Glossary

Accelerated Processing Unit. In the Steam Deck, the combined CPU and GPU chip. Also stands for Audio Processing Unit in older consoles like the NES.

The ratio of width to height of the display. Old games were typically 4:3, while the Steam Deck screen is 16:10. Emulators can stretch, crop, or add borders to handle this difference.

Basic Input/Output System. Firmware built into the original console that initializes hardware and provides system functions. Some emulators require these files to run games.

The rendering system an emulator uses. Common backends include Vulkan, OpenGL, and DirectX. Vulkan is typically best for Steam Deck.

Decorative borders placed around games that do not fill the screen. Often designed to look like arcade cabinets or TV frames.

Compressed Hunks of Data. A compressed disc image format created by MAME. Combines multiple files into one and offers good compression while preserving all data including audio tracks.

In arcade emulation, an alternate version of a game (different region, revision, or bootleg) that shares files with the parent ROM.

In RetroArch, a core is an individual emulator. RetroArch is a frontend that runs many different cores, each emulating a different system.

A visual filter that simulates the look of old CRT televisions, including scanlines, phosphor glow, and curvature. Makes retro games look more authentic.

A database file containing checksums and information about known ROM dumps. Used by ROM managers to verify and organize collections.

The process of copying data from a cartridge, disc, or chip to create a ROM file. Also refers to the resulting file.

Software that mimics the hardware of a game console, allowing games designed for that console to run on different hardware like a PC or Steam Deck.

EmulationStation Desktop Edition. A graphical frontend for launching emulated games. The default interface for RetroDeck.

A Linux application packaging format that bundles apps with their dependencies in a sandboxed container. RetroDeck is distributed as a Flatpak.

A technique where the emulator skips rendering some frames to improve performance. Can cause choppy visuals.

A user interface for browsing and launching games. Examples include ES-DE, Pegasus, and Steam itself when using Steam ROM Manager.

Short for gyroscope. A motion sensor in the Steam Deck that can be used for motion controls, such as aiming in shooters or tilting in Wii games.

High-Level Emulation. An emulation approach that recreates the functions of original hardware in code rather than emulating the hardware directly. Faster but potentially less accurate than LLE.

Software created by hobbyists for consoles, not official releases. Includes games, apps, and utilities made outside official development channels.

The delay between pressing a button and seeing the result on screen. Lower is better, especially for action games and fighting games.

The resolution at which a game is rendered inside the emulator, before being scaled to your screen. Higher internal resolution makes 3D games look sharper.

A disc image file format that contains an exact copy of a CD, DVD, or Blu-ray. Common for PlayStation, PSP, and other disc-based games.

Low-Level Emulation. An emulation approach that precisely emulates the original hardware at a low level. More accurate than HLE but requires more processing power.

A playlist file format. In emulation, used to link multiple disc images together for multi-disc games.

Multiple Arcade Machine Emulator. A project to emulate arcade hardware. Also refers to the ROM format used by arcade emulators.

Online multiplayer functionality in emulators, allowing players on different devices to play together over the internet.

A preservation group that catalogs verified dumps of cartridge-based games. A "No-Intro" ROM set contains only verified, unmodified game dumps.

A graphics API used by some emulators. Generally slower than Vulkan on Steam Deck but has wider compatibility.

In arcade emulation, the main version of a game that clone ROMs reference. Clones often need the parent ROM present to work.

In Steam ROM Manager, a configuration template that tells the tool how to find and add games from a specific system to Steam.

Parallel/Precision Geometry Transform Pipeline. A PlayStation emulator enhancement that fixes geometry wobble and texture warping in 3D games.

A preservation group that catalogs verified dumps of disc-based games. A "Redump" image is a verified, accurate copy of an original disc.

A multi-system emulator frontend that runs various emulator cores. Used by both EmuDeck and RetroDeck for many retro systems.

Read-Only Memory. In emulation, refers to a digital copy of a game, whether from a cartridge (actual ROM) or disc (technically a disc image, but commonly called ROM).

A modified version of a game, created by fans. Can range from simple tweaks to entirely new games built on an existing game's engine.

Revolution Compressed. Dolphin's modern compressed format for GameCube and Wii games. Offers the best compression while preserving all data.

A snapshot of the emulator's complete state at a specific moment. Allows saving and loading from any point in a game, unlike in-game saves.

A tool that downloads game artwork, descriptions, and other metadata from online databases like ScreenScraper or SteamGridDB.

A visual effect applied to the game image. Can simulate CRT displays, smooth pixels, or add other graphical enhancements.

An emulator that runs independently, not as a RetroArch core. Examples include Dolphin, PCSX2, and RPCS3.

Steam's controller configuration system. Allows remapping buttons, using gyro, and creating custom layouts for any game launched through Steam.

Thermal Design Power. The amount of power the Steam Deck's APU is allowed to use. Higher TDP means more performance but also more heat and shorter battery life.

A technique to smooth textures in 3D games. Options include bilinear, trilinear, and anisotropic filtering, with anisotropic generally looking best.

Vertical Sync. Synchronizes the game's frame rate with the display's refresh rate to prevent screen tearing. May add slight input lag.

A modern graphics API. Generally offers the best performance on Steam Deck and is preferred over OpenGL for most emulators.

A modification that forces a game designed for 4:3 displays to render in 16:9 or 16:10. May cause visual glitches in some games.