ClownMDEmu vs Mega-Pi

ClownMDEmu is a free emulator for the Sega Mega Drive, also known as the Sega Genesis. Its self-contained core is provided as a library, with a browser version available to try online. The maker also offers a standalone frontend with debugging menus and a libretro frontend for compatible hosts such as RetroArch and clownlibretro. The core can be built with CMake, but Git submodules must be initialized before compiling. Its design targets C89, integer-only logic, and avoids dynamic memory and global state. Emulator state is stored in a relocatable structure without pointers, supporting save states and the possibility of multiple instances. Audio is output separately for FM and PSG at native sample rates; video is provided one scanline at a time in indexed format. The maker describes a balance between correctness and performance, and notes that some standard Mega Drive features remain unemulated, including areas of 68k exceptions and VDP rendering. ClownMDEmu is free software under AGPLv3 or any later version.

Mega-Pi is a free, bare-metal Sega Mega Drive/Genesis emulator for Raspberry Pi hardware. It targets Raspberry Pi 3 and 4 and runs without an operating system such as Linux, which the project associates with near-instant boot and very low input latency. The emulator uses the Picodrive core and Circle bare-metal C++ framework, assigning orchestration, video, audio, and input work across four ARM cores. It scans .bin, .md, and .gen Genesis or Mega Drive files, plus Sega CD/Mega CD .cue files with .bin tracks and compressed .chd files. Sega CD emulation includes the Sub-CPU, PCM audio, CD audio, and rotation/scaling graphics hardware. Video uses 2× integer nearest-neighbor scaling to 640×480, with 44.1 kHz stereo through the Pi PWM sound engine. USB gamepads and keyboards are supported, and save states reside on the SD card. Running it requires a FAT32 card, boot files, a kernel image, game files, and USB input devices; Sega CD also needs regional BIOS files.