Altirra vs Virtual Jaguar

Altirra is a Windows emulator for 8-bit Atari computers, covering the Atari 400/800, 1200XL, 600/800XL, 130XE, XEGS and 5200. It provides cycle-exact handling of documented hardware and models undocumented behavior, including DMA timing and undocumented 6502 instructions. Supported files include ATR, ATX, ATZ, DCM, XFD, PRO, ARC, BAS, ROM, BIN, A52, CAS and SAP. Reimplemented operating-system, BASIC and handler ROMs are included, while real Atari ROM images can be supplied for compatibility. The emulator models memory and cartridge expansions, PBI devices, modems and 65C02/65C816 accelerators. Disk options include accelerated loading, realistic timing, sounds and drive CPU emulation. Its debugger offers source stepping, breakpoints, watchpoints, history and profiling. Recording, a cheat trainer, disk browsing and text copy/paste are also included. Altirra is free under GPL version 2 for Windows 7 or later.

Virtual Jaguar libretro is a free, open-source emulator core for Atari Jaguar cartridges and Jaguar CD media. It is designed to run through a libretro frontend such as RetroArch, not as a standalone emulator. The core emulates the Jaguar’s 68000, GPU, DSP, Object Processor, and Jaguar CD hardware. It accepts cartridge formats including .j64, .jag, .rom, .abs, .cof, .bin, and .prg, plus Jaguar CD CUE, CDI, and CHD images. Console and Jaguar CD BIOS images are embedded, so external BIOS files are not required. Through its frontend, the core supports save states, cheats, rewind, run-ahead, netplay, shaders, controller remapping, and fast-forward. Optional settings include true-color rendering, 2× internal resolution, overclock controls, and adjustable CD read speed. Link-cable emulation supports TCP transport and a multi-peer hub. The project notes that the blitter is not fully cycle-accurate, GPU/DSP pipeline hazards are not modeled, and some titles can run too fast. Listed platforms include Android, iOS, Linux, macOS, web, and Windows.