Gopher2600 v0.57.0 is released. Gopher2600 is an emulator for the Atari 2600. Whilst the performance is not as efficient as some other emulators it is none-the-less suitable for playing games, on a reasonably modern computer, at the required 60fps. (The development machine for Gopher2600 has been an i3-3225, dating from around 2012.)

Gopher2600 changelog:
Television
SECAM colour generation is now correct
Video Recording (improvements)
incoming video is now recorded at the specificed rate of the emulated television, not the monitor
ie. 60Hz for NTSC and 50Hz for PAL
output video is always 60fps
synchronisation of video and audio is constant even over long recordings
console reset does not interrupt recording
each video session started/stopped with hotkey (ctrl+v) creates a new video file
ffmpeg still required
Supercharger Demo Unit
support for the Supercharger Demo Unit
the ROM dump can be downloaded from
https://forums.atariage.com/topic/390261-starpath-demonstration-unit-rom-dump/page/5/#findComment-5863403
Debugger
pixel indicator in Playfield window is now correct (issue #54)
television window shows CPU Cycle information for the scanline, in addition to Clock (issue #55)
ports window includes Latch and Grounded toggle (issue #56)
added SCREENSHOT command
screenshotting has been available for a long time when in playmode
this command gives the ability to screenshot from the debugger
command is also usable from HEADLESS mode
ARM
corrected behaviour of MAM (ARM7TDMI)
the size of the MAM latch was too large in previous version
the real size is 128 bits (or 4 instructions). I had set it to 128 bytes (32 instructions)
the practical effect is that timing constraints should now be more like real hardware
this only affects the Harmony type cartridges. PlusCart type cartridges do not have a MAM
stack pointer tamper protection
Other
state of INPTx and SWCHA correct after peripheral change
including when the peripheral port is left empty (issue #56)
added UASW as a way to indicate a UA cartridge with 'swapped' hotspots
https://forums.atariage.com/topic/390683-beamrider-from-digivision-jvp-logo-rom-dumped-need-help/
savekey would sometimes leave SWCHA in an incorrect state
added 'Export Max Function Cycles to JSON' option to coprocessor profiler
added support for PAL supercharger BIOS
B&W television option
corrected location of stack for ACE cartridges
use of symbols in the debugger is now case-insensitive
changed output of WATCH and SYMBOL commands
binary fingerprinting of CV cartridge mapper

Download: Gopher2600 v0.57.0
Source:Here