Altirra 2.6 Test 31 is released. Altirra is an Atari 8 bit Emulator on the Windows/DOS platform. Altirra emulates several models of the 8-bit Atari computers. This includes the the 800, 800XL, and 130XE versions. It has a lot of options, and compatibility is decent especially given the emulator's early stages. It also supports some copy protected games properly in emulation.

Altirra 2.6 Test 31 Changelog:
- Problem: The 64 bit version of Altirra wont run on Win XP 64 Bit Pro, it gives a message "not a valid 32 bit application". Most other 64Bit Programs will run on the same Xp 64 Bit, But som other programs have had the same error. On Win 8.1 the 64 bit version of Altirra Runs, The Pc with XP 64 bit i use for older games, Emulators etc...
- Answer: XP64 for old games? The mutt halfway between XP and Windows Server 2003 that has terrible driver support and still can't run 16-bit applications? Seriously? Why aren't you running XP32? The "not a valid 32 bit application" happens when the application is built for Vista or above.

Download: Altirra 2.6 Test 31
Source: Here