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Emulation HQ .: EmuHQ Content .: Series: Emulation: Right or Wrong? .: Emulation: Right or Wrong? Module 1 Part 3: by The Scribe
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Emulation: Right or Wrong? Module 1 Part 3: by The Scribe

Emulation:  Right or Wrong?
aka "The EmuFAQ"
version 1.033

copyright (c) 1999 Sam Pettus (aka "the Scribe"), all rights reserved

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Module One:  The Emulator
Part 3 - Releasing an Emulator


     28 January 1999 marked a significant event in the world of videogame emulation.  It was on that day that a team of two hackers, known only by the aliases of Epsilion and RealityMan, released UltraHLE - the world's first working emulator for the Nintendo 64 videogame console.  Many had tried over the previous year to devise an emulator for that system and failed, whereas the one project that seemed to be making significant progress (Project Unreality) was terminated due to threats of legal action.  Both Epsilion and RealityMan had been quietly working on their own emulator during this time and decided that a new approach was needed.  Instead of starting with the console's base functions and working upwards, they started with its high-level functions and worked down (hence the name UltraHLE - Ultra High Level Emulator).  They also decided, in light of Nintendo's public attitude with regards to emulation, that they would not tell anyone about their project until they felt it was ready, and then make it available to as many people as they could in the shortest amount of time.
     The sudden and unexpected release of a working N64 emulator caught the emulation and videogame communities completely by surprise.  A blindsided Nintendo quickly rushed to shut down the UltraHLE website and threatened prosecution against the authors and anyone carrying or supporting UltraHLE, but it was too late.  Epsilion and RealityMan's release tactics had ensured that UltraHLE would be spread far and wide given the nature of the Internet, and a helpless Nintendo could do little but watch as UltraHLE popped up on one site after another in quick and rapid succession.  N64 cart dumps had already been available on the backwater sites for over a year, and now patrons of the "warez scene" had something with which to play their bootleg videogames.  UltraHLE was by no means perfect, and only worked with about one-third of the "ROMs" in existence at the time, but the fact that it worked at all what was upset Nintendo the most.
     Nintendo's next reaction was what those familiar with its history might expect:  it continued to threaten legal action against anyone who supported UltraHLE, and filed suit against its authors claiming that the emulator was an infringing work that promoted software piracy.  The threats were pure bluff and many sites called them on it - those that weren't carrying any
bootleg N64 "ROMz," that is.  As for the suit, it is still pending, and the resultant legal pressures coupled with the instant popularity of UltraHLE among the software pirates forced the premature retirement of RealityMan from the emulation scene.  Although the construction of UltraHLE remains a closely guarded secret even to this day, Epsilion and RealityMan contend
that it was an 100% reverse-engineered software-based emulator.  In the meantime, Nintendo's legendary intimidation tactics continue to be employed against anybody who carries UltraHLE, but the sad truth is that UltraHLE continues to be freely available and can be downloaded by anybody with the will to find it.  As a result, many feel that Nintendo's ire towards the
emulation community will fall upon emulator developers as well as "ROM" distributors from now on.
     This incident caused some serious soul-searching among the emulation community, as well as many a comment from the videogame industry.  Most were of the opinion that UltraHLE should not be supported because it was designed to emulate a product that was very much alive and kicking.  The release of UltraHLE implied that the end-days of the N64 were near, and nobody really believed that.  On the other hand, there were those who argued that they should not discriminate against a legal emulator regardless of the status of the original system, and these were the folks who continued to carry UltraHLE on their web sites while the rest refused.  The videogame community was equally split, with many expressing admiration for the programmers and their accomplishment and many calling for their prompt prosecution.  The debate seems to have died down after RealityMan announced his retirement from the emulation scene, and not long after UltraHLE reappeared on just
about every single major emulation site.  Those who had fought its support before now felt justified in carrying it after Nintendo's failed attempts to stop it; furthermore, they noted that there were several public-domain "ROMs" available for it just as there were for other videogame emulators.  The availability of a legally downloadable software base for the emulator,
however limited and incompatible that might be, seemed enough justification enough to many minds for supporting this remarkable program.  As an afterthought, it is ironic to note that Nintendo announced plans to release a new videogame console (the N2000, codenamed Dolphin) not long after the release of UltraHLE, so perhaps those who feared the console's impending obsolesence may have been right after all.
     In previous discussions, we have seen that emulation is a valid use for a computer system; furthermore, that an unlicensed emulator is possible once the intellectual property concerns are properly addressed.  The time has now come for the next important step:  the release of an unlicensed emulator.


