DREAMNEOCD vs NeoCD/PS2

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/PS2 is a free, open-source NeoGeo CD emulator for the Sony PlayStation 2. It is a port of NeoCD/SDL, adapted to replace SDL components with PS2-native libraries using PS2SDK. Games load directly from the CD-ROM. Video offers PAL/NTSC auto-detection and selection, while the in-game menu includes filtering, fullscreen video, and frameskip controls. The emulator supports two controllers, stereo sound emulation, and CDDA playback. NeoGeo CD memory card support uses 45 KB on a PS2 memory card. ZIP support is limited to the BIOS, and the NeoGeo CD BIOS is not included; users must find it or dump it from their own system. The releases page lists version 0.6c with CDDA fixes, including an auto-loop feature. Listed issues include sound problems when the frame rate is below full speed, timing issues, graphics glitches in some games, and needing to reset the PS2 to exit the BIOS. The project is distributed under GNU General Public License version 2 and says use is at the user's own risk; the README says it should only be used with games the user legally owns.