Emulated hardware
Altirra lets you select the Atari model, memory size, operating system and PAL or NTSC video standard. It includes replacement operating systems and BASIC. Hardware configuration affects software compatibility, graphics and sound.
Debugger
The debugger can pause a program, step through instructions and inspect registers and memory. Assembler listings and labels help trace machine code.
Programs, media and save states
Altirra loads XEX programs and disk, cassette and cartridge images. A save state preserves the current session; a BAS file saved from BASIC or an ATR image can also be transferred elsewhere. PAL/NTSC settings and the number of emulated POKEYs matter when comparing graphics and music.