     In this and future discussions, I will refrain from discussing pure hardware-based emulators, as well as the more common varieties of hardware-software combinations.  Pure hardware emulators are almost always produced by original vendors or other companies under license to the original vendor.  Remember, the ability of the Sega Genesis/MegaDrive to emulate a Sega Master System via VDP mode 4 was due to Sega itself and installed as a desire to support its customer base for the older platform.  Sony is taking the same position with regards to the announced release of its newer Playstation 2 console; they are planning the inclusion of a special I/O chip that will permit the playing of older Playstation titles on the new system.  This is a practice that is universally accepted within the industry; furthermore, hardware-based emulators are quite profitable to the original vendor due to the proprietary nature of such.  It would be almost impossible to build a pure hardware emulator without the consent of the original vendor, and the laws are quite clear with regards to the illegality of unlicensed clone products.  Just ask all of the folks who tried to manufacture unlicensed clones of the NES and see where it landed them.
     A hardware-software combination is a different animal altogether, and their very nature tends to blur the legal lines somewhat.  For example, Commodore's cross-licensing agreements with various PC clone manufacturers gave them solid legal ground upon which to base their PC Bridgeboard product for their Amiga computer systems.  The same could be said of A-Max, as its only vendor-produced requirement was the original Macintosh BIOS which had to be obtained through legal means, and the courts ruled that this was acceptable.  Jump forward in time to the present, where hardware-software combos have taken a new twist - the requirement of a BIOS dump, which is nothing more than a software image of the computer code contained within the BIOS of the original system.  Remember the A-Max bootleg?  It's the same thing, but almost a decade later.  I will reserve the discussion of the legality of this practice for another time, but will note in passing that such emulators have become widespread.  For example, Cloanto of Italy sells a package desgined expressly for users of the WinUAE Amiga emulator.  It provides a legal copy of the AmigaDOS software, along with a legally licensed copy of the Amiga Kickstart ROM (the system BIOS, in other words).  True hardware-software combos are becoming more rare with each passing day due to the incredible advances in computer processing capability, and the time will no doubt come when their existence will be limited to providing emulation for highly specialized niche systems that have a minimal impact at best upon the computer industry.


     It goes without saying that a pure software-based emulator should be comprised entirely of reverse-engineered code before you release it to the world.  This neatly avoids any legal claim that the original vendor can mount against you in this regard, such as what happened between Intel and AMD over the Am80386.  The courts have ruled time and again that reverse engineering does not void copyright protection, as it does not replicate the original's "defining algorithims."  A program written entirely in 100% reverse-engineered code is therefore legal, so it stands to reason that any emulator that is 100% reverse-engineered should also be legal.  This is the stance that the makers of the bleem! Playstation emulator are pursuing as part of their defense in their current legal dispute with Sony, and there is little doubt within the minds of almost everybody within the computer and videogame industries that Sony will lose that particular battle based on based on existing legal precedent.  If so, then the legality of a 100% reverse-engineered pure software-based emulator will be established once and for all.  Another example you might consider is Steve Snake's KGen emulator for the Sega Genesis/MegaDrive, which was also a 100% reverse-engineered product It proved to be such a good program that Sega eventually licensed the source code from the author for use in its commercially released Sega Smash Pack.  Talk about coming full circle!
     As a final nod to the issue of of reverse engineering, let me share something with you from a leading major industrial organization with whom I have dealt in an indirect way for many years.  One of the chief trade organizations in the electromechanical industry is the Institute of Electrical and Electronics Engineers (IEEE).  You normally hear about them
whenever there is a dispute about specifications for electrical or mechanical components; they are the industry's means of regulating itself.  Here are some significant excerpts from their official policy statement regarding the concept and practice of reverse engineering which you might find interesting:

