I would like to note that, when speaking about hardware, an emulator is not a simulator. There is a key characteristic that distinguishes an emulator from a simulator. Bluntly speaking, an emulator will mimic the other machine’s hardware in real time. This characteristic allows user interaction within the program running in the emulator.

On the other hand, a simulator does not run in real time, so interaction with a running simulation is not possible. One example is SPICE, a popular circuit simulator. Even though you can specify what components you want in your circuit simulation, and specify how long you want the simulation to run, you are not able to, say, disconnect a component to see what the results are in real time.

There are various reasons why someone would want to use an emulator over the actually physical counterpart. One reason is platform independence. Instead of being forced to buy extra hardware to run a new application, a user can purchase an emulator for that hardware and run it on their current hardware. On example are the numerous PC emulators for the MAC.

Another reason is convenience. Let’s say you have a shiny new PC in your office and you need to connect to an old server using VT100 terminal. You could install an old, bulky VT100 terminal in your office, or you could install a terminal emulator on that machine. Not only would it be easier to install a piece of software over equipment, it would most likely cost less, which is another advantage.

As you might have guessed, an emulator that runs software intended for a console (video game) machine is called a console emulator. But where do these console emulators come from and why are they created? To fully their origin, we need to examine something called the emulation scene.

The emulation scene is a unified collaboration of console gaming enthusiasts from around the world. It consists of students in either software of hardware engineering or general hardware enthusiast or "gurus". The console emulators are written, distributed and supported by the group for hobby and recreational purposes. Overall, this collaboration is responsible for the current flow of console emulators.

The biggest challenge facing the authors of these emulators is the lack of information. Since the manufactures of these console units do not distribute documentation about their hardware, there is exists little or no public documentation to refer to. However, many of the components are off the shelve and their operation can eventually be figured out. One example is the Sega Genesis. Its main CPU is the popular 68000 processor.

However, hacking a unit to figure out how it works is not a simple and quick task. All information on console hardware that is currently known by the emulation scene was obtained through collective hacking and reverse engineering attempts of the units. The Internet has helped speed the process by collaborating efforts worldwide, which is why much of the progress in console emulation has occurred recently.

But why would someone go through all of this trouble? What were the main motivations behind console emulation that drove it to its current state? There are two chief reasons.

The first reason, (laugh if you want,) was that many gamers just wanted to play their favorite console games on the PC. At the time, the idea of being able to play the exact version of a console game on the PC was a fresh, new concept. Many projects started off by an author attempt to get one or two of their favor games to run on the PC. Even though the initial quality of emulation was not nearly as good as it was today, it still pleased many people’s interests.

The second reason was game preservation. There are many classic games from the 80’s that can no longer be bought in stores. Many game enthusiasts who remember playing these games from there past can’t get their hands on a copy. By creating an emulator for these classic systems, along with posting copies of the games themselves on the web essentially keeps the game open to the masses and protects it from fading into oblivion.

It is important to note that console emulation was never intended to be a tool of piracy, which will become important to note later on.

Ok, so these console emulators sound pretty interesting. But, are they legal? Yes, they are, provided that the following rules were obeyed in their development. First of all, no copy protection built into the console unit could have been broken in order to discover functionality. Basically, if something in the design is encrypted, working around the encrypted lockout to discover a functionality is illegal.

Second, the ROM BIOS of the console unit could not of been reversed engineered to learn about the unit’s behavior. A person cannot dismantle the code stored in the ROM BIOS because its code is protected under copyright law.

If either of these two rules were broken during the development of the emulator, the emulator that was creates is illegal. If they were obeyed, then the final product is perfectly legal. Enforcement of these rules by the emulator authors is not enforced, but it is assumed that they are not broken. Older console units either have no lockouts or a ROM BIOS with no hidden secret such that would require someone to break these rules to find a hidden functionality.

Currently, there are only two legal cases that have emerged against emulator authors. The emulators in question are bleem! and Virtual Game Station (VGS). Both emulators emulate the Sony Playstation(c) game console and are available commercially. Sony has tried repeatedly to block the shipments of both emulators in court, but the courts have ruled in favor of the emulator authors each time.

There is another side to the legal issues. Generally speaking, how do you copy a game from a cartridge to a computer for use on an emulator? As we will see in the next section, the process to achieve this feat is not complex, the legal the issues behind it, however, are.

