MSU-MD

Overview

MSU-MD enables “MSU-like” Mega CD streaming support on cartridge-based Mega Drive/Genesis hardware. It uses the GenesisPlusGX core to combine CD-quality audio/video streams with ROM-loaded gameplay for modern homebrew ports.

Quick reference

• ROM folder: /userdata/roms/msu-md
• Accepted ROM formats: .md, .zip, .7z, .squashfs
• Emulator/core: libretro: GenesisPlusGX
• System group: genesis, megadrive

ROMs

Keep each MSU-MD-compatible ZIP (matching the board ROM and CRC) in /userdata/roms/msu-md. Do not unpack the archive; GenesisPlusGX expects one compressed file per game. Some ports use .squashfs for streaming assets—those are also accepted.

Emulators

RetroArch (libretro: GenesisPlusGX)

GenesisPlusGX handles the Mega Drive, Master System, Game Gear and Mega CD libraries. Use RetroArch’s Quick Menu ([HOTKEY] + south face button) to access per-core options, lock-on controls, and hardware settings.

Relevant configuration options

ES setting name	REG-Linux.conf_key	Description & values
REDUCE SPRITE FLICKERING	global.gpgx_no_sprite_limit	Disable the 80-sprite limit.
NTSC FILTER (MD)	megadrive.gpgx_blargg_filter_md	Choose Blargg filters (Off, Composite, SVGA, RGB).
FM CHIP	mastersystem.ym2413	Toggle YM2413 / FM-chip audio.
Controller types	megadrive.controller1_md, megadrive.controller2_md, mastersystem.controller1_ms, mastersystem.controller2_ms	Select pads, light guns or paddles per port.
LCD GHOSTING	gamegear.lcd_filter	Simulate Game Gear ghosting.
Extended screen	gamegear.gg_extra	Expand view area for Game Gear titles.

Controls

MSU-MD uses the standard Mega Drive controller mapping on the REG-Linux Retropad. Use RetroArch or EmulationStation’s input remapping for light guns, paddle controllers, or extra keys when needed.

Troubleshooting

• Verify each .zip contains the correct ROM set for the port