     ...We also believe that the high intellectual content of a computer product and competition are enhanced when
     computer products developed by one vendor are capable of operating with computer products developed
     by another vendor.  This compatability promotes the development of interoperable products by independent and
     competing vendors and, therefore, promotes enhanced value to the vendee at a competitive price....

     We further believe that lawful reverse engineering of computer programs is fundamental to the development
     of programs and software-related technology....  We further believe that lawful reading, analysis, or disassembly of
     machine language is a reverse engineering technique by which an engineer can reconstruct the ideas of a computer

     Accordingly, an engineer having the right to use a copy of a computer program should be entitled, without the
     authorization of the author, to observe, study, and test the functioning of the program, in order to determine the ideas
     that underlie the program, if it is accomplished while performing any of the acts of reading, displaying, running,
     transmitting, receiving, or storing the program or other lawful acts involving the program that the engineer is entitled to

     We support the fair use rulings in the recent Appellate Court decisions in the Ninth and Federal Circuit, in Sega
     Enterprises vs. Accolade, 977F.2d 1510 (9th Cir. 1992) and Nintendo vs. Atari, 975F.2d 832 (Fed Cir. 1992)
     pertaining to dissasembly of computer code.

Pretty strong stuff, isn't it?  And from one of the "big guns," too.  These are the people who tell companies like Nintendo exactly how they can build their systems in such a way as to be considered safe for its users.  The IEEE would not issue a policy statement with regards to the legality of reverse engineering and its underlying requirements unless they were absolutely sure of their facts.  Emulator developers should take this to heart whenever an original vendor begins making broad claims of patent and copyright violation against them.  Such claims are frequently unfounded, and are almost always proven so when the issue is pressed in the courts.


     Finally, the day arrives when you plan to unveil your emulator.  Whether you are a commercial company with considerable time and resources invested in your product, or you're just an extremely gifted hacker like the one described earlier, the time has come to make your creation known to world.  What happens next?  Well, that depends on two things:  who originally vended the system you are emulating, and how old that technology might be.
     There has been a growing acceptance of emulation within the computer and videogame industry; however, it is not yet universal.  Nintendo's attitude is well known and is embodied in their official emulation FAQ:

     The UltraHLE [sic] is illegal.  The N64 emulator infringes Nintendo's intellectual property rights, including copyrights,
     and circumvents Nintendo's anti-piracy security system.

While you may not agree with their stance and their contentions may not be provable, it nevertheless highlights one extreme of the scale that original vendors use to measure emulation.  A completely different approach is taken by Hasbro, now the owner of Nintendo's longtime competitor Atari, who recently released all rights for the now-defunct Atari Jaguar videogame system into the public domain:

     We realize there is a passionate audience of diehard Atari fans who want to keep the Jaguar system alive, and we don't
     want to prevent them from doing that.  We will not interfere with the efforts of software developers to create software
     for the Jaguar system.

These are the two extremes you will have to face when deciding how the vendor will react to the release of your unlicensed emulator.  Each company choses to respond in a different way for different systems at any given time, so attempting to predict their behavior is not always successful.
     The other item to consider is the age of the technology you are emulating.  Has the system been dead and gone for several years, or its it just on the verge of expiring?  Or perhaps, as was the case with UltraHLE, the system you wish to emulate is still economically viable.  What then?  Before you answer that question, try looking at the issue from the vendor's perspective, and Nintendo's emulation policy statement makes an excellent point in this regard.

