DREAMNEOCD vs NeoCD/SDLx Unleashed

DREAMNEOCD is a Sega Dreamcast emulator for Neo Geo CD games, including selfboot games. It can also be used through DreamShell with an SD card, without CDDA. The project was ported to Dreamcast in 2004 and its maker describes it as the first working Neo Geo CD emulator for the console. It is based on Foster's NeoCD/SDL; the README credits libSDL, using its sound component. To run, it needs a 512 KB system BIOS from an original Neo Geo CD console, named neocd.bin. The README warns that a smaller BIOS will not work with version 1.0 onward, and the repository cautions that the BIOS is copyrighted and users are not entitled to a copy unless they own an original Neo Geo CD console. The program is free, but the maker prohibits selling it and limits source-code and technical-knowledge reuse to noncommercial purposes. The repository lists a GPL-2.0 license. It does not support AES or MVS emulation, related SNK arcade games, netplay, or save states.

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.