crater

Free plan LinuxMac

What crater is

Crater is a free Sega Game Gear emulator written in C, with a Z80 assembler and disassembler included. It loads ROMs from its roms directory or from a command-line path, and offers fullscreen mode, integer scaling in a window, and a square-pixel option. Keyboard and joystick or controller input are supported; controller mappings can be defined in a gamecontrollerdb.txt file. For compatible games, it saves cartridge RAM to a .sav file, with options for a custom save location or disabling saves. The assembler converts Z80 assembly into a Game Gear ROM image and is described as complete. The disassembler attempts to turn ROM images into assembly but cannot distinguish code from data. Most games are described as playable with minor bugs, though Crater lacks audio, some uncommon CPU instructions, and advanced graphics features. Save states and custom keyboard mappings are not supported. Building requires a modern C11 compiler and SDL 2; only OS X and Linux are tested.

Who it suits

Crater suits people interested in playing Game Gear ROMs or exploring emulator development, particularly those comfortable building software with C11 and SDL 2.

What it does well

Free and distributed under the MIT License
Includes a complete Z80 assembler
Supports cartridge RAM saves for compatible games
Most games are described as playable

What to know first

No audio support
Save states are not supported
Disassembler cannot distinguish code from data
Building requires a C11 compiler and SDL 2

Limits

The free plan costs nothing. The emulator lacks audio support, some uncommon CPU instructions, and advanced graphics features; save states are not supported. The disassembler cannot distinguish code from data.

Plans

Plan	Billed and limits	Price
Free	MIT-licensed software · requires a C11 compiler and SDL 2	Free

As github.com lists them, read 7 Oct 2026. The maker's own page has the final word.

Getting started

Open the project website on GitHub.
Use a Linux or macOS system; the project says OS X and Linux are tested.
Install a modern C11 compiler and SDL 2.
Build the program with make.
Load a ROM from the roms directory or provide its path on the command line.

Verdict

Crater pairs Game Gear emulation with Z80 assembly tools, but its documented gaps include audio, save states, and some graphics features. It may suit users willing to build it and work within those limitations.

Questions

How much does crater cost?

The listed plan is free, and the pricing model is free.

Which platforms does crater support?

The listed platforms are Linux and macOS. The project says it tests on OS X and Linux.

Does crater include source code?

Yes. Source is available, and the project is distributed under the MIT License.

Who makes crater?

GitHub identifies the repository owner as Ben Kurtovic.

Can it save game progress?

For compatible games, it saves cartridge RAM to a .sav file. Save states are not supported.

What does the disassembler do?

It attempts to turn ROM images into assembly, but cannot distinguish code from data.

Facts from crater's own pages

Assembler: The assembler converts Z80 assembly source into a Game Gear ROM image, and the project describes it as complete. · github.com, 7 Oct 2026
Assembler and disassembler: The built-in tools convert Z80 assembly to ROM images and attempt to disassemble ROM images into assembly. · github.com, 7 Oct 2026
Build requirements: Building crater requires a modern C11 compiler and SDL 2; the project says only OS X and Linux are tested. · github.com, 7 Oct 2026
Controller mappings: Crater uses SDL controller mappings and lets users define mappings in a gamecontrollerdb.txt file. · github.com, 7 Oct 2026
Disassembler: The disassembler works but cannot distinguish code from data, which the project says limits its usefulness. · github.com, 7 Oct 2026
Disassembler limitation: The disassembler cannot yet distinguish code from data, which the project says limits its usefulness. · github.com, 7 Oct 2026
Display options: Crater supports fullscreen mode, integer scaling in windowed mode, and an option to force square pixels. · github.com, 7 Oct 2026
Distribution: The GitHub releases page states that there are no releases, and the README describes building the program with make. · github.com, 7 Oct 2026
Emulation status: The emulator is almost fully functional, and most games are playable with minor bugs. · github.com, 7 Oct 2026
Input: Crater supports keyboard and joystick/controller input, but custom keyboard mappings are not yet supported. · github.com, 7 Oct 2026
Intended audience: The maker describes writing an emulator as a fun learning project. · github.com, 7 Oct 2026
Known gaps: The emulator lacks audio support, a few uncommon CPU instructions, and some advanced graphics features. · github.com, 7 Oct 2026
License: Crater is distributed under the MIT License, which permits free use, copying, modification, distribution, sublicensing, and sale subject to its conditions. · github.com, 7 Oct 2026
Maker: GitHub identifies the repository owner as Ben Kurtovic and lists New York City as his location. · github.com, 7 Oct 2026
Platforms: The project says only OS X and Linux have been tested. · github.com, 7 Oct 2026
Project status: The emulator lacks audio support, some uncommon CPU instructions, and advanced graphics features, while most games are described as playable with minor bugs. · github.com, 7 Oct 2026
Purpose: Crater is a Sega Game Gear emulator with an included Z80 assembler and disassembler, written in C. · github.com, 7 Oct 2026
Run games: Crater can load ROMs from its roms directory or from a path supplied on the command line. · github.com, 7 Oct 2026
Save data: For games that support it, crater saves cartridge RAM to a .sav file and supports custom save locations or disabling saves. · github.com, 7 Oct 2026
Save states: Save states are not yet supported. · github.com, 7 Oct 2026
Save support: For compatible games, crater saves cartridge RAM to a .sav file; save states are not yet supported. · github.com, 7 Oct 2026

Where crater stands on Freedom251

Game Gear Emulators#9 of 31