As you might of imagined, if someone wants to play an exact copy of their favor game on the computer, then first need to dump the game from a cartridge to the computer.

Though-out the history of console gaming, the most popular medium to store and distribute games has been the game cartridge. A game cartridge (cart) is nothing more then preprogrammed ROM chips with plastic housing. It is very reliable, and it can withstand a much harsher beating then, say, a floppy diskette.

In order to run the program stored in the cartridge onto an emulator, one would need to dump the contents from the cartridge onto disk. Many people have created homemade units known as ROM readers to read and dump the data from these cartridges. The net result is known as a ROM image.

The concept behind a ROM reader is simple. I will use the diagram at the right to illustrate. (Courtesy of J. Rizzo.) Using a binary counter, you begin at zero and address byte 0000 in the ROM’s memory. You then read in the byte to disk and increment the counter to 1. You repeat this process until the contents of memory have been fully explored. To make matters easier, one could use the pins on the cartridge itself instead of the pins on the ROM chip to read-in the data.

If you are not cleaver enough to design your own ROM reader or a just don’t feel like making one, commercial ROM "back-up" devices can be purchased. These devices are designed to be mounted on the cartridge port of your console unit. Not only can they dump the data of a cartridge onto disk, they can also load and run copied games from the device’s rewrittable ROM as well. Though the devices are marketed as a backup device incase your game cartridge dies, they were intended for piracy purposes only due to their ability to run any ROM image. In fact, Nintendo, a huge console maker, successfully filed suit against some of these manufactures.

Since everyone in the emulation scene does not have a ROM reader for whatever reason, the distribution of ROM images has become common place. The general consensus of ROM image distribution is that it is legal as long as you own a copy of the game being retrieved. However, proof of ownership is never checked, so everyone is expected to operate on the "honor system." As we will see in the next section, this opens up a complex debate.

Are images legal? The law is not unclear on this matter. Under US law, creating a backup of software that you own is legal. Thus, creating a ROM image of a game that you own is legal for back-up purposes. In fact, it is legal to run the copied software on an emulator. The only pitfall is that only one copy of the game can be active at a time, because the other copy is intended for archaic purposes. This means that your physical counterpart cannot be in use while you are using the copy on emulator.

However, distributing or obtaining unauthorized copies of a ROM image is illegal. A cartridge that I buy from the store is considered an authorized copy. If I were to copy a cartridge that I own, the copy I now posses is not authorized by the manufacture, but it is perfectly legal to have. It would be illegal to distribute that unauthorized copy to others.

The true nature of the law on ROM images is not fully known, mainly because the matter was never fought in court. It does not appear that any legal battles will be fought over it anytime soon. Many ROM sites, who distribute unauthorized copies of ROM images, have been shutdown after being threaten with legal action. But new ones come and go every day, so it’s hard, if not impossible, to crack down on ROM image distribution on the Internet. Until a lawsuit is challenge, no one will know for sure on how the law stands on the issue of ROM images.

The spread of console emulation has impacted everyone involved, weather directly or indirectly. In this section, we will example the impact on three fronts: the software manufactures, the console manufactures, and the emulation scene itself.

The reaction from those that write the software used by the emulator authors is a little complex to understand. For starters, many software companies that wrote the programs for many of the classic game from the 80’s have said that they actually like emulation in the sense that it helps prevent their classic games from fading into oblivion. Some have even released their old games as "freeware."

However, because of the legal issues surrounding ROM images, the vast majority does not favor console emulation for cartridge-based systems. However, for CD-ROM based units, they have no problem with console emulation. Weather console emulation will help increase sales of their software for these CD-ROM based units is known.

In order to understand how the spread of console emulation has affected the emulation scene itself, it is helpful to think about its evolution in three time periods: the golden age, the middle age and the new age.

The golden age of console emulation spanned from the early 90’s to mid 1996. The console emulators that were written were for earlier console system, such as the Atari 2600, the NES and the C64. ROM image distribution was viewed ok because they were for old and outdated systems, so the companies that wrote the games should not be affected. During this time, Gameboy, SNES and Genesis emulators were proposed.

The middle age of console emulation spanned from mid 1996 to December 1998. Emulators for various 16-bit consoles, such as the SNES and Genesis, were introduced. Playstation and N64 emulators were also proposed during this time. (Some functional Playstation emulators were released.) The view on ROM image distribution changed and was viewed ok as long as they were being distributed amongst owners.