     Copyrights and trademarks of games are corporate assets.  If these vintage titles are available far and wide, it
     undermines the value of this intellectual property and adversely affects the right owner.  In addition, the assumption that
     the games involved are vintage or nostalgia games is incorrect.  In fact, there are now more and more programs
     available that emulate current game systems such as Game Boy and the Nintendo 64.

If you release an emulator for a product that it still on the market, you are presenting yourself as a direct threat to that product's market share.  Original vendors, like most companies, try to maximize sales in order to achieve maximum profit at minimum cost.  They only have so much time to sell that system before something new comes along or a competitor releases a better or cheaper product; after all, most computer systems have an fairly short shelf life due to rapidly advancing technology.  As Moore's Law puts it, processing power doubles every eighteen months.  Your emulator could cut in on their best market window - not very much, perhaps, but enough to make a difference on the balance sheets or come tax time.  Do you think they relish this thought? Not at all.  Vendors of systems that have long since gone off the market or are on the verge of dying anyway usually don't complain about emulation, but it's the "live" systems that pose the biggest risk to emulate.  An excellent example of this comes from the personal computer world, where Readysoft vended a commercial emulator for a "live" computer - in this case the Apple Macintosh.  Apple promply sued, and nobody who observed that situation was in any doubt as to Apple's real motivations.  A-Max directly threatened Apple's revenue stream on a current product - in this case, the Macintosh computer as it existed at the time (the Mac Classic, as it is referred to nowdays).
     It may interest you to know that the official IDSA policy statement with regards to emulation states the following with regards to their intended purpose:

     ...most emulators that are freely available today are merely software emulators that have no role in the creation of
     properly licensed videogames and therefore have the exclusive purpose of infringing copyrights and are unambiguously

This may be true if you are looking at the issue from a pure videogame standpoint; however, freeware emulation covers considerably more territory than just videogames.  It is the popularity of videogames that causes the issues they raise to be brought to the fore ahead of all others.  In addition, certain commercial videogame companies actually encourage emulation with regard to their products (Atari, for example); thus the IDSA cannot prove its claim of emulation being "unambiguously illegal."  One such example is well-known in the emulation community.  Steve Snake's KGen was available as a freeware product long before it became "legitimized" by Sega with the Sega Smash Pack.  As someone who aided in its development, albeit in a small way, I can say without hesitation that it would never have been licensed had it not proven itself in the eyes of the emulation community first.  That is what got Sega's attention, and the rest, as they say, is history.  The IDSA is in error with their policy statement in this regard and should amend it to read "many videogame emulators...are for the most part illegal."  Not that they will - they have to say what they say the way they say it in order to make the strongest case possible for their beliefs - but such a change would make them seem less pretentious.


     There are three primary attacks by an original vendor on the developer of an unlicensed emulator.  It is not surprising that each falls under the three major categories of intellectual property protection:

        Patent violation:  Emulation permits the bypassing of any antipiracy protection measures and other such proprietary
        vendor processes internal to the hardware and original software of the system.  This represents a direct threat to the
        intellectual property rights of the original vendor.

        Copyright infringement:  Emulation promotes software piracy because users are no longer requried to buy the
        original system, and as such represents a clear and present threat to the original vendor's profit margin.  It is also a
        given that users may no longer be required to obtain the system's software in its original commercial format.
        Since vendors traditionally reap the most profit from software sales, this further impacts potential revenue.

        Trademark concerns.  It is a fact that emulators are never as good as the actual hardware.  This could contribute
        to a detrimental mindset against the original vendor, as an emulator does not accurately replicate the experience of using
        the original system.  As such, emulation poses a direct threat to both the corporate image and quality control of the
        original vendor and its affiliated licensees.

