Genesis Plus GX vs XRoar

Genesis Plus GX is a free, open-source emulator for Sega's 8-bit and 16-bit systems, including SG-1000, Mark-III, Master System, Game Gear, Genesis/Mega Drive, and Sega/Mega CD. It supports backward-compatibility modes and describes its CPU, video, and sound emulation as highly accurate, with cycle-accurate CPU and sound synchronization. The emulator reads raw and interleaved ROMs, as well as CUE+BIN, ISO+WAV, and ISO+OGG CD images. Emulated peripherals include 2-, 3-, and 6-button pads, multitaps, the Sega Mouse, and light guns; supported cartridge hardware includes SVP DSP, EEPROMs, Game Genie, Action Replay, and Lock-On. Standalone builds are available for GameCube and Wii, and the project lists access through frontends such as RetroArch, BizHawk, and OpenEmu. It describes compatibility with released software for its supported systems, while noting that it cannot test every game from start to finish. Some Master System games depend on particular hardware or VDP modes. The multi-platform core source is under a non-commercial license.

XRoar is a free emulator for Dragon, Tandy Colour Computer, Tandy MC-10, and related 8-bit systems. Supported machines include Dragon 32/64/200-E, Tandy CoCo 1/2/3, MC-10, and Matra & Hachette Alice 4K. It runs on Android, Linux, macOS, and Windows, with XRoar Online available in a browser. The emulator reads and writes cassette, floppy disk, and block-device images, and supports machine snapshots. Emulated hardware includes floppy controllers, sound cartridges, Glenside IDE, and several RAM expansions. Video options include PAL or NTSC emulation and composite video simulation, with multiple sound drivers. A GDB remote target supports interactive debugging, though 6803 debugging is not implemented. The Becker port can communicate with pyDriveWire or Drivewire 4. In the browser version, users can fetch cassette, floppy, and hard disk images from the web or upload local files, but its sandbox keeps accessed files temporarily in memory rather than working transparently with local files. Firmware ROM images are required for useful emulation, and floppy write-back is enabled by default. XRoar is GPL version 3 or later software and comes without warranty.