Emulation | Code Like It's 198x

In May 1997 Edge told its readers that “anyone with a moderately fast PC and a few hundred megabytes of hard-drive space can be the curator of their own 20,000-game living museum, containing perfect replications of around 30 old computers and consoles (ie practically all of them), and over 50 coin-op games.” The software doing the replicating was written by hobbyists and given away. Edge thought that mattered more than nostalgia: “emulation isn’t (mostly) actually about nostalgia at all. It’s about history.”

An emulator is a program that behaves like another machine’s hardware so closely that software written for that machine runs on it unchanged. The old program does not know the difference. This entry follows how emulators spread from the early 1990s, the court cases of 1999 and 2000, and their role in preserving and studying software.

How an emulator works

An emulator must reproduce the behaviour the old software depends on: processor instructions, memory, display, sound and the timing between them. Implementations make different choices about which details to reproduce directly and where a faster substitute is sufficient.

Emulation techniques explains interpretation, dynamic recompilation, display emulation and synchronisation through accounts from emulator developers and contemporary reviewers. Those engineering choices helped determine which machines people could emulate, and on what equipment.

The early 1990s

Emulators of the 8-bit home computers were already circulating by 1991. In May of that year an advertisement for an Amiga public-domain library in the first issue of Amiga Shopper listed a “Spectrum Emulator”, a “C64 Emulator” and an “ST Emulator” among its disks.

On the PC, by 1994, Gary Penn could write in PC Gamer that “thanks to this one piece of hardware and two pieces of software” it was “possible to play all the games from one old format (the Sinclair Spectrum) and most of the games from another (the Commodore 64)”. He also reported the first trouble: “bulletin boards and other Shareware libraries have been forced to remove such emulators, along with the ported-over games, from their catalogues, because technically they contravene the original software’s copyright.” Penn argued that since he still owned the machines and the tapes, the copies on his hard disc were back-ups for personal use.

The 1997 wave

By 1997 the PC was fast enough for most of the 8-bit era, and the internet made emulators easy to share. Edge spent two issues surveying eighteen classic machines and the emulators for each. For the Commodore 64 it named “the big two”, PC64 and C64S: PC64 cost £15 to register, while C64S cost “a rather uncomfortable $60”. It called the Spectrum scene “possibly the liveliest one around”, centred on the newsgroup comp.sys.sinclair, with an archive “fed by a constant stream of games, often by their original authors”. For the NES the new favourite was NESticle, “apparently knocked together for fun in about three weeks” by a team called Bloodlust Software. Emulators were small enough to carry on a floppy disk. The latest Space Invaders emulator, Edge noted, took up “a mind-bogglingly tiny 3K”.

The same year brought MAME, released in February 1997 by Nicola Salmoria, which gathered arcade emulation into one program. The emulators that grew into today’s standard tools for single machines have their own entries: VICE for Commodore’s 8-bit machines, Fuse for the Spectrum, WinUAE and FS-UAE for the Amiga, and Mesen and FCEUX for the NES.

1999: the console makers respond

Emulating a machine that was no longer sold had been tolerated. Early in 1999 three programs emulated consoles that were still in the shops, and the owners objected.

UltraHLE. Released on 28 January 1999 by two programmers calling themselves Epsilon and RealityMan, UltraHLE ran Super Mario 64 and The Legend of Zelda: Ocarina of Time on a Nintendo 64 emulator for Windows that was only about 220K compressed. Its authors took their site down within hours, said they had written it “to see if it could be done”, and declared the project discontinued, but copies had already spread. Nintendo’s Beth Llewelyn told Edge: “They obviously had to circumvent our security chip. It promotes continued piracy.” To PC Zone she said Nintendo was “very disturbed” that the authors had distributed “a product designed solely to play infringing copies of copyrighted works”, and that it was “taking measures to further protect and enforce our intellectual property rights which, of course, includes the bringing of legal action.” Edge admired UltraHLE “as a piece of coding” but found “the issues and complexities that it introduces are less palatable”.

Connectix Virtual Game Station. Connectix showed a PlayStation emulator for the Macintosh at Macworld in January 1999 and sold it for $50. Unlike UltraHLE it played the original game discs. Sony sued in the federal court in San Francisco on 27 January 1999. The court first refused Sony a temporary restraining order, and Connectix’s chief executive, Roy McDonald, told Edge: “Reverse engineering is not illegal.” In spring 1999 the court granted Sony a preliminary injunction. Connectix had to stop shipping the program and stop work on products using Sony’s BIOS, the PlayStation’s built-in system code, which it had copied repeatedly while working out how it behaved.

Connectix appealed. The US Court of Appeals for the Ninth Circuit reversed the injunction in its ruling of 10 February 2000. It held that “intermediate copies made and used by Connectix during the course of its reverse engineering of the Sony BIOS were protected fair use, necessary to permit Connectix to make its non-infringing Virtual Game Station function with PlayStation games”, and found no evidence for Sony’s trademark claim. A year later Sony bought the Virtual Game Station from Connectix, and the product was withdrawn. Computer Gaming World reported that “with the acquisition, Sony now owns all core assets related to the Virtual Game Station”.

bleem! A small company, bleem!, released a PlayStation emulator for Windows PCs in spring 1999, sold for download from its website. PC Zone reported 600,000 hits on the site’s first day and 150,000 downloads of the demo. Sony failed to get a temporary restraining order against it too, and Edge reported that the finished program shipped after 500,000 demo downloads. Sony’s case went on, alleging that bleem! had infringed its copyright in the BIOS. Bleem! filed counterclaims, some over Sony’s efforts to have its stand removed from the E3 trade show in May 1999. After the Connectix ruling, bleem!’s Sean Kauppinen told APC: “The biggest thing it [the Connectix case] does is set a judicial precedent for us.” In May 2000 the company announced bleemcast!, which ran PlayStation games on Sega’s Dreamcast; it closed in 2001. Looking back in 2004, Computer Gaming World wrote that Sony had “sued Bleem and Connectix into submission a few years back”.