So how does an emulator author protect themselves against legal action by the original vendor and/or its licensees?  Here are some of the primary defenses upon which an independent developer could build when being sued over the release of an unlicensed emulator:

        Patent violation. Reverse engineering is a legally recognized process whereby the function of original vendor
        equipment can be reproduced without using proprietary vendor constructs and designs (IBM vs. Phoenix Technologies,
        1982?).  As long as an emulator successfully duplicates the workings of the actual system but does not contain any of the
        vendor's proprietary computer code (or unlicensed custom hardware), then the emulator is a legal product (Intel vs.
        AMD, 1991).  The legality of emulation has already been established in the courts (Apple vs. Readysoft, 1989).
        Most emulator authors contend and can prove that they used only publicly available information (press releases, reviews,
        close obsevation of the actual system, etc.) in developing their emulator.  Those who are forced to use a vendor-specific
        part or process (like a vendor BIOS) will almost always devise a means whereby the user must legally obtain said items
        themselves in order to get such an emulator to function properly.  Once it is established that the emulator is indeed a
        legal  product, then any claims of intellectual property infringement are unsubstantiated.

        Nintendo and certain other vendors like to counter this argument with one of their own:  that their so-called antipiracy
        security systems qualify as a vendor-specific process.  In fact, the primary purpose of most videogame antipiracy
        systems is twofold:  first, to prevent titles developed in one market from being used in another; second, to prevent
        production of unlicensed titles by independent developers.  Unlicensed duplication is in fact a minor issue at best.  That
        is why Atari had such a hard time in the courts - its 2600 console had no such system and therefore did not qualify for
        patent protection (no unique parts).  That is why Japanese Playstation games won't work on American-vended consoles
        and vice-versa without special modifications.  That is why the first Atari conversions for the NES did not work until they
        found a way to emulate the system's 10NES lockout codes.  The preferred way to dodge the "unlicensed" bullet is to
        design your emulator in such a way as to avoid or ignore any antipiracy systems that the system's software might engage.
        Such is difficult, but not impossible.  The best way to dodge the "market" bullet is to design your emulator so it will work
        only with those titles released for a specific market.  Unfortunately, such dodges are the exception rather than the rule
        because of the desire on the part of many emulator authors to support all of a system's functions and software base
        regardless of purpose or market origin.  In addition, the Digital Millenium Act makes it illegal to bypass the security
        system of a computer-based system, and it is unclear at this time whether or not any antipiracy systems for videogame
        consoles would qualify as a bonafide security system under the terms of that law.  Therefore, the legality of an
        unlicensed emulator for computer-based systems made since the passage of the Digital Millenium Act remains unclear at
        this time.  In fact, due to the long-lived nature of copyrights, such protection might be sought retroactively for older
        systems - in which case there are few options available for defense other than market unviability of the original.

        Copyright infringement. The impact of sales of an unlicensed product vs. sales of an licensed product is
        minimal at best (Nintendo vs. Galoob, 1990).  Emulators are usually released well into the lifetime of a system, when
        the market for such a product is diminishiing, and are almost always a good indication that the original system has
        become dated or is nearing obsolescence.  Also, emulation tends to support the formats used by software pirates
        because these formats are the same used by developers who need to create "intermediate copies" of existing titles for
        development purposes (Sega vs. Accolade, 1992).  This affilation is often circumstantial, since software pirates can get
        access to the same kind of dumping and/or duplication hardware that a legitimate developer would.  Such alternate
        formats are usually easier for an emulator developer to work with and support due to their software-based nature.
        While we're on the subject, let's not forget that the legality of emulating or reverse-engineering proprietary vendor
        functions within the original system has been established by case law (Nintendo vs. Atari, 1992), so long as they
        do not contain any "unnecessary elements" with regards to performance.

