Emulation:  Right or Wrong?
aka "The EmuFAQ"


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

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Module One:  The Emulator
Part 1 - The Basis for Emulation

And so it begins ....
Ambassador Kosh, Babylon 5
OverClocked #72, "OverRocked BC #2" © 2000 David Lloyd


     I've been actively involved with the emulation community in one form or another since the early days of 1998.  I first became aware of the concept back in September of 1988 when I bought my beloved Amiga 2000 personal computer.  You see, there was this nifty accessory you could get from Commodore called the PC Bridgeboard - a combination of hardware and software that would allow you to run IBM PC software on a suitably equipped Amiga.  "Cool!" I thought, but I couldn't afford the price tag for either the A2088 XT or A2286 AT model at the time.
      I was bemoaning this fact to fellow Amiga user Ken Gillum one day, and he merely shook his head.  "You know," he said, "Commodore used to sell a piece of software for the old A1000 that would let you run IBM software on an Amiga without the hardware."
     "No way!?" I said, hardly believing my ears.
     "Way," he replied, "and I've got it.  Come to my house this weekend and I'll give you a copy."
     That was my first step into the wonderful world of emulation.  The program that my friend gave me was called Transformer, and it did indeed let you run IBM software on an Amiga without special hardware.   True, it was buggy as all out, only supported text-based software, and had no support at all for hard drives, but who wanted to play "Beemer" games on an Amiga anyway?  The business apps, such as WordPerfect 4.2 and Lotus 1-2-3, were what mattered, and those were handled ably by that creaky old software emulator.
     It was several months later, sometime in mid-1989, now having established myself as one of the Amiga gurus in my local area, that I paid a visit to a nearby Commodore dealer to get a copy of the demo for the brand-new and highly acclaimed Psygnosis game Shadow of the Beast.  The late Dick Conrad, owner of the Commodore Connection and a close friend of ours, was quite excited.  "You've got to check this out!" he said, steering me and my ol' Amiga hacking buddy Steve Smith, aka "Skerran," to his display A2000.  "Have you heard of A-Max?"
     "No," I said, feigning ignorance.  Of course I had, but I didn't know of anyone who had gone to the trouble of buying it.
     "Then watch this," he said as he turned on his A2000, activated A-Max, and then inserted a MacOS System 6 disk for bootup.  Skerran almost fell over when he saw this, but I held my tongue and watched.  A short time later, we were looking at a flickering blue-and-white MacOS screen displayed on the store's interlaced A1084S monitor.
     "Now it's a Macintosh," the store owner stated proudly.
     For those of you who might not remember, A-Max was a combination hardware and software product along the same lines as the PC Bridgeboard, except that it gave the Amiga the capability for near-perfect Macintosh emulation.  All you needed was the A-Max emulation software, the A-Max adapter, a MacOS boot disk, and a set of Mac BIOS ROMs.  Apple was at that time dead set against any type of cloning of their proprietary hardware, so the only way A-Max could remain legal was to force its buyers to go to a licensed Apple vendor and order a set of real Mac BIOS ROMs.  These plugged into the adapter, and the A-Max software worked in conjunction with them to reconfigure an Amiga into a pretty decent Mac clone.  Yes, it was a bit of a specialty product, it was pricey, and it really wasn't worth the trouble if you were stuck with an interlaced monitor - but oh, was it ever so neat!
     Two months later I was in another state at a meeting of several software pirate groups to shop the latest warez offerings from the Amiga underground.  I was on good terms with one of the better groups in the region, and one of its members (who shall remain anonymous) tossed me a white 3.5" disk.  "Have you heard of A-Max?" he said.
     "Yeah," I replied, "but it's no good without the Apple BIOS."
     "Here's a cracked copy," he said, "and you don't even need that f--kin' adapter to run it."
     He was right.  After testing the disk with the latest release of Steve Tibbet's VirusX (we had to be careful even back then), I booted the thing up.  Sure enough, there was A-Max, but running without the Mac BIOS!  "How did they do it?" I asked.
     "Easy," the hacker replied, "they just dumped the BIOS and hard-wired it into the emulator.  Now it can run all by itself."
     I thanked him for providing the copy, and a week later was back at the Commodore Connection.  I pointed to Dick's dusty display A500 off to one side - he rarely used it anymore since his A2000s had arrived.  "I can make A-Max run on that," I said.
