Geolith vs NeoCD/SDLx Unleashed

Geolith is a free emulator for the Neo Geo AES, MVS, CD, and CDZ. It supports commercially released AES, MVS, and CD games, and runs on Linux, macOS, BSD, and Windows. Cartridge systems accept TerraOnion .NEO files; CD systems use .bin/.cue and can optionally use .chd images. BIOS files from a recent MAME set are required, with the needed archives varying by system. Geolith synchronizes its CPUs with the video and sound systems, though video event timing is best effort and cycle-accurate rendering remains a longer-term goal. Settings include system and BIOS mode, region, free play, memory card options, palette, and aspect ratio. Supported inputs range from Neo Geo joysticks to a Mahjong Controller, four-player extension board, V-Liner, and the Irritating Maze trackball. The project was written for The Jolly Good API and can be used in multi-emulator frameworks or standalone binaries. It does not support dedicated JAMMA PCB systems or PAL mode; an early Stakes Winner prototype is also unsupported because required data is missing.

NeoCD/SDLx Unleashed is a free Neo Geo CD emulator for the original Xbox. It runs many original Neo Geo CD games and reads real discs in ISO9660 format. The emulator does not support bin/cue or iso/mp3 images and requires an uncompressed 512 KB system BIOS named neocd.bin; the download page says a BIOS copy is permitted only for owners of an original Neo Geo CD console. It supports one or two players, full CDDA audio, region selection and memory cards. Display modes include 480p and 720p, selected according to dashboard settings. Video filters are AdvanceMame2x, Simple2x, SuperSai2x, SuperEagle and Scanline. Source code is released, and the download is a 448.6 KB ZIP attachment with no Digiex registration required. The page reports miscellaneous sound and timing issues and provides the program without warranty. The listed platform is the original Xbox. AES and MVS emulation, plus other related SNK arcade systems, are not supported.