Buying a Neo Geo AES — A Practical Guide

In 1990, the Japanese game company SNK released its Neo Geo in two forms. The MVS went into arcades. The AES went into homes. You can still buy both secondhand today, so the first thing to decide is which one you want.

The MVS (Multi Video System) was built for the arcade operator. One cabinet could hold more than one game cartridge. The operator could pull one game out and slide another one in, without buying a whole new machine.

The AES (Advanced Entertainment System) was built for the player who wanted the same arcade games at home. A player could save a game on a memory card at the arcade, take the card home, and carry on playing on the AES. The card worked in both because the hardware inside was the same.

The cartridges are not the same. An MVS cartridge has a different shape and a different connector, so it will not go into an AES on its own. With an MVS-to-AES converter, it will.

MVS cartridges usually sell for much less than the AES cartridge of the same game. Buyers who want the home box, the label art, and the manual pay more for the AES version. Buyers who only want to play the games usually buy MVS cartridges and a converter.

The Neo Geo AES has regional variants (Japan and international / English) but is notably more region-tolerant than most consoles of its era. Many AES cartridges contain both Japanese and English text and will display the language set by the console's BIOS chip (Japanese on a Japanese AES, English on an export AES). The Japanese and international versions of most games are functionally identical; some late-era games have minor content differences. On the MVS arcade board, the operator sets region and language through the board's settings; the AES has no switch for this. Collectors who prefer the Japanese text of the original releases should note that importing a Japanese AES requires a step-down converter for European 220–240V outlets; on North American 120V outlets it is often run without one.

Power supply: the Japanese AES is designed for 100V AC (Japan's domestic voltage). Most AES units use an internal transformer, and many collectors report running Japanese hardware on 110–120V (North American outlets) without issue — the 10% overvoltage is generally tolerated by the hardware. For 220–240V countries (Europe, Australia, most of Asia outside Japan), a step-down converter is required. Do not connect a Japanese 100V console directly to a 220V outlet.

The international (English) AES is electrically identical to the Japanese version but is designed for 110V or the relevant regional standard at point of sale. Verify the input voltage printed on the back of any unit you purchase.

AES cartridges are large — roughly the size of a VHS cassette — because they house the same ROM boards as MVS arcade cartridges. The late-era title Garou: Mark of the Wolves (1999) holds 688 megabits of ROM data. That capacity is what gave Neo Geo games their visual quality: near-lossless transfers of arcade artwork that contemporaries on PlayStation and Saturn had to compress to fit.

New-in-box AES cartridges from the late 1990s are now genuine collectibles. The prices they command reflect both rarity and the cultural weight of what those games represented — the finest 2D fighting games made, on hardware that ran them exactly as the designers intended. If that is what you are buying, the price is what it is.

If you want to play the games rather than collect the artifacts, MVS cartridges with an adapter are the rational choice. The experience is identical. The price is not.