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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 have 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