Video game console emulator

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Starfox 64 being emulated on a Windows PC using the free Project64 emulator.
This is an explanation of a what a console emulator does. For a list of existing emulators, see list of video game emulators.

A video game console emulator is a type of emulator that allows a personal computer (or in some cases, other video game consoles) to emulate a video game console's hardware and behavior and play games for that platform. Emulators are most often used to play older video games on personal computers and video game consoles, but they are also used to play games translated into other languages or to modify (or hack) existing games. More often than not, emulators offer additional features above and beyond that of the original console, such as multi-controller compatibility (such as PSX controllers being used with N64 games and vice versa), timescale control, higher framerates, higher resolutions, unlocking of gameplay features, memory modifications (like GameShark), and one-click cheat codes. Emulators are also a useful tool in the development process of homebrew demos and the creation of new games for older or discontinued consoles.

Code and data of a game are typically supplied to the emulator by means of a ROM file (a copy of the data contained on a game cartridge) or an ISO disc image (for systems that use optical media). Most game titles retain their copyright even with the original system and games being many years past discontinuation and increasing rarity, so many resort to the obtaining of these games for free on various internet sites rather than purchasing and ripping the ROM from the game (although, this is popular among those who already own the games). Specialized adapters such as the Retrode allow emulators to directly access the data on game cartridges without the need to copy it into a ROM image first.


By the mid-1990s personal computers had progressed to the point where it was technically feasible to replicate the behavior of some of the earliest consoles entirely through software, and the first unauthorized, non-commercial console emulators began to appear. These early programs were often incomplete, only partially emulating a given system, and often riddled with defects. Few manufacturers published technical specifications for their hardware, leaving it to programmers and developers to deduce the exact workings of a console through reverse engineering. Nintendo's consoles tended to be the most commonly studied, for example the most advanced early emulators reproduced the workings of the Nintendo Entertainment System (NES), the Super Nintendo Entertainment System (SNES), and the Game Boy (GB). Programs like Marat Fayzullin's iNES (which emulated the NES), VirtualGameBoy (GB), Pasofami (NES), Super Pasofami (SNES), and VSMC (SNES) were the most popular console emulators of this era. A curiosity was also Yuji Naka's unreleased NES emulator for the Mega Drive, possibly marking the first instance of a software emulator running on a console.[1]

The rise in popularity of console emulation opened the door to foreign video games and exposed North American gamers to Nintendo's censorship policies. This rapid growth in the development of emulators in turn fed the growth of the ROM hacking and fan-translation community. The release of projects such as RPGe's English language translation of Final Fantasy V drew even more users into the emulation scene.

Legal issues[edit]

United States[edit]

As computers and global computer networks continued to advance and emulator developers grew more skilled in their work, the length of time between the commercial release of a console and its successful emulation began to shrink. Fifth generation consoles such as the Nintendo 64, the Sony PlayStation and sixth generation handhelds, such as the Game Boy Advance, saw significant progress toward emulation during their production. This led to an effort by console manufacturers to stop unofficial emulation, but consistent failures such as Sega v. Accolade 977 F.2d 1510 (9th Cir. 1992), Sony Computer Entertainment, Inc. v. Connectix Corporation 203 F.3d 596 (2000), and Sony Computer Entertainment America v. Bleem 214 F.3d 1022 (2000),[2] have had the opposite effect. According to all legal precedents, emulation is legal within the United States. However, unauthorized distribution of copyrighted code remains illegal, according to both country specific copyright and international copyright law under the Berne Convention.[3] Obtaining games through methods not authorized by the developer or publisher is illegal in the United States.

Under United States law, obtaining a dumped copy of the original machine's BIOS is legal under the ruling Lewis Galoob Toys, Inc. v. Nintendo of America, Inc., 964 F.2d 965 (9th Cir. 1992) as fair use as long as the user obtained a legally purchased copy of the machine. However, several emulators for platforms such as Game Boy Advance are capable of running without a BIOS file, using high-level emulation to simulate BIOS subroutines at a slight cost in emulation accuracy.

Official use of emulation[edit]

Due to the demand to play old games on modern systems, consoles have begun incorporating emulation technology.

The most famous of these is Nintendo's Virtual Console. Originally released for the Wii and now present on all Nintendo console releases, the Virtual Console uses software emulation to allow the purchasing and playing of games for old systems on modern hardware. Though only a portion of games are released for it, the Virtual Console has a large collection of games spanning a wide variety of consoles. However, Nintendo has been criticized by some as providing improper emulation (such as providing emulation of handheld games on the Wii U, as opposed to the 3DS). Each game is bundled with a dedicated emulator, which allows that emulator to be designed to run a specific game as well as possible given the limited resources of the console. However, it lacks the enhancements that unofficial emulators provide, and many titles are unavailable. Due to differences in hardware, the Xbox 360 is not natively backwards compatible with original Xbox games. However, Microsoft achieved backwards compatibility with popular titles through an emulator. The PlayStation 3 uses software emulation to play original PlayStation titles[citation needed]. In US 60GB models original PS2 graphics and CPU hardware are present to run PS2 titles, however the PAL and later US models removed the PS2 CPU, replacing it with software emulation working alongside the video hardware to achieve partial hardware/software emulation. In later releases backwards compatibility with PS2 titles was completely removed along with the PS2 graphics chip, and eventually released PS2 titles with software emulation on the PlayStation Store.

Commercial developers have also used emulation as a means to repackage and reissue older games on newer consoles in retail releases. For example, Sega has created several collections of Sonic the Hedgehog games. Before the Virtual Console, Nintendo also used this tactic, such as Game Boy Advance re-releases of NES titles in the Classic NES Series.

Other uses[edit]

One result of ROM images is the potential for ROM hacking. Amateur programmers and gaming enthusiasts have produced translations of foreign games, rewritten dialogue within a game, applied fixes to bugs that were present in the original game, as well as updating old sports games with modern rosters. Software that emulates a console can be improved with additional capabilities that the original system did not have, such as Spatial anti-aliasing, running in High Definition video resolutions, anisotropic filtering (texture sharpening), audio interpolation, save states, online multiplayer options or the incorporation of cheat cartridge functionality. It is even possible to use high-resolution texture pack upgrades for 3-D games if available.

See also[edit]


  1. ^ "Yuji Naka - The Next Level Interview". The Next Level. 15 June 2004. Retrieved 9 June 2014. 
  2. ^ see Midway Manufacturing Co. v. Artic International, Inc., 574 F.Supp. 999, aff'd, 704 F.2d 1009 (9th Cir 1982) (holding the computer ROM of Pac Man to be a sufficient fixation for purposes of copyright law even though the game changes each time played.) and Article 2 of the Berne Convention

External links[edit]