        If a vendor choses to use a delivery system that is susceptible to software piracy, then they have opened
        themselves up to same.  It is given that there will always be software piracy and that a small portion of sales will be lost
        to same.  Most system vendors accept this, adjusting the price of their product upward somewhat in anticpation of
        expected losses, and adopt a two-pronged attack on any infringers:  they modify their delivery systems in such a way as
        to discourage the manufacture of infringing copies of their software (antipiracy systems and copy-protection schemes),
        and they aggressively prosecute any and all perceived cases of intellectual property violation.  This is why vendors of
        videogame consoles using the CD-ROM delivery format (Sony Playstation, et. al.) have been more prone to software
        piracy than vendors who choose a more difficult delivery process to successfully replicate, such as ROM-based game
        cartridges (Nintendo N64).

        Nintendo has a unique argument in this regard that they recently exercised against Episilon and RealityMan, the authors
        of UltraHLE.  Borrowing from their own past experiences with Atari/Tengen, they claimed that UltraHLE was "a
        product designed solely to play infringing copies of copyrighted works developed by Nintendo and its third-party
        licensees."  The wording comes straight from case law, where any unauthorized reproduction of a copyrighted
        work is said to be "an infringement of the copyright;" i.e. an infringing copy.  (MAI vs. Peak, 1993).  The courts
        have determined that the burden of proof with regards to copyright infringement is on the vendor, but the vendor only
        has to show reasonable grounds for such infringement - not proof beyond a shadow of a doubt.  Even so, many within
        the emulation community and the videogame industry as a whole feel that Nintendo is behaving rather badly in this
        regard and that their contentions will not hold up in court should the case ever come to trial.  To quote George
        Broussard of 3DRealms, "Nintendo should be hiring these guys instead of suing them."  It will be interesting to see if
        Nintendo's claims concerning the function and purpose of UltraHLE are deemed to be valid once actual legal
        proceedings commence.  They certainly believe so, and can back up their beliefs with case law, but it will be up to the
        courts to decide whether or not belief is the same as fact.

        Trademark concerns.  Any negative impact against the original vendor as a result of a sub-par emulation "experience"
        can easily be remedied with improvements to the emulator and/or beefed-up hardware/software support on the user's
        part.  The user almost always has the option to go out and buy the original system if they are dissatisfied with the
        emulator's performance.  Original vendors do not want an independent product to infringe upon their product's "gaming
        experience," so they will do anything they can to ensure that their customer base remains locked-in to their
        product (Atari vs Nintendo, 1988; Nintendo vs. Galoob, 1990).  The courts have not always agreed that such
        monopolistic practices are legal (New York vs. Nintendo, 1991; AVE vs. Nintendo, 1991); however, they have no
        objection to an original vendor opposing an unlicensed product (Nintendo vs. Atari, 1992).   This is how Nintendo
        can remain so violently opposed to emulation and get away with it - they perceive it as a viable threat to their corporate
        assets.  To quote Nintendo's opinion from their emulation policy statement, "Emulators promote piracy. That's like asking
        why doesn't Nintendo legitimize piracy.  It doesn't make any business sense.  It's that simple and not open to debate."
        No, it's not that simple, and it is indeed open to debate, as anyone who researches the issue will discover.  One should
        consider Nintendo's real motivations on the subject before passing judgement on this issue.


     So why do some original vendors get so upset about emulation?  Well, look at it from their point-of-view.  Somebody wrote the code to that game you're playing on your emulator.  A mid-sized company paid them for it or the license to it, and then a big company bought the rights to vend it.  On top of that, system vendors have their own financial arrangements when it
comes to developing and/or porting software to and from their proprietary hardware.  That software is designed to be specifically used with the original vendor's system.  With regards to that system, somebody spent a lot of money researching and designing it.  They may have contracted others to do it for them, or they may have made it themselves.  It costs money for
research and development, intellectual property protection, promotion and advertising, manufacturing, and so on.  The only way they are to make that money back is to sell their product at a profit - which means they have to sell lots of units and lots of software for that system in order to get a return on their investment.  Paid ... bought ... financial arrangements ... money ... contracted ... profit ... sell ... investment - do you see the common theme?  Now do you understand why a firm like Nintendo screams bloody murder whenver somebody comes along and emulates a system that has yet to even show signs of finishing its market run?  Do they get upset?  You bet!  In their eyes, emulation is an infringement not only of their intellectual property rights but also a direct threat to the profitability of their corporate assets - however small in truth that may be.  As long as said assets remain viable as far as the markets are concerned, as long as such threats exist, and as long as there are legal means to eliminate them, then you can expect them to defend their sources of revenue by any means necessary.


