Gopher2600 v0.40.0-preview3 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:
In this preview I have changed the output value of "black" as produced by NTSC Colour-Lum value $00. For PAL and SECAM there are more values that produce "black" and this applies to them too. The purpose of this change is to make it the same value of the "black" produced by VBLANK.
Without going into too much detail, the purpose of this change is to ensure that both types of black (the one produced by VBLANK and the one produced by Colour-Lum $00) are affected by the brightness/contrast controls equally, which is what can be observed on real hardware.
There are very few games where the two blacks can be seen together but a good example is Boom by Chris Walton. The screen with the bouncing AtariAge logo uses VBLANK as a convenient way of creating black.
In the image above the darker black is produced by VBLANK and the lighter black by Colour-Lum $00.
The difference can be reduced by lowering the brightness but that wouldn't be a correct solution.The correct solution is for the two blacks to be the same value.
Other Changes
Corrected detected of "PAL60" in filename
This controls the specification of the emulated television
DPC (Pitfall II) fingerprinting
The detection for DPC is based purely on size of the ROM file
Problem identified in #36
DPC Random Number Generator
Corrected random number algorithm to more closely match DPC patent
Pumped on every cartridge access and not just on 'non-volatile' access
ARM Timers
ARM timers more efficiently updated
Small improvement in performance
ELF Performance
Small efficiency improvements

Download: Gopher2600 v0.40.0-preview3
Source:Here