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Sega - MS/GG (Gearsystem)

Background

Gearsystem is an open source, multi-platform, Sega Master System / Game Gear / SG-1000 emulator written in C++.

  • Highly accurate Z80 core, including undocumented opcodes and behaviour like R and MEMPTR registers.
  • Multi-Mapper support: SEGA, Codemasters, SG-1000 and ROM only cartridges.
  • Automatic region detection: NTSC-JAP, NTSC-USA, PAL-EUR.
  • Internal database for rom detection
  • Highly accurate VDP emulation including timing and SMS2 only 224 mode support.
  • Audio emulation using SDL Audio and Sms_Snd_Emu library.
  • Battery powered RAM save support.
  • Save states.
  • Game Genie and Pro Action Replay cheat support.
  • Runs on Windows, Linux, Mac OS X, Raspberry Pi, iOS and as a libretro core (RetroArch).

The Gearsystem core has been authored by

  • Ignacio Sanchez

The Gearsystem core is licensed under

A summary of the licenses behind RetroArch and its cores can be found here.

BIOS

Not required.

Extensions

Content that can be loaded by the Gearsystem core have the following file extensions:

  • .sms
  • .gg
  • .sg
  • .bin
  • .rom

RetroArch database(s) that are associated with the Gearsystem core:

Features

Frontend-level settings or features that the Gearsystem core respects.

Feature Supported
Restart ✔
Screenshots ✔
Saves ✔
States ✔
Rewind ✔
Netplay ✕
Core Options ✔
RetroAchievements ✔
RetroArch Cheats - Game Genie ✔
RetroArch Cheats - Pro Acion Replay ✔
Native Cheats ✕
Controls ✔
Remapping ✔
Multi-Mouse ✕
Rumble ✕
Sensors ✕
Camera ✕
Location ✕
Subsystem ✕
Softpatching ✔
Disk Control ✕
Username ✕
Language ✕
Crop Overscan ✕
LEDs ✕

Directories

The Gearsystem core's library name is 'Gearsystem'

The Gearsystem core saves/loads to/from these directories.

Frontend's Save directory

File Description
*.srm Cartridge battery save

Frontend's State directory

File Description
*.state# State

Geometry and timing

  • The Gearsystem core's core provided FPS is 60 for NTSC games and 50 for PAL games
  • The Gearsystem core's core provided sample rate is 44100 Hz
  • The Gearsystem core's base width is 256 for Master System / SG-1000 games and 160 for Game Gear games
  • The Gearsystem core's base height is 192 for Master System / SG-1000 games and 144 for Game Gear games
  • The Gearsystem core's max width is 256 for Master System games and 160 for Game Gear games
  • The Gearsystem core's max height is 224 for Master System games and 144 for Game Gear games
  • The Gearsystem core's core provided aspect ratio is 4:3 for Master System / SG-1000 games and 10:9 for Game Gear games

Joypad

User 1 input descriptors RetroPad Inputs
1
Start
Up
Down
Left
Right
2

Compatibility

See also

Sega - Game Gear

Sega - Master System - Mark III

Sega - SG-1000