Homebrew dev EkeEke is back on the wiibrew scene to update his Genesis Plus GX, an enhanced version of the Sega Genesis / Sega Megadrive / Sega Master System emulator for the Nintendo Wii based on Charles MacDonald's Genesis Plus project.

Changelog:

Core/VDP

• added support for Master System compatibility mode (Z80 ports access mode), incl. Mode 5 rendering.
• added Mode 4 rendering for both Genesis & Master System modes.
• added alternate BG planes rendering functions (should be faster on PPC architectures).

Core/IO

• added support for Master System compatibility mode (Z80 ports access mode).
• added Master System peripherals emulation (Control Pad, Paddle, Sports Pad & Light Phaser).
• added XE-1AP (analog controller) emulation.
• added Activator emulation.

Core/Extra]

• added support for all known Master System cartridge mappers.
• added copy-protection hardware emulation for a few MD unlicensed games: fixes 777 Casino (crash when talking to bunny girls).

(NB: most of those unlicensed games seem to have been already patched by ROM dumpers, main purpose is documenting them)

• added support for Top Shooter arcade board controller. (A=Shoot, B=Bet, C/RIGHT=Coins, START=Start, hold UP on startup to enter service mode)
• improved King of Fighters 98 mapper emulation (registers address decoding is now 100% accurate)
• fixed Game Genie when several codes affect same ROM address.
• fixed EEPROM types for Brian Lara Cricket & NBA Jam TE (verified on real cartridges)

Core/General

• added Master System compatibility mode emulation (automatically enabled when loading ROM file with .sms extension).
• improved savestate stability & compatibility (support for old 1.4.x savestates is preserved)
• various code cleanup & comments.

Gamecube/Wii

• fixed cheat codes handling when several codes affect same ROM address.
• improved input controller detection on menu exit.
• improved key remapping dialog box to match emulated device
• changed Menu key for Gamecube controller to allow MODE button mapping
• fixed DVD not being unmounted on swap (memory leak)

Wii only

• added USB mouse support for Sega Mouse emulation
• compiled with latest libogc: improves USB compatibility & fixes stability issues with Wiimotes.