The Vault’s entry on Sony v. Connectix covers the case in more detail.

Where the law settled

The period cases drew a line that still holds in outline, though the details depend on the country:

The emulator itself. In the United States, writing an emulator by reverse engineering was ruled fair use in Sony v. Connectix. Edge put it plainly in 2002: “It is completely legal to create an emulation program but there’s still a grey area when it comes to playing a game using one.” APC warned in 2000 that Australian copyright law gave reverse engineering much narrower protection, so the same emulator might not be safe there.
System ROMs. Many machines need their original firmware to run, and that firmware is copyrighted. Some owners licensed it. UAE, the Amiga emulator, “refuses to work without a valid image of the Amiga Kickstart ROM”, and in 2000 Cloanto was selling a licensed Kickstart with UAE as Amiga Forever. Amstrad allowed the CPC’s ROMs to be distributed with emulators as long as its copyright message went with them.
Games. The games are copyrighted too. Sharing copies of them, and of system ROMs, without permission brought much of the legal action, from the shareware libraries of 1994 to the fan site Dave’s Classics, which Sony sued in 1999 for distributing the PlayStation BIOS.

In 2006 the Internet Archive won the renewal of an exemption from the US Digital Millennium Copyright Act that lets libraries and archives break the copy protection on obsolete software to preserve it (see Internet Archive).

Beyond playing

Emulators changed how old software is studied and played. Save states and frame-by-frame control made tool-assisted speedruns possible. In 2004 Retro Gamer described a much-shared Super Mario Bros. 3 video that had been assembled from save states and several sessions, which many viewers took for a real run (see speedrunning). Front ends such as RetroArch put many emulators behind one interface. The Internet Archive runs old computers inside a web browser, and FPGA systems such as the MiSTer recreate the hardware itself in programmable logic. The Vault’s emulation techniques entry goes further into the methods.

Sources

Edge issue 45, May 1997, “The forgotten history of the videogames industry”, part 1: the “living museum” quote, “It’s about history”, the eighteen machines, and the C64 emulators PC64 and C64S.
Edge issue 46, June 1997, “The forgotten history of the videogames industry”, part 2: the Spectrum scene and comp.sys.sinclair, NESticle and Bloodlust Software, the 3K Space Invaders emulator.
Amiga Shopper issue 1, May 1991, p. 106: public-domain library advertisement listing Spectrum, C64 and ST emulators.
Gary Penn, opinion column, PC Gamer (UK) issue 8, July 1994, p. 39: Spectrum and C64 emulation on the PC and their removal from shareware libraries.
Edge issue 69, March 1999, news, pp. 8–9: UltraHLE’s release on 28 January 1999, its size, its authors’ statements, Beth Llewelyn’s comments, Edge’s verdict; Sony’s suit against Connectix filed on 27 January, the refused restraining order, the $50 price and Roy McDonald’s comment.
PC Zone issue 75, April 1999, pp. 18–19: Nintendo’s statement on UltraHLE, the failed restraining order against Connectix.
PC Zone issue 77, June 1999, p. 32: bleem!’s website traffic and demo downloads; Sony’s suit over the PlayStation BIOS on Dave’s Classics; Sony in court with Connectix.
Edge issue 71, May 1999, news: bleem! beats Connectix to a commercial PC PlayStation emulator; Sony’s action against the host of Dave’s Classics.
Edge issue 86, July 2000, news: bleem!’s announcement of its Dreamcast emulator on 11 May 2000.
Edge issue 72, June 1999, news, “Sony strikes back at Connectix”: the preliminary injunction, its terms, Roy McDonald’s response, and Sony’s failed restraining order against bleem!.
PC Zone issue 78, July 1999, p. 28: the preliminary injunction against Connectix.
APC (Australian Personal Computer), May 2000, emulators feature, “Emulation and the law”, pp. 198–200: the District Court and Ninth Circuit decisions and the court’s words, the case against bleem! and its counterclaims, Sean Kauppinen’s comment, the Australian position, Cloanto’s Amiga Forever and UAE’s Kickstart requirement, Amstrad’s release of the CPC ROMs.
Computer Gaming World issue 203, June 2001, p. 105: Sony’s purchase of the Virtual Game Station.
Computer Gaming World issue 240, July 2004, p. 35: “sued Bleem and Connectix into submission”.
Edge issue 115, October 2002, “The MAME game”: the legal position of emulators and games.
Retro Gamer issue 11, 2004, pp. 47–49: the Super Mario Bros. 3 save-state video.
Sony Computer Entertainment, Inc. v. Connectix Corp., 203 F.3d 596 (9th Cir. 2000), decided 10 February 2000 (public record); summarised with the later purchase of the Virtual Game Station in Wikipedia, “Sony Computer Entertainment, Inc. v. Connectix Corp.” (accessed September 2026) (web, secondary). https://en.wikipedia.org/wiki/Sony_Computer_Entertainment,_Inc._v._Connectix_Corp.
Wikipedia, “Bleem!” (accessed September 2026) (web, secondary): the company’s closure in 2001. https://en.wikipedia.org/wiki/Bleem!