FB Alpha 2012 CPS-2 in RetroArch: Source-Based Setup Guide

FB Alpha 2012 CPS-2 is a RetroArch emulator core aimed at CPS-2 arcade games. It is based on a snapshot of the Final Burn Alpha codebase from roughly 2012 and is compatible with FB Alpha v0.2.97.28 ROM sets. The documentation presents it as a narrow-purpose variant that exists for RAM-constrained platforms, and notes that most users should use up-to-date FBNeo instead.

What this core is and who it is for

• Core variant scope: CPS-2 games only.
• Intended use: RAM-constrained platforms, such as certain console or embedded platforms, that cannot load the full core together with large games.
• Compatibility: FB Alpha v0.2.97.28 ROM sets.
• Suggested default for most users: up-to-date FBNeo.

Core details

• Library name: FB Alpha 2012 CPS-2
• Author: Team FB Alpha
• License: Non-commercial

Content format

Content loaded by the FB Alpha 2012 CPS-2 core uses the .zip file extension. The documentation does not describe how to obtain game content, and this guide does not provide or link to game downloads.

Frontend features the core respects

• States
• Rewind
• Core Options

Core options and defaults

• CPU Speed (%) — default 100; available values 110, 120, 130, 140, 150, 160, 170, 180, 190, 200. Enables overclocking of the emulated CPU; can reduce slowdown but may cause glitches.
• High scores — default disabled; can be enabled. Saves high scores in supported games; requires a hiscore.dat file placed in your system/fbalpha2012/ folder.
• Controls — default Gamepad; can be set to Arcade. Sets the default controller mapping.
• Core-Provided Aspect Ratio — default DAR; can be set to PAR. Applies only when RetroArch's aspect ratio is set to 'Core provided' in the Video settings.
• Rotate Vertically Aligned Games (Restart Required) — default enabled; can be disabled. Automatically rotates the display for vertically aligned games; when disabled, D-Pad input is rotated to match on-screen directions.
• Audio Filter — default disabled; can be enabled. Enables a low pass audio filter intended to soften the harsh sound of some arcade games.
• Audio Filter Level (%) — default 60; range 5 to 95 in steps of 5. Sets the cut-off frequency of the low pass audio filter; a higher value increases the perceived strength of the filter because a wider range of the high frequency spectrum is attenuated.
• Frameskip — default disabled; can be set to Auto or Manual. Skips frames to avoid audio buffer under-run (crackling); improves performance at the expense of visual smoothness. Auto skips frames when advised by the frontend; Manual uses the Frameskip Threshold (%) setting.
• Frameskip Threshold (%) — default 33; range 15 to 60 in steps of 3. When Frameskip is set to Manual, sets the audio buffer occupancy threshold (percentage) below which frames are skipped; higher values reduce the risk of crackling by dropping frames more frequently.

How to approach setup

• Confirm the target platform is one of the RAM-constrained platforms the core was made for; on other platforms the documentation directs most users to up-to-date FBNeo.
• Install the FB Alpha 2012 CPS-2 core in RetroArch. The documentation lists the library name as 'FB Alpha 2012 CPS-2' and links the core repository for reference.
• Provide content in .zip format matching FB Alpha v0.2.97.28 ROM sets.
• Open the core options menu in RetroArch and set the options you need. Defaults are: CPU Speed (%) 100, High scores disabled, Controls Gamepad, Core-Provided Aspect Ratio DAR, Rotate Vertically Aligned Games enabled, Audio Filter disabled, Audio Filter Level (%) 60, Frameskip disabled, Frameskip Threshold (%) 33.
• If you enable High scores, place hiscore.dat in your system/fbalpha2012/ folder first.
• If you want the core-provided aspect ratio to take effect, set RetroArch's aspect ratio to 'Core provided' in the Video settings.
• If you change Rotate Vertically Aligned Games, note that the documentation marks a restart as required.

Recovery notes

• Core options can be returned to their documented defaults: CPU Speed (%) 100, High scores disabled, Controls Gamepad, Core-Provided Aspect Ratio DAR, Rotate Vertically Aligned Games enabled (restart required), Audio Filter disabled, Audio Filter Level (%) 60, Frameskip disabled, Frameskip Threshold (%) 33.
• Overclocking the emulated CPU may cause glitches, so lowering CPU Speed (%) back toward 100 is the documented starting point if problems appear.
• The documentation does not describe troubleshooting outcomes beyond these option-level behaviors, so no specific fixes are asserted here.

Official links

The documentation lists the FB Alpha 2012 CPS-2 repository and its issue tracker as external links. Both are hosted on GitHub and point to the libretro fbalpha2012_cps2 project.