Video game console emulator

• 1. Origins And Early Development

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  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. The first unauthorized, non-commercial console emulators began to appear during this period. These early programs were often incomplete and only partially emulated a given system, resulting in visible defects. Few manufacturers published technical specifications for their hardware, which left programmers to deduce the exact workings of a console through reverse engineering. Nintendo's consoles tended to be the most commonly studied systems. The most advanced early emulators reproduced the workings of the Nintendo Entertainment System, the Super Nintendo Entertainment System, and the Game Boy. The first such recognized emulator was released around 1996 as one of the prototype projects that eventually merged into the SNES9X product. Programs like Marat Fayzullin's iNES, VirtualGameBoy, Pasofami, and VSMC became the most popular console emulators of this era. A curiosity emerged when Yuji Naka created an unreleased NES emulator for the Genesis, possibly marking the first instance of a software emulator running on a console itself. As the Internet gained wider availability, distribution of both emulator software and ROM images became more common, helping to popularize these tools.

• 2. Technical Implementation Methods

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  Emulators can be designed in three ways: purely operating in software, purely operating in hardware, or mixed systems. Purely software emulation is the most common form, exemplified by MAME using ROM images. Purely hardware solutions include the ColecoVision adapter that accepts Atari VCS cartridges. An emulator is typically created through reverse engineering of the hardware information to avoid conflicts with non-public intellectual property. Some information may be made public for developers regarding the hardware specifications, but there are often layers of information that remain trade secrets. Operating code stored in the hardware BIOS may be disassembled to be analyzed in a clean room design. One person performs the disassembling while another person documents the function of the code separately. Once enough information is obtained regarding how the hardware interprets game software, an emulation on the target hardware can then be constructed. Emulation developers typically avoid any information from untraceable sources to avoid contaminating the clean room nature of their project. In 2020, a large trove of information related to Nintendo consoles was leaked, and teams working on emulators like Dolphin stated they were staying far away from the leaked data to avoid tainting their projects.

• 3. Legal Battles And Copyright Law

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  Legal attention was drawn to emulation with the release of UltraHLE, an emulator for the Nintendo 64 released in 1999. The Nintendo 64 was still Nintendo's primary console when this occurred, as its next console would not arrive until 2001. UltraHLE was the first emulator released for a current console and it was seen to have some effect on sales, though the degree compared to diminishing sales on aging consoles remained unclear. Nintendo pursued legal action to stop the emulator project, and while the original authors ceased development, others continued using the source code. Since then, Nintendo has generally taken the lead in actions against emulation projects or distributions of emulated games from their consoles. Consistent failures by manufacturers such as Sega v. Accolade in 1992 and Sony Computer Entertainment Inc. v. Connectix Corporation in 2000 have had the opposite effect. These rulings established that emulators developed through clean room design are legal under United States law. The Librarian of Congress codified these rules as allowed exemptions to bypass technical copyright protections on console hardware under the Digital Millennium Copyright Act. Unauthorized distribution of copyrighted code remains illegal according to both country-specific copyright and international copyright law under the Berne Convention.

• 4. Industry Perspectives And Preservation

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  Outside of official usage, emulation has generally been seen negatively by video game console manufacturers and game developers. The largest concern is the nature of copyright infringement related to ROM images typically distributed freely without hardware restrictions. This directly impacts potential sales of emulated games and thus the publishers and developers. Further, emulation challenges the industry's use of the razorblade model where consoles are sold near cost and revenue is obtained from licenses on game sales. With console emulation being developed even while consoles are still on the market, manufacturers are forced to continue innovating and move quickly onto new technology. Alternatively, emulation enhances video game preservation efforts by shifting game information from outdated technology into newer formats. Concerns about cost, availability, and longevity of game software and console hardware have also been cited as reasons for supporting emulator development. Some users see emulation as a means to preserve games from companies that have long-since gone bankrupt or disappeared from the industry. In November 2021, Phil Spencer stated he hoped for video game companies to eventually develop legal emulation allowing users to play any past game they already owned a copy of. He characterized this goal as a great North Star for the industry to aim towards in the future.

• 5. Adoption By Major Manufacturers

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  Due to high demand for playing old games on modern systems, consoles have begun incorporating emulation technology. Nintendo's Virtual Console was originally released for the Wii but is present on the 3DS and Wii U. The service uses software emulation to allow purchasing and playing games for old systems on modern hardware. Though not all games are available, the library spans titles originating from the NES, Super NES, Game Boy, Game Boy Color, N64, GBA, DS, and Wii. It also includes Sega Master System, NEC TurboGrafx-16, and SNK Neo Geo titles. Virtual Console titles have been downloaded over ten million times. Each game is distributed with a dedicated emulator tweaked to run it as well as possible. Until firmware update 4.0.0, the Nintendo Switch contained an embedded NES emulator running Golf as an Easter egg tribute to former president Satoru Iwata who died in 2015. Microsoft achieved backwards compatibility with popular Xbox titles through emulation starting the 15th of June 2015 when announcing the Xbox One would be compatible with Xbox 360 games. Sony used software emulation to play original PlayStation titles on the PlayStation 3, eventually removing PS2 hardware components to replace them with software emulation.

• 6. Enhanced Functionality And Modding

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  Although the primary purpose of emulation is making older video-games execute on newer systems, there are several advantages inherent in the extra flexibility of software emulation. Disk image loading allows amateur programmers to modify actual game files within ROMs more easily than physical media. Enthusiasts have produced translations of foreign games, rewritten dialogue, applied fixes to bugs, and updated old sports games with modern rosters. Software that emulates a console can offer enhanced graphical capabilities such as spatial anti-aliasing and upscaling framebuffer resolution to match high definition displays. Emulation software may also offer improved audio capabilities including decreased latency and better audio interpolation. Enhanced save states allow users to save a game at any point for debugging or re-try purposes. Some emulators feature options to quickly boot a game bypassing the manufacturer's original splash screens. Furthermore, emulation software offers online multiplayer functionality and the ability to speed up or slow down emulation speed. This allows users to fast-forward through unwanted cutscenes or disable the framelimiter entirely for benchmarking purposes. Many emulators make it far easier to load console-based cheats without requiring expensive proprietary hardware devices like those used by GameShark.