     So what's the practical upshot of everything we have discussed?  If you are going to independently develop and then release an unlicensed emulator, then you need to keep the following general principles in mind.  Releasing an unlicensed emulator is deemed acceptable so long as:

     -  it does not employ in its design any or all parts of the actual patented or copyrighted code used in the design of
        the actual hardware that it is emulating.

     This includes but is not limited to the BIOS, any other on-board integrated circuts (proprietary or otherwise), and any
     system-specific software designed to ensure the operation of the actual hardware (such as its operating system).  This is
     why certain emulators require an interface to the actual system's BIOS code - they can't include it due to copyright
     restrictions.  A-Max was one of the early examples of such an emulator - you had to go out and buy the real Mac BIOS
     and install in its oversized dongle before the thing would work.

     -  it does not violate the patents, copyrights, and trademarks of the original vendor and/or its licensees concerning
        the original system itself or any accessories designed for use with it.

     Here is where things get dicey for emulator authors.  If a specific piece of hardware or software within the console has
     been patented (or has been registered for patent protection) then you have no legal right to duplicate it without the
     consent of the patentholder.  That's the old "intellectual property" argument rearing its head again.  You do have the full
     legal right to reverse-engineer them and include the reverse-engineered code within your emulator, so long as the resultant
     code cannot be construed as being based upon, derived directly from, or duplicated in any other way from the original.
     Ever wonder from where all those public-domain processor cores come that emulator authors are so fond of using?
     This is the reason why.  Developers reverse-engineer those old processors and then post the reverse-engineered code as
     public domain source.  It saves development time and neatly sidesteps the illegality of using dumped original code within
     anyone's program.

     -  it does not include any materials which would infringe upon the intellectual property rights of the original
        vendor or its licensees.

     In short, that means you cannot package your emulator with any of those "ROMs" or "ROM packs" that seem to be so
     popular ("ROM" is an emulation slang term for a piece of old computer software; I will deal more on this subject later).
     They almost always contain one or more programs that were commercially released in an earlier life and as such are
     protected by copyright.  An excellent example of such an emulator is MAME, the Multiple Arcade Machine Emulator
     originally authored by Nicola Salmoria, which is one of the most popular programs within the emulation community.  Its
     distribution agreement states up front that anybody who distributes MAME may not include it within a package containing
     any or all of the arcade "ROMs" that it supports, nor may they include it as part of a arcade "ROM" compilation sold for
     profit (like certain CD-ROMs you see offered for sale by the "warez" sites).  SNEmul is an example of an videogame
     console emulator that also conforms to this principle.  It is distributed with a public domain program in "ROM" format that
     demonstrates this SNES emulator's abilibity to correctly replicate the original console's Mode 7 graphics.  Such a "ROM"
     is not considered to be copyright infringement no matter how you choose to interpret the law.

     -  it does not emulate a computer system that is still economically viable.

     Everybody agrees that Episilon and RealityMan were crazy to release UltraHLE when the original N64 console was still
     very much alive and kicking.  To quote Kenn Hoekstra of Raven Software, "...making an emulator to hand out free games
     for a system that STILL HAS A VIABLE MARKET SHARE is just SUICIDE!  The guys who did it are dumb, in my
     opinion, and should be prosecuted....  How anybody can be shocked or surprised or appalled by this is beyond me...."
     The only real question here is what one means by economically viable.  Does that mean that you wait until the original
     vendor announces plans for a new system, or do you wait until slumping sales hit a certain level, or until the original
     vendor announces that they will soon cease production of the system, or (as certain vendors would have it) until such time
     as the original vendor deigns to grant an expensive license for a product that they intend to sell under their own label?
     There is currently no defined point at which the release of an unlicensed emulator is acceptable, and perhaps it is time
     for the emulation community to better police themselves in this regard.


