Atari++ v1.72 is released. The Atari++ Emulator is a Unix based emulator of the Atari eight bit computers, namely the Atari 400 and 800, the Atari 400XL, 800XL and 130XE, and the Atari 5200 game console. The emulator is auto-configurable and will compile on a variety of systems (Linux, Solaris, Irix).

Its emulation features are stunning:
Cycle precise emulation; this includes correct emulation of horizontal kernels and programs that modify chip registers within a horizontal line. In a less technical language, software making use of advanced displaying techniques will be emulated correctly.
Emulation of an advanced 1050 disk drive including single, double and enhanced density. The emulator not only understands .atr and .xfd files, but comes with a mini-boot loader that allows you to boot from binary load files (.exe and .com).
Supports .gz compressed images, and .DCM disk images. No additional tools required to load these disks.
Precise emulation of ANTIC and GTIA graphics, including undocumented scrolling features, undocumented GTIA player/missile priorities and collision detection, and some other less known GTIA features. Color artifacting is also available.
Precise emulaton of POKEY sound, including "Software Speech", high-pass filters and POKEY hardware timer interrupts. An emulation of the console speaker is also included.
Precise emulation of the POKEY SIO (serial transfer) protocol, including the Atari "sound effects" on disk loading and some lesser known influences of serial transfer on the sound subsystem.
Pokey stereo hack ("Gumby") included in the emulation.
Emulates graphics output either thru X11, or the SDL library, including a screen snapshot feature, saving images as PGM, BMP or PNG.
Sound output is either emulated by the Open Sound System (OSS), the ALSA system, the SDL library, or by recording the sound samples into a WAV file in CD quality.
Cylce-precise 6502 emulation, including "extra-instructions" that are not documented in the 6502-manual, and also including all known hardware-bugs of the 6502.
Printer emulation thru standard LPR printer user interface.
Flicker-Fixer option for games that toggle palettes fast for more colors.
Emulation of color artifacts due to PAL color subsampling
Optional de-blocking filter for magnified output
Built-in Os emulation
Joystick, paddle and lightpen emulation by keyboard or mouse, or by standard analogue PC joysticks. A special home-made interface allows the connection of Atari digital joysticks by an additional joystick driver. Hence, you'll be able to play all your old games even with your digital joysticks.
Includes emulation of the Pokey POT reading mechanism.
Saves and loads machine states to save games in the middle of the game play, and allows to resume from that point later on.
Includes emulation of a variety of cartridge types, including 5200 games cartridges and Oss supercarts.
Effective emulation of 800XL/XE and cartridge bank-switching mechanisms.
Emulation of the Atari 850 Interface box by the serial port of the host computer, including a full 850 driver "in ROM".
Interfaces to "Hias'" AtariSIO driver, allowing you to connect real Atari hardware to the PC.
Includes a Dos 2.xx compatible interface to the filing system of the emulator.
Easy to use graphical user front-end for simple setup and configuration, includes saving and loading of (human-readable) configuration files. The user front-end also allows to setup details like the player/missile collision setup to build "game-trainers" on demand.
Includes a built-in monitor allowing experts to debug Atari software easily.
And the best: It is free.

Atari++ v1.72 Changelog:

- The binary file loader automatically generated when inserting a COM or EXE into the disk drive and booting from it is now much shorter and requires a lot less RAM. It requires now, however, an additional ESCape code and hence emulator support. This will now also load binary files that require RAM from 0x800 and up. - This release adds support for ATX files and includes an emulation of the disk drive timing, handling of bad and duplicate sectors and a more precise emulation of the SIO timing. - An additional type of watch point was added: The default watch point now only reacts on memory writes, whereas the new watch point continues to react on reads and writes. - Experimented a lot with the timing of the GTIA Prior writing and found that the currently implemented logic is actually very close to the real system, additional delay cycles make results only worse, not better. Thus, leaving it as it is right now. - The SDL StringGadget now reacts on Ctrl+Backspace and Ctrl+Delete and erases its contents on this keyboard command. - Added emulation for "stuck" Player/Missile shift registers when switching from 4x or 2x expansion to the size register "2" value, which is almost, but not quite 1x expansion. - The built-in Os blocks NMIs now early in the reset cycle and by that tries to work around bad display lists left over by buggy programs. - Minor modification in the built-in FMS (Dos 2.++): CONFIG.SYS can now change the position of the FMS buffers by poking into DiskBufferBase $710,$711 and relocate them. - Minor modification of the short VBI: GPrior, ColBK and Col1 are now only reloaded if the graphics mode really requires it. This applies to fine scrolling text modes, and the text window modes with the GTIA modes (modes 9+64,10+64 and 11+64). This fixes compatibility issues with Atari Tennis and some Lucasfilms intros. - Minor modifications in the FMS: Rename with wildcard was broken, and the FMS no longer tries to load non-valid VTOCs. - The DUP COPY command avoids now trying to overwrite BASIC program memory or other user memory protected correctly by setting APPMEMHI. Some cartridges do not set this Os pointer correctly, though. Mac/65 does not. The new DUP command NEW will erase user memory and make it available for COPY. - Fixed a long standing bug of all Dos 2.XX compatible FMS'es: Directory reading mode did not cooperate with any other operations that would access the directory, and would invalidate the directory access channel. This is no longer the case now. Additionally, reading the directory sets now the EOF warning flag (Y = 3) correctly right before the EOF. - The STATUS command, as specified by DOS 2.0S and DOS 2.5, was actually quite unuseful as it required a file specification which was never supplied by BASIC. The new implementation returns the status of the last CIO command on the same channel if the channel is open, allowing BASIC for example to access the near-EOF warning return code.

Download: Atari++ v1.72
Source: Here