- Home
- Atari Emulators
- Altirra
Altirra
What it is
Altirra is a free Windows emulator for 8-bit Atari computers, covering the Atari 400/800, 1200XL, 600/800XL, 130XE, XEGS, and 5200. It provides cycle-exact emulation for documented hardware and models details such as precise DMA timing and undocumented 6502 instructions. Supported image and software formats include ATR, ATX, ATZ, DCM, XFD, PRO, ARC, BAS, ROM, BIN, A52, CAS, and SAP. Altirra supplies reimplemented OS, BASIC, and handler ROMs, while real Atari ROM images can be used for compatibility. Hardware expansion emulation includes memory and cartridge additions, PBI devices, modems, and 65C02/65C816 accelerators. Disk options cover accelerated loading, realistic timing, drive sounds, and drive CPU emulation. Its debugger offers source stepping, breakpoints, watchpoints, execution history, and profiling. Recording tools, a cheat trainer, disk explorer, text copy/paste, save states, and controller remapping are included. It runs on Windows 7 or later with x86/x64 or ARM64 builds.
For and against
For
- Cycle-exact documented hardware emulation
- Supports many Atari image formats
- Includes source-level debugger tools
- Offers save states and controller remapping
- Free under GPL version 2
Against
- Setup is described as involved
- Users need their own Atari software
- Windows RT is not supported
- ARM64 build requires Snapdragon 835 or higher
The verdict
Altirra combines broad Atari system coverage with detailed emulation, debugging, recording, and disk utilities. Its free Windows distribution is most suitable for users comfortable supplying software and configuring an emulator.
Who it suits
Altirra suits Windows users who need an Atari 8-bit emulator, debugger, or both. It is aimed at people prepared for involved setup and who have their own Atari software.
Plans and prices
Altirra
GNU General Public License (GPL), version 2 · Windows 7 or later · x86/x64 or ARM64
Read 3 Oct 2026 · virtualdub.org
On the record
- Accuracy
- It provides cycle-exact emulation of documented hardware features and emulates undocumented behavior such as precise DMA timing and undocumented 6502 instructions.virtualdub.org · read 3 Oct 2026
- Debugger
- The debugger includes source-level stepping, conditional breakpoints and tracepoints, watchpoints, execution history, and profiling.virtualdub.org · read 3 Oct 2026
- Disk drives
- Disk-drive options include accelerated loading, realistic disk timing, drive sounds, and full drive CPU emulation.virtualdub.org · read 3 Oct 2026
- Download architectures
- The site offers x86/x64 and ARM64 binaries; the ARM64 build is for Windows 10 on ARM on Snapdragon 835 or higher.virtualdub.org · read 3 Oct 2026
- Emulated systems
- It emulates the Atari 400/800, 1200XL, 600/800XL, 130XE, XEGS, and 5200 systems.virtualdub.org · read 3 Oct 2026
- Expansion emulation
- It emulates hardware expansions including memory and cartridge expansions, PBI devices, modems, and 65C02/65C816 accelerators.virtualdub.org · read 3 Oct 2026
- File formats
- Supported image and software formats include ATR, ATX, ATZ, DCM, XFD, PRO, ARC, BAS, ROM, BIN, A52, CAS, and SAP.virtualdub.org · read 3 Oct 2026
- License and affiliation
- Altirra is licensed under GPL version 2, and the author states that neither the author nor the software is affiliated with Atari.virtualdub.org · read 3 Oct 2026
- Notable limitation
- The author says Altirra is designed as a system emulator and debugger, and that setup is involved; users need their own Atari software.virtualdub.org · read 3 Oct 2026
- Recording and utilities
- Features include audio and video recording, a cheat trainer, a DOS disk explorer with drag-and-drop, and text mode copy/paste.virtualdub.org · read 3 Oct 2026
- ROMs
- Altirra includes reimplemented OS, BASIC, and handler ROMs, while real Atari ROM images can be used for greater compatibility.virtualdub.org · read 3 Oct 2026
- System requirements
- The listed operating systems are Windows 7, 8, 8.1, 10, 11 or later; Windows RT is not supported.virtualdub.org · read 3 Oct 2026
- What it does
- Altirra is an emulator for 8-bit Atari computers.virtualdub.org · read 3 Oct 2026