It was also during this time that people begin to view console emulation as a tool of pirating. That came after main respect console site being to "mass market" emulation by appealing to a broader audience, which in turn drew in a lot of negative attention. This negative attention has given console emulation the black eye of being a tool for piracy.

The new age of console emulation spans from January of 1999 to the present. The mass marketing of console emulation becomes apparent with the release of the first two commercial console emulators: bleem! and Virtual Game Station (VGS). Both were Playstation emulators, which could read and execute the program written onto a Playstation-format CD directly.

The release of UltraHLE, the first fully function Nintendo64 (N64) emulator, divides the emulation scene. Up until this time, all the emulators were for console systems that no longer enjoyed a strong grip in the market. This fact made it easier for non-believers in ROM image distribution to accept it because no one was being harmed. (The Playstation console is excluded because their CDs can be read directly by the PC.) However, the N64 still had a strong grip in the market and the release of this emulator would only reinforce the notion that console emulation was a tool of piracy.

The reactions of the "Big three" console manufactures, (SONY, Nintendo and SEGA) on console emulation have been mixed.

Nintendo originally tolerated emulation. The most they did against emulation was order web sites that distributed ROM images to shut down. However, with the release of UltraHLE, the first fully functional Nintendo64 emulator, prompted change in their policies.

They mentioned that they would be suing the authors of UltraHLE, but they have failed to even file charges against them. Nintendo’s claim was that the authors of UltraHLE had to of broken some lokcout inside the N64, but the authors have denied this claim. Currently, Nintendo’s stance is completely anti-emulation. In fact, their web site has a section of misleading information concern the legal issues of console emulation.

Sony too originally had no argument against a console emulator of their Playstation console until the release of the two retail Playstation emulators, VGS and bleem!. Sony has made repeated attempts to sue the authors of bleem! and VGS, but have failed at each attempt. Sony has no plans in accepting console emulation at all because it will interfere with their marketing plan of their new Playstation 2 console. Bluntly speaking, they want to lure people away from thinking that the PC is the "ultimate" game platform of the future and have them focus their new Playstation 2 console instead. Supporting console emulation will only hurt their objective.

SEGA, on the other hand, has quietly accepted emulation. In fact, SEGA is believed to have bought the rights to Kgen, (a popular Genesis emulator,) and sold some of their SEGA Genesis games that ran off that emulator. There is even talk about a Genesis emulator for the new DreamCast.

Since the dominance that SEGA once held in the market in the early 90’s has been lost, the spread of emulation only helps SEGA in the long run. Weather good or bad, console emulation only helps them by promoting their next generation console system, the Dreamcast, by exposing people to their successful past line of games.

One thing I would like to note is that Nintendo has been fighting off piracy of their cartridges for years, long before the emulation scene was established. In fact, some of their cartridges have copy protection circuitry. However, hackers have successfully gotten around the lockouts and dumped the cartridge’s data. There have been no reported cases where a manufacture has tried to encrypt the data within a game cartridge. Only the ROM chips inside arcade machines have been known to be encrypted some manor.

As we have seen, the people behind the current spread of console emulation are those in the emulation scene. The emulation scene consists of students and video game "gurus" from around the world. It is important to remember that console emulation was never intended to be used as a tool of piracy, even though software pirates have used it for negative purposes.

The legal issues surround console emulation are still in debate. Emulators are legal, assuming no laws were broken in creating them. The legal issues on console emulation have been fought in court in favor of the emulator authors. The legal issues that surround ROM images appear to be legal, but only to an extent. How the law views ROM images is currently unknown since the matter has not been fought in court.

The impact of console emulation has been mixed. Software manufactures only favor the emulation of CD-ROM based consoles. As for the console manufactures themselves, Sony and Nintendo are boldly against emulation and have threatened or filed suit against the authors of emulators. Sega on the other hand, has quietly accepted it and even sold products using emulation.

As for the impact on the emulation scene itself, the widespread popularity of emulation has only crippled it’s image, branding it with the label of being a tool of piracy to some.

Controversial Time Magazine article on emulation, entitled Video Games Get Trashed
http://www.pathfinder.com/time/magazine/articles/0,3266,21056,00.html