bfirsh/jsnes v2.1.0

2.1.0

on GitHub

Highlights

MMC5 mapper support (Castlevania III and others) plus a batch of PPU, APU, and mapper accuracy fixes.

New mappers

• Mapper 5 (MMC5) — Castlevania III, Uncharted Waters, Laser Invasion, and other late-era titles. Dual CHR bank sets, ExRAM modes, split-screen nametable, direct-CHR sprite 0 hit.

Hardware accuracy

PPU

• Sprite evaluation rewritten for hardware-accurate OAM scan.
• Sprite 0 hit pre-computed for the next scanline for dot-accurate timing.
• Color emphasis bits (NTSC) mapped correctly.
• Grayscale mask fixed (0x20 → 0x30).
• General rendering pipeline and register accuracy improvements.

APU

• Frame counter IRQ timing fixed for hardware accuracy.
• Square sweep negate and overflow mute threshold corrected.

CPU

• NMI handler now sets the I flag.

Mappers

• MMC3: register writes decoded via mirrored address bits.
• Mapper 180: initial PRG bank at $C000 corrected.

Controller

• Strobe now models APU-clock-gated OUT0 updates.

Save states

CPU dataBus and controller state are now persisted. Save states from 2.0.x still load, but dataBus will be zero until the next bus operation.

Packaging

• main/require exports now point to the UMD bundle, fixing Node/CommonJS consumers.
• Game Genie and controller JSON serialization added to type declarations.