The MiSTer Neo Geo core just got a long-awaited combo button update

The MiSTer FPGA project has released an update to its Neo Geo core that introduces support for combo buttons, a feature frequently requested by the fighting game community. The update, which was merged into the main branch on February 9 via commit f555111, allows users to map a single physical button on their controller to trigger multiple inputs simultaneously.

This change addresses one of the more persistent friction points when playing SNK's library on modern controllers. While the original Neo Geo AES and CD controllers featured a distinct four-button layout designed for simultaneous presses, translating that to a standard Xbox or PlayStation gamepad often results in awkward thumb gymnastics.

Solving the input problem

Anyone who has played Samurai Shodown or The King of Fighters knows that SNK loved multi-button inputs. Performing a strong slash often requires pressing A and B together. Activating a special mode might require B and C, or even A, B, and C simultaneously. On an arcade stick with the buttons laid out in a row, this is natural. On a DualSense controller where the face buttons are arranged in a diamond, pressing the Square and Circle buttons at the exact same time without hitting X or Triangle is an exercise in frustration.

According to the GitHub issue tracker, this feature (Issue #215) has been on the wishlist for some time. The implementation allows users to define specific combinations within the core's menu. For example, a player could map the right shoulder button to trigger "A+B+C" instantly. This is particularly useful for mechanics like the "Rage Explosion" in later Samurai Shodown titles or the tactical shifts in The Last Blade 2.

FPGA accuracy vs. convenience

The MiSTer project uses Field-Programmable Gate Arrays (FPGAs) to simulate original hardware logic rather than relying on software emulation. This usually means strict adherence to the limitations of the original console. However, the platform has increasingly embraced quality-of-life features that exist outside the original hardware's scope, provided they don't interfere with the accuracy of the simulation itself.

Since this combo button logic is handled by the input framework before the signal reaches the "virtual" Neo Geo, it adds zero latency to the gameplay. This is a significant advantage over software-based macro solutions on PC, which can sometimes introduce a frame of delay or misinterpret inputs during frantic gameplay sequences.

A massive library of fighters

The Neo Geo MVS (arcade) and AES (home console) hardware hosted some of the most technically demanding 2D games of the 1990s. The system launched in 1990 and was supported by SNK until 2004, a lifespan that is practically unheard of in the console market. Because the library is so heavily weighted toward fighting games, input precision is more critical here than perhaps any other core on the MiSTer.

For preservationists and players, this update bridges the gap between authentic hardware behavior and modern accessibility. Original Neo Geo AES controllers are expensive and prone to cracking, and finding a modern arcade stick with the correct curved button layout is difficult. By allowing standard controllers to handle multi-button presses reliably, the core becomes much more playable for someone just looking to play a few rounds of Garou: Mark of the Wolves without investing in specialized hardware.