense mainly for collectors.

So for actual gaming, it’s better to look at modern solutions — ones you can buy and use without a museum-grade toolkit.

New Flash Cartridges

The “writer + rewritable cartridge” idea is still alive. Today you can easily find plenty of these kits. For example, FunnyPlaying sells a writer and a line of cartridges designed for it.

And it’s not the only one. insideGadgets, ChisBread, and various Chinese brands sell similar setups: a programmer plus cartridges with specific MBC types.

You can find many of them on AliExpress — including FunnyPlaying products.

What’s the advantage? It’s perfect for a specific game. For example, if you want Pokémon with proper RTC support, the simplest and most reliable approach can be a programmer plus an MBC3 cartridge.

But the downsides are built in:

1. If you have an MBC3 cartridge, you won’t run an MBC5 game — compatibility is tied to the cartridge type;

2. One cartridge = one game.

At first glance that sounds pointless — universal flash cartridges exist, after all.

But there’s a real use case: if you play on FPGA-based hardware (Analogue Pocket, FPGBC, etc.) and you mostly care about one specific title, a dedicated cartridge can be more predictable. Universal solutions aren’t always perfect in every scenario. For example, the Everdrive GB X7 isn’t flawless with Super Game Boy, and the EZ-Flash Junior may boot only on the second or third try on some setups.

Universal Flash Cartridges

Now to the “universal” flash cartridges for Game Boy. Think of them as all-in-one devices: you put ROMs on a memory card, and the cartridge handles the rest.

1. Everdrive GB clones (revision 1)

Around 2014, Krikzz released the first modern Everdrive GB (revision 1). It was a turning point: Game Boy got a flash cartridge that worked like many GBA solutions — run games from a memory card.

Chinese manufacturers quickly copied the design and started selling their own clones.

Overall, the clones are quite usable — with the same strengths and the same typical issues as the original concept.

You can buy them on AliExpress:

Typical issues:

1. Slow switching to a new game. When you select a ROM, the cartridge erases NOR memory, writes the game, and only then launches it. If you keep playing the same game, it’s instant — but switching titles takes time.

2. On some clones, the A and B buttons are swapped. On original Everdrive this can be fixed in settings; on clones it depends on the firmware.

3. The extra menu button behavior varies: on some models it simply reboots, on others it returns to the ROM menu.

4. Some clones use FRAM instead of SRAM. That means no battery and often better behavior on FPGA-based consoles.

The problem is that points 2 and 3 depend on the exact clone revision. Some black “GB Pro” carts behave fine, others don’t. And while the cheapest clones can be very inexpensive, the better “GB Extreme” variants often cost about as much as an EZ-Flash Junior — which makes the choice less obvious.

2. EZ-Flash Junior

After the Nintendo Switch era reignited interest in retro, EZ-Flash entered the Game Boy market with their own cartridge.

On paper it looked close to perfect: fast loading, a menu exit button, support for common MBC types, and RTC.

But then the trade-offs start. The cartridge never felt fully finished: updates stopped, and some bugs were never addressed.

This model is mainly interesting because of RTC. There aren’t many alternatives for games that need a real-time clock. However, stable RTC operation is commonly associated with firmware 1.05e, which was removed from the official site because updating can brick some units. The developer recommends using a high-quality, fast memory card when flashing.

There’s also a battery story. Many users report the Junior’s battery can die in a month or two — and then RTC stops working. One common explanation is the switch from classic SRAM chips to pseudo-SRAM (pSRAM). pSRAM needs constant refresh, so it draws power even when idle, which drains the battery faster.

A dead battery becomes a practical issue: saves first go to pSRAM and then get copied to the memory card on the next boot. If the battery is dead, powering off can wipe that temporary save — so after each session you may need to exit to the menu and wait for the save to be written.

So the picture is mixed. On one hand, EZ-Flash Junior is one of the cheapest RTC-capable options. On the other hand, you may end up swapping batteries, dealing with firmware limitations, and working around its quirks.

If you get lucky — a good hardware revision, the right firmware, and no update drama — you can end up with an almost ideal Game Boy flash cartridge. “Almost” because Everdrive GB X7 offers the same core features plus one killer bonus: instant saves.

3. Everdrive GB — the X series

After the first Everdrive GB, Krikzz refreshed the lineup. The X series includes three models (from entry to top):

1. Everdrive GB X3;

2. Everdrive GB X5;

3. Everdrive GB X7.

There’s a practical caveat: depending on where you live, buying directly can be difficult, so you often end up using resellers — which raises the final price.

For example, an Everdrive GB X5 (feature-wise, behind the early EZ-Flash Junior revisions) can cost around $90 for the cartridge alone. Add reseller markup and shipping, and it can easily approach the price of a full console.

At that point, it makes sense to consider the X7 right away. The Everdrive GB X7 is, essentially, the best flash cartridge for Game Boy today.

With the X7 you get fast loading, RTC support, a proper in-game menu with an exit back to the ROM list, instant saves, and very strong compatibility.

For example, advanced Super Game Boy features (even if not 100%) are handled best by Everdrive cartridges, while the EZ-Flash Junior doesn’t cover that area as well.

The downside is simple: price and availability. Depending on the country and reseller, the final cost can be high once you include shipping.

Epilogue

So, what do we end up with?

If you just want to play Game Boy games, the Everdrive GB Extreme is a solid, affordable clone that’s easy to buy and convenient to use.

If you need a budget cartridge with RTC support, the choice often comes down to the EZ-Flash Junior. Just keep in mind what comes with it: firmware quirks, battery issues, and a bit of “unfinished project” feeling. For specific RTC-heavy games, a FunnyPlaying-style MBC3 solution can be a more predictable route.

And if you’re really into Game Boy / Game Boy Color, it’s usually smarter to save up once and get the Everdrive GB X7. It’s the strongest all-around option — and it’s unlikely anything clearly better (and cheaper) will show up soon.

I don’t recommend retro-era solutions for normal use. There are too many practical hurdles — from day-to-day inconvenience to the need for old hardware just to write games.