     "Not without the adapter, and I'm not taking it off the A2000," he replied.
     "I don't need it," I answered.  "Watch and see."  And with that, out came the little white disk.
     About five minutes later, a glassy-eyed and slack-jawed Dick Conrad was staring at a MacOS screen on his A500.  "How in the world did you do that?" he asked.
     "This version doesn't need the adapter," I answered.
     "Where did you get it?" he asked.
     "Same place your techs get their stuff," I shot back, winking as I did so.
     "I see," he replied with a grin.  "What do I need to copy it?"
     "Nothing special," I answered.  "Project D will work just fine."
     "Here's a disk and my copy of Project D," he said, shoving them into my hands.  "Go for it."

     Emulation has come a long way since those initial heady days on the Amiga (and the Atari ST and Mac - let's not forget their contributions, either), but the basic premises and questions remain the same.  The recent attempt by Nintendo to formulate an official company policy on emulation may have sparked a lot of ridicule, but was actually a good thing to happen at this time.  As emulation is now suffering from something of a bad reputation in the public eye, perhaps it is time to take a look back at where we've been, where we're going, and the legal ramifications that are involved.  The two stories above, which actually happened to me in my younger, wilder days, serve to illustrate all of the main questions concerning the so-called "legitimacy of emulation" and the various questions that it poses.
     I shall attempt in the ensuing series of discussions to try and lay to rest some of the myths and half-truths that shroud the emulation community within a grey legal haze.  Rather than just tossing out highly emotional statements as most users prefer to do (and of which I am guilty at times), I will be citing specific examples from the history of the emulation community as well as related issues within the computer industry as a whole.  I will also cite specific provisions of various laws, statutes, and regulations where applicable; and I will also refer to a wide range of court cases (i.e. "case law") that have a direct impact on the emulation issue.


     The first question one might ask is the most obvious one:  "Are emulators legal?"  It depends on how you ask the question - are you dealing with the concept of emulation as a whole, or are you referring to the creation of an emulator?  In order to resolve this dilemma, let's take a look at the purpose of an emulator.  We will save the legal question concerning the creation of an emulator for later.
     What is an emulator? An emulator is a product designed to imitate one system with another so that both accept the same data, execute the same programs, and achieve the same results (American Heritage Dictionary, Second College Edition, s.v. "emulate").  Emulators can be pure hardware, pure software, or a combination of both.  In the two stories that I relate from my past, the Amiga Transformer program would be considered a pure software or "true" emulator, while both the PC Bridgeboard and the unadulterated A-Max would be considered "combo" emulators because of the combined hardware and software approach in their design.  An example of a pure hardware or "firmware" emulator would be the Sega Genesis/MegaDrive's VDP mode 4, which converts the console into a functional Sega Master System emulator running entirely on its internal hardware, and all of which is activated via a special code received from the console's cartridge port.
     For those of you who are still new to the emulation scene and don't have any idea what I'm talking about, let me describe emulation another way.  Many of you are using IBM PC compatible computers running Microsoft Windows as its primary operating system.  Take a moment to look inside the Accessories folder.  You'll see about a dozen or so programs and directory entries, but the one I want you to look at is named Calculator.  Run it, and see what happens.  You should now have what looks like a little calculator on your screen - not all that different from the little credit card sized ones they sell on the J-hooks at your local grocery store.  If you've got one handy, go get it and set it beside your keyboard.  Now, I want you to work a few math problems on Calculator; if you've got the real thing handy, then double-check your results with it.  Neat, eh?  That's because Calculator "emulates" a real calculator - it allows you to conveniently work math problems without having to have a real calculator handy, and it serves just as well as the real thing anytime you're sitting at your computer.  Since Calculator is a computer program that does not require any kind of extra hardware (other than the computer itself), it would be considered a pure software-based, i.e. "true" emulator.
     This brings us to the underlying idea behind an emulator.  It is something designed to perform a task or series of tasks that you couldn't otherwise do because they weren't intended for your hardware.  That's the core concept.  You're not supposed to be able to play Sega Master System games on a Sega Genesis, but you can with the use of the PowerBase Converter - a unique cartridge port accessory that includes a special boot ROM which reconfigures the console so it can support the older game cartridges.  You're not supposed to be able to run Windows software on a Macintosh, but SoftWindows makes it possible.  Speaking of my beloved old Amiga 2000, you're not supposed to be able to run Amiga software on a high-end IBM PC compatible, but Cloanto's Amiga Forever (the commercially licensed version of UAE) makes that possible.  The concept is sound and has been employed by both vendors and users in various ways over the years.  Emulation is a valid use for computer hardware regardless of who you are.