     Up to this point, we've talked about the basis for emulation.  We've talked about developing an emulator.  We've just finished talking about releasing an emulator.  So what conclusion can we draw about emulation in general?  Apply Occam's Razor and draw the obvious one.  As KGen author Steve Snake recently noted in an Internet message board posting, "Emulation is legal.  It's that simple and not open to debate."
     Companies like Nintendo and Sony can no more stop emulation than King Canute could order back the tide.  It is legal for original vendors to develop their own emulators.  It is legal for an independent developer to make their own emulator, provided it does not violate the original vendor's intellectual property rights.  It is legal for an independent developer to release such an emulator without the original vendor's approval, but it is not generally acceptable to do so until such time as the system being emulated is no longer economically viable.  The only real issue involved here is the actual timing of the release of an unlicensed emulator, and that is the one upon which both the original vendors and the emulation community will have come to terms sooner or later.
     We have now come to the end of the various discussions with regards to the legality of emulation.  You should now know what is involved in developing, releasing, and possibly defending an independently developed unlicensed emulator.  Now come one of the biggest issues of all, and it represents (as the British would say) a "sticky wicket" indeed:  "How do I support an emulator?"  That will comprise our next big area of discussion.


1. Why is hardware-based emulation not considered to be a problem?

2. What particular issues do developers of emulators involving hardware-software combinations have to consider?

3. What is the best means of development in order to produce a legal unlicensed software-based emulator?  Name two
    examples of such a product from the text or provide valid ones of your own.  What does the IEEE have to say about this
    development practice?

4. What are two items of concern that independent developers must consider before releasing an unlicensed emulator?

5. What are the three primary arguments that vendors use whenever they sue the developers of an unlicensed emulator?  What
    charges can you derive from those arguments?

6. How can an emulator developer defend themselves against charges of intellectual property infringement by the original

7. What is the truth behind "antipiracy security systems" in their current form?  What are some ways to deal with this issue?
    Why do some emulator developers choose to ignore the problem in their products?

8. What does the release of an emulator usually indicate with regards to the original system?  Why would this upset the original

9. Which is easier for a videogame emulator developer to work with - program code within the original hardware or dumped
    program code?  Why?  Under what conditions is dumping the program code a valid practice?

10. What is the software industry's general impression with regards to the impact of software piracy on vended software
      sales?  How does this affect the choice of delivery systems for a videogame vendor?  How does this impact upon the
      release of an emulator?

11. What is Nintendo's latest argument with regards to emulation and their intellectual property rights?  What is the basis for
      this argument?  Do you feel their contention is valid?  Why or why not?

12. What was the chief mistake committed by Epsilon and RealityMan concerning the release of UltraHLE?  When is the right
      time for a developer to release an unlicensed emulator?  Why?

13. What causes certain vendors to become concerned whenever an emulator is released for one or more of their systems?

14. What are the four main principles to remember before an independent developer releases an unlicensed emulator?

15. Is emulation legal?  Why or why not?


1. If it is legal to design and then release an emulator, then is it legal to provide copies of the commercial software originally
    designed for use with the system being emulated?

2. Is it legal to dump a BIOS image in order to avoid having to create an emulator that would otherwise be a hardware-
    software combination in design?

3. What is a "ROM?"  Is there such a thing as a "legal ROM?"

4. Is it legal to backup computer software that was originally vended in some form of permanent storage format, such as a
    game cartridge or CD-ROM?

5. What is "fair use?"  How does the concept of "fair use" apply to emulation?

6. How can the Internet legally support the emulation community?

section last revised 20 January 1999

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