What is emulation?

Emulation is the use of an application, program, or device to imitate the behaviour of a different program or device. Some common uses of emulation include running console-based video games via an application or computer, running an OS on a piece of hardware it was not originally engineered for or running applications on an operating system that it was not initially written for.

Emulation can also be used to imitate the function of another piece of hardware to allow the connecting of devices or connecting to a mainframe computer.

Types of emulation

The two most well-known uses of emulation are covered in our definition as these examples best explain its uses. However, emulation itself can be broken down into three main types. These are: logic simulation, functional emulation, and video game emulation.

The use of a computer programme to simulate the operation of a digital circuit, such as a processor, is known as logic simulation. This is done after a digital circuit has been designed in logic equations but before the circuit is physically built.

The use of a computer programme to simulate the execution of a second computer programme written in symbolic assembly language or compiler language rather than binary machine code is known as functional emulation. Programmers can use a functional emulator to execute and trace selected sections of source code to look for programming errors (bugs) without generating binary code.

Video game emulation uses programmes that allow a computer or video game console to emulate another video game console. They are mostly used to play older video games from the 1980s to the 2000s on modern personal computers, video game consoles, and handheld devices that are custom made for this purpose. They are also used to translate games into other languages, modify existing games, and in the creation of “home-brew” DIY demos and new games for older systems.

The legality of video game emulation

The process of downloading video game emulators is completely legal. They are similar to other programmes you might download, such as a word processor or music player. It is illegal to download and upload ROMs, which are the specific game files used to play video on the emulator. However, if you use a ROM file that you own or have purchased from an authorised source or subscription service (such as Nintendo Switch Online, which emulates old games via a subscription service for you), you will not be breaking any laws.

Video game emulators such as RetroArch, OpenEmu, or Dolphin Emulator are programmes that users download to play old games on a laptop, phone, or emulation device. Consider the programmes to be like a video game MP3 player: the programme is useless without the files that allow it to run, and those files are the ROMs. It is perfectly legal to buy a song or album from iTunes and then download and stream it on your music player software. The illegal aspect would be if you downloaded the music from an unlicensed website or service and then imported it into your music player software. The same is true for video games.

Users can use specific software to rip files from your favourite game carts and discs before transferring them to a computer. These ripped files will then be playable in emulators.