     So why even emulate at all?  Four reasons.  First, convenience.  Remember the example of Calculator?  Beats digging in the ol' office desk for the one that your secretary borrowed last week and never returned.  Second, back-compatablity.  Assuming you have a need to keep using an older piece of software, it sure is nice to have some kind of setup that let you use the old stuff with newer hardware - that way you can junk the old hardware and free up some space.  Third, software development.  It's nice being able to develop for a custom system using one that you already know how to use.  Fourth, the old standby of cross-platform support.  It's a lot cheaper to buy just one multipurpose computer system and different kinds of software to use with it than buy different systems for different purposes and the software to match.  Emulation allows you to save your money by running software on the system you have that may have been intended for use with a system that you either do not have or cannot afford.
     Need some examples of emulation in action?  Well, we've already got Calculator from Microsoft Windows as an example of convenience.  There are plenty of examples for back-compatability, but I'll limit myself to three:  the PowerBase Converter for the Sega Genesis/MegaDrive; the "real 8086" mode of all Intel and Intel-derived 80286 processors and their descendants; and the famous "triple mode" operating system feature of the venerable Commodore 128.  As for software development, the best example I know is Sega's TeraDrive, which was a specially modified 386SX PC-AT compatible computer with on-board Sega videogame hardware, produced and distributed almost exclusively to game developers and the like.  That also serves as a good example of cross-platform support, since it allowed the use of both IBM PC and Sega Genesis/MegaDrive software within the same box.
     With the various back-compatability and SDK issues whizzing about in the minds of computer programmers, it was inevitable that some bright young programmer would say to himself, "Screw the US$1000 or so for the SDK - I'm going to write my own."  On the other side of the fence, you have a passionate home console owner with a computer background and no spares to be found in local stores to replace his worn-out game carts due to the obsolescence of the console.  "Forget that," he says, "I'll just write an emulator and dump the cart ROMs instead."  Bounce over to the frustrated personal computer user who has just learned that the game he bought will not work on his new system because it was designed to run on an older, now-obsolete model that is no longer in production.  "No way," he says, "If the store won't give me my money back, then I'll find some way to run it anyway."  Along those lines, dare we forget the retrotechs - who just flat out love old computer stuff and will do almost anything to keep it alive?  "We're tired of hunting for out-of-production parts," they say.  "This neato program will let me run this software on my newer systems."  Or what about the big corporate vendor, who needs to find a way to make its old software work with its soon-to-be-released new system in order not to lose a good-sized chunk of its customer base?  "What old hardware?" they say. "We'll just make an emulator for our new system."  Many faces, but the same set of dice.  Thus was the modern emulation community born.


     The concept of emulation was invented by systems engineer Larry Moss of IBM back in 1964 as part of the development effort behind the IBM System/360 family of mainframe computers.  They were quite revolutionary for their day, being the first mainframes to use integrated circuits all the way throughout their design, which meant that programs hard-coded for older, transistorized IBM computers would not work with the new product line.  Three approaches were tried by IBM - first, a series of computer simulations running entirely in software (sound familiar?), then next came the Moss proposal, and finally a straightforward firmware approach that resulted in the IBM 1410S (that sounds familiar, too).  Neither of the two extremes would work with the System/360 product line, though - the "software simulations" were just too slow and the firmware approach used in the IBM 1410S was way too machine specific.  There had to be a comfortable middle ground in there somewhere, and that is where Larry Moss stepped into the picture.
