Altirra

What it does

Accuracy

It provides cycle-exact emulation of documented hardware features and emulates undocumented behavior such as precise DMA timing and undocumented 6502 instructions.checked 3 Oct 2026

Debugger

The debugger includes source-level stepping, conditional breakpoints and tracepoints, watchpoints, execution history, and profiling.checked 3 Oct 2026

Disk drives

Disk-drive options include accelerated loading, realistic disk timing, drive sounds, and full drive CPU emulation.checked 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.checked 3 Oct 2026

Emulated systems

It emulates the Atari 400/800, 1200XL, 600/800XL, 130XE, XEGS, and 5200 systems.checked 3 Oct 2026

Expansion emulation

It emulates hardware expansions including memory and cartridge expansions, PBI devices, modems, and 65C02/65C816 accelerators.checked 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.checked 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.checked 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.checked 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.checked 3 Oct 2026

ROMs

Altirra includes reimplemented OS, BASIC, and handler ROMs, while real Atari ROM images can be used for greater compatibility.checked 3 Oct 2026

System requirements

The listed operating systems are Windows 7, 8, 8.1, 10, 11 or later; Windows RT is not supported.checked 3 Oct 2026

What it does

Altirra is an emulator for 8-bit Atari computers.checked 3 Oct 2026