z26 v4.00 is released. z26 is an Atari 2600 emulator. z26 is Copyright ©1997-2011 by John Saeger and contributors. z26 is released subject to the terms and conditions of the GNU General Public License Version 2 (GPL). z26 comes with no warranty.

z26 v4.00 Changelog:
* The classic z26 graphics engine as implemented in the DOS version of z26 has been ported from assembly language to C. Generally speaking, we now have accuracy that is similar to the original z26 that ran on DOS. The original version of this engine basically came into being in z26 version 1.31 in 1999. It was the first 2600 emulator to implement support for “early HMOVE.” The engine in z26 4.00 does it like the original. We also include an implementation of the “multi-sprite trick” which we first supported in z26 version 1.29, also from 1999.
* This version now runs on the Raspberry Pi and it will run games at full speed even if the processor is throttled. For example if you have a low-quality power supply and the voltage is sometimes too low, or if the chip overheats, throttling kicks in. I test this by underclocking the processor to 600 Mhz which is the speed the processor runs at if it’s throttled.
* We now use SDL 2.0 so we can switch from windowed mode to full screen without restarting the emulator.
* Also thanks to SDL 2.0 we can turn monitor synchronization on and off. This lets us enable synchronization automatically in many cases where the OpenGL driver has disabled it, and it lets us do full-speed benchmarking. To do benchmarking turn off the Vsync option in the Video menu and turn on FPS display in the Interface menu.
* Dropped support for playing certain bad ROM dumps from the 1990s. This allowed a simpler and arguably more accurate handling of VSYNC and VBLANK.
* Dropped support for PAL color loss. Evidently not all PAL console/TV combinations do color loss anyway.
* You can specify the color scheme of a ROM by including one of the strings NTSC, PAL, or SECAM as part of the filename.
* We’ve added automatic recognition for some additional ROMS.
* Dropped support for interlaced games. This may or may not be temporary, but I needed the display code to be a little simpler.
* Dropped the game height adjustment from the video menu. It tended to mess up the scanlines.
* Dropped DSP and sound queue size adjustments from the sound menu. They’re really not needed these days.
* Dropped support for the Stelladaptor. I’ve never had one and I don’t even really know what it is, so I’m not sure how I would support this option anyway. There may be some more modern way of hooking up real controllers that I might like to look into, and whatever it is I’d like to have one for myself before enabling it in z26. Personally I mostly use the keyboard anyway, unless I’m using a mouse. It’s simply convenient.
* Dropped support for mouse rude and grab input options in the interface menu. If you’re running full screen you don’t need them. I suggest running full screen. It’s better that way.
* Modified (fixed?) [3E] bankswitching so that some demos are now more playable.
* Limited display to 240 scanlines for NTSC games. This cleans up the junk at the bottom of Demon Attack and some other games. PAL and SECAM games still get the full 256 scanlines.
* You can specify the bankswitch scheme of a ROM by giving the ROM file a filename extension using a bankswitch abbreviation, or by enclosing the bankswitch abbreviation in square brackets. For example, one of the large Tigervision schemes is [3F+]. So you can name the ROM filename.3f+ and z26 will recognize the bankswitch scheme of that ROM as 3f+ or simply enclose 3f+ in square brackets thus: [3f+] and likewise z26 will recognize it. The other options are listed below under the game menu.
* Restored the ability to shift game image up, down and back to the original position with PgUp, PgDn, and Home keys.
* The configuration files z26.cli and z26.gui are now built in your home directory. To restore defaults delete these files from your home directory.
* The Fast Sharp texture is now the default. The fast textures do not support scanlines so scanline options are not shown in the video menu if a fast texture is selected.
* Changed mac build system to use command line tools. Thanks to Joseph Long for showing how to do this. (https://joseph-long.com/writing/app-...th-a-makefile/)
* The distribution now includes a small wave file z26.wav which is used as part of the sound initialization on Linux platforms. After compiling on Linux, if you move the executable, please be sure to move z26.wav along with the executable. Thanks to Nick Arnoeyts for the code to play a wave file (https://gist.github.com/armornick/3447121).
* The ROM lister now begins in your home directory, so it no longer matters where you place the z26 executable. On Windows make sure to include SDL2.dll in the same directory as z26.exe, and on Linux make sure to include z26.wav in the same directory as z26.

http://www.whimsey.com/z26/z26.html