     Moss used the word emulator to set his proposed project apart from the pure software and firmware approaches by others.  His design "strove to be like" the real McCoy without actually being it (per the dictionary definition of the word), running the same programs at a comparable speed but on a completely different system.  The actual emulator was a mix of hardware and software components, which worked in conjunction with each other to allow higher-end System/360 computers to behave as if they were an IBM 7070 mainframe, one of the top computers of its day.  Moss believed then, as the passing years have shown, that the closer the hardware in the target system was to the system being emulated, then the better the emulator would function.  This is why he chose the "combo" approach, as it offered the best compromise between portability and cost.  It had only those hardware components that were really required for effective emulation at a decent speed, with the remaining issues being handled by the emulation software.  Stuart Tucker, who was in charge of System/360 development issues, liked the idea and gave Moss the go-ahead.  The rest, as they say, was history.  The System/360 went on to become IBM's best-selling product line of that era, and the 7070 Emulator by Larry Moss was so successful that many customers were running their old software under emulation well into the early 1970s without a hitch.  Thus it was that the technology known as emulation was born, as well as the three basic approaches to designing an emulator, and we owe it all to Larry Moss and his coworkers at IBM.  For his achievement, Larry Moss is today considered to be the father of computer system emulation.


     Credit for the birth of personal computer emulation is given to three of the true pioneers in the personal computer industry - Tim Patterson, Don Burdis, and Bill Gates.  In 1980, Microsoft released the Z80 SoftCard, its first hardware offering and its first such accessory for the Apple II personal computer.  This US$350 add-on was comprised of a plug-in card and accompanying software that would allow Apple II users to run CP/M software on their machines.  Tim Patterson designed the actual hardware side of the emulator, with Don Burdis managing the product (and the requisite software) in its final stages and Bill Gates making sure that everything stayed on track.  Remember, these were the days before the arrival of the IBM PC and MS-DOS.  You couldn't do everything with software alone, because the available technology was quite limited.  CP/M, invented by Gary Kildall, was the dominant operating system for business computers prior to IBM's arrival on the scene, but it was incompatible with the Apple II's MC6502 CPU.  Microsoft's SoftCard had an on-board Zilog Z80 CPU, which was one of the CPUs that CP/M was designed to work with.  The Microsoft Z80 SoftCard was the very first computer system emulator for a personal computer, allowing the Apple II to greatly expand its software base and contributing a great deal towards the success of that classic computer.  CP/M itself would remain a viable operating system well into the mid-1980s, and products similar to the SoftCard subsequently appeared for other personal computer systems of the decade.  The presence of these various CP/M emulators meant that users didn't have to ditch their old CP/M software while learning how to use their new systems, and personal computer users grew to appreciate the concept just as much as mainframe users had before them.
     In 1982, computer chipmaker Intel announced the release of the 80286 CPU.  This was one of the company's first true 16-bit processors intended for mass production and represented a quantum leap forward in personal computer processing capability.  All that was well and good, except that Intel had a problem - almost all of the software of the day was 8-bit in origin.  Fortunately, these were the early heady days for IBM, as its IBM 5150 Personal Computer (aka the IBM PC) had taken the business computer market by storm and thus set the standard for all machines that would follow in its wake.  The IBM PC used the 16-bit 8086 as its CPU, but its system bus and software base were 8-bit in nature.  Compaq, who was in the process of winning the legal battle over the right to use the Phoenix reverse-engineered BIOS in its PC clones, favored the compatible 8-bit 8088, which Intel had designed as a cheap alternative to the 8086.  With this in mind, Intel devised a unique solution to ensure that existing 8086/8088 software would work with their new CPU.  The Intel 80286 was designed to operate in either one of two modes:  standard mode, using a 16-bit data path and 16-bit memory addressing; and real mode, using an 8-bit data path and 8-bit memory addressing.  In doing this, Intel had unintentionally created the first firmware emulator for a personal computer, since the 80286's real mode perfectly emulated that of an actual 8086 CPU.  It should be noted that 8086 "real mode" remains to this day part of every Intel CPU released for the personal computer market.
     Videogame emulation had its beginnings around this time, during the heady days of the Atari Video Computer System (VCS, later redubbed the Atari 2600), as manufacturers rushed to tap the new and rapidly expanding home videogame market.  The Atari VCS was the undisputed top dog until 1982, when rival manufacturer Coleco released its ColecoVision console.  It was a superior product, in fact a somewhat retooled Japanese MSX personal computer in disguise, and its more powerful capabilities provided Coleco the means by which they could tap into the existing market for Atari VCS games.  Coleco offered a special adapter for the ColecoVision, the Expansion Module #1, that allowed their console to use videogame cartridges designed to work with the Atari VCS.  Atari promptly sued for patent infringement, but lost in the courts when it was ruled that the product did not violate any Atari patents.  Coleco later "thanked" Atari for their generosity in 1983 by releasing the Gemini, a 100% clone of the Atari VCS.  The ColecoVision Expansion Module #1 is nowadays considered by most to be the first videogame system emulator, but the first "true" videogame emulator would not appear until some eight years later (Yuji Naka's unreleased NES emulator for the Sega MegaDrive). It should be noted that so-called "cart adapters" were made by many different manufacturers for various systems, each supporting different cartridge formats, and continued to be manufactured right up until the days of the N64 in the late 1990s, which was the very last videogame console to use the cartridge format.
     The threshold of so-called "true" emulation with regards to today's systems was crossed in 1985 thanks largely to the arrival of one particular personal computer - one that would forever change the industry in many ways.  We're still dealing with Commodore, but with an entirely different system - the legendary Amiga personal computer, generally regarded as the most powerful personal computer of its day, the world's first multimedia computer, and the first computer system to openly support emulation technology.  The Amiga was so powerful that Commodore really didn't know what to do with it, but at least they had the good sense to realize that it needed to be IBM compatible in order to stay alive in a market dominated by PC clones.  The Amiga design team had already foreseen this need, and had a working prototype of a combo IBM PC emulator on hand to demonstrate to Commodore executives.  The literature of the day describes two parts, with the software side called the Transformer and the hardware side called the TrumpCard.  It was well received, but Commodore insisted on a number of changes (such as ISA card support for the TrumpCard) that delayed the emulator's arrival on the market by a full year.  In the meantime, this gave rival computer maker Atari the chance to hurry development of its own prototype IBM PC emulator, which first demonstrated in a "smoke-and-mirrors" demo at the rollout for the Atari ST in mid-1985.  Their IBM PC emulator development was accelerated and the product was rushed to market as soon as possible, finally making it to store shelves in early 1986. Thus it was that PCDitto by Avant-Garde Software for the Atari ST can lay claim to the title of being the first IBM PC emulator released to the general public.  It was a pure software product (i.e. a "true" emulator) and notoriously slow, but the fact that it was available at all spurred Commodore's own efforts in this regard.  The software for the Amiga prototype emulator was quickly recompiled to remove the need for hardware support and released shortly thereafter by Insignia Solutions as the A1025 Transformer, Commodore's own "true" IBM PC emulator program.  It was not much better than PCDitto, but at least Amiga users would have an IBM PC emulator to tide them over for a few months, and with that the original Transformer/TrumpCard concept was abandoned for good.  The rest of the year was spent with the retooled TrumpCard concept, and it was finished in time for the 1986 winter trade shows under the name of the PC Sidecar.  It was universally reviled at the time for various and sundry reasons, but would eventually serve as the basis for IBM hardware support in the next generation desktop Amiga that Commodore then had under development.  That machine that was eventually released in 1987 as the Amiga 2000, and it would prove to be the workhorse of the Amiga product line - emulation support and all.
     Atari may have been first to market and can still claim credit for theirs being the first "true" IBM PC emulator, but it is Commodore and the Amiga design team that must be given credit for having the first working IBM PC emulator.  In fact, so many emulators for various systems, ranging from the well-known to the obscure, were eventually developed for the Amiga that it earned the unofficial nickname of "the chameleon machine."  No other machine of its day had the capabilities for emulation that the Amiga had, and only recent advances in personal computer technology have brought these abilities to other platforms.  The Amiga's reputation for emulation is one that no other personal computer system has managed to supersede as of this date.


     The concept of emulation was turned on its head in 1988 by a young man named Simon Douglas.  He was the driving force behind the development of A-Max, a Macintosh emulator for the Amiga and the first Mac emulator for that platform.  Readysoft demonstrated their Mac emulator at the World of Commodore show in November of that year, and it immediately drew the attention of everybody at the show.  It received rave reviews and a number of write-ups in the major personal computing magazines of the day.  Like the PC Bridgeboards by Commodore that were introduced for the Amiga 2000 at the same show, A-Max was a combo emulator, incorporating both hardware (an external adapter) and software components (the A-Max program) in order to provide the widest possible range of performance and capability.  Its external hardware adapter (and its later internal carded incarnation) required an actual piece of a Macintosh computer in order for A-Max to work, and that "missing part" was a genuine Macintosh BIOS 128K chipset (two chips, as I recall).  There was a big difference between A-Max and the other Mac emulator that preceded it, however.  A-Max represented the first time that a fully functional emulator had been commercially released for a given vendor's proprietary system.  There had been an earlier product for the Atari ST (Aladdin), but its capabilities were rather limited and it was quickly relegated to well-deserved obscurity. A-Max transformed a suitably equipped Amiga into a true Mac clone in every sense of the word, and Apple wasted no time in quickly voicing their objections to the product.
     There was no question that in-house emulation of a vendor's own products was perfectly acceptable.  There was no debate that neither licensed nor developmental emulation of proprietary platforms was legal, and a number of such products had already appeared.  There had never been a problem with the older CP/M emulators, due to their widespread acceptance and the lenient usage terms by which CP/M had been made available.  There was no problem with emulating the IBM PC ever since IBM had lost the court battle over the Phoenix BIOS.  But a commercially vended emulator for the Mac?!  Everybody knew how jealous Apple was of its little black-and-white computer, going so far as to use every trick in the book (and then some) to ensure that the Mac would not be cloned.  That is what caused all the buzz in the personal computer industry at the time, and many predicted that Readysoft was going to be in for a long and nasty lawsuit at the hands of the proprietary-minded Apple Computer Corporation.  Does this sound familiar, N64 and PSX emulator users?  It was the same thing that you are going through now, except that it happened a decade ago with an unauthorized emulator for a personal computer system.
     What happened next is a matter that remains shrouded in mystery.  Apple continued to strenuously object to A-Max, decreeing that it was infringing use of proprietary Macintosh technology.  Many Amiga users of the day, myself included, remember the widespread fears and discussions about a possible Apple lawsuit against Readysoft.  Strangely enough, though, object was just about all Apple ever did.  Nothing happened, and that was the biggest surprise of all.  Well, almost nothing.  The only public move Apple made over A-Max was to try and dry up all sources of loose Mac BIOS chipsets, but it did little good.  Apple distributors and repair centers with dead or disabled Macs quickly pulled the BIOS out of those systems and were quite happy to sell them to cash-toting A-Max users.  Eventually, Apple gave up on this tactic, and by the following year A-Max had become an established part of the Amiga and Mac communities, who now had something in common - even if it was only an emulator. Not only did A-Max remain a viable product on the Amiga market for several years afterward, it also became one of the most touted emulators in the Amiga arsenal, spawning its own line of copycat products (Shapeshifter, Emplant, Fusion).  Though it was eventually superseded by its competitors, A-Max was one of the products that helped build the Amiga legacy.  Macintosh emulation is quite commonplace nowadays, and it was A-Max that blazed the trail for later efforts in this regard.
     So why didn't Apple sue Readysoft?
     Because they couldn't.  There was no way for them to win, and they knew it.
     Wow!  You mean ... even back then ... and they couldn't?  How did that come about?
     The following explanation is part reason and part conjecture, based on what facts are known and on careful research of the legal issues involved.  Apple has refused the opportunity to comment on the affair even at this late date, so perhaps this may be the only answer that we will ever have.  While it is incomplete and given to surmise, it is a reasonable explanation given the data at hand.
     The legal department at Apple knew full well that unauthorized duplication of copyrighted computer code, especially a computer's operating system, both in BIOS and on software, is illegal; in fact, they had helped establish the precedent some five years earlier over the Franklin ACE 1000, an illegally produced Apple II clone computer (Apple v. Franklin, 1983).  Simon Douglas and his team were also aware of this, as well as the dispute over the reverse-engineering of the IBM PC BIOS (IBM v. Compaq, 1982), so they had deliberately designed A-Max in such a fashion that it would not infringe upon Apple's intellectual property rights.  The Amiga and Mac used similar processing hardware and similar components in a similar fashion, and the only real difference between the two computers was their respective operating systems and communications ports.  This was the reason why the combo approach was chosen for A-Max.  Its hardware adapter contained the minimum amount of hardware required for full Mac computability, and that amounted to no more than the custom Appletalk port and Mac external floppy connector, as well as the appropriate sockets for a genuine Mac BIOS chipset.  The emulation software handled the rest, reconfiguring the Amiga internals for proper Mac operation.  The fact that almost identical hardware was involved explained why A-Max was such a solid product, and also reinforced the original supposition by Larry Moss that similar systems would make for a faster emulator.
     In retrospect, reconfiguring the Amiga floppy disk drives to read native Mac floppy disks was probably one of the most brilliant pieces of work in the original version of A-Max.  It gave Amiga users who did not have access