MAME-NES v2.0 is released. This branch contains a major NES/Famicom accuracy update for MAME. The main M6502/NES CPU timing path, APU, and PPU have been heavily reworked toward cycle-accurate behavior. The goal of this work is to improve hardware accuracy while keeping the implementation compatible with MAME's existing NES/Famicom architecture.

MAME-NES Changelog:
This release moves PPU timing out of the APU and into the PPU itself. Previously, each APU tick triggered three PPU ticks. The PPU now manages its own timing, allowing all four NTSC CPU/PPU timing alignments to be emulated.
Choose Phase 0–3 or Random under Tab → Machine Configuration → CPU/PPU Alignment. Random selects an alignment using weighted probabilities, and the selection takes effect when the machine resets.
All four phases pass the $2007 alignment tests, RMW2007Test, and AccuracyCoin in testing.
Warrio Woods flicker occurs on phase 1
read2004.nes - looks correct on phase 0 and is missing a starting FF for phases 1-3(normal?)
demo_ntsc - correct on all phases
scanline.nes - looks correct on phase 0 and has some corruption for phases 1-3 (normal?)
PaletteCorruption.nes - correctly detected the selected phase
INC2007Alignment.nes - correctly detected the selected phase

Download: MAME-NES v2.0
Source: Here