Changes since v0.40.0_preview_2
This release is another "preview" of v0.40.0 which will feature a new colour model. Once again, this work is not finished and so the "preview" label is used to emphasise that the results are not optimal or final. The previous preview can been seen here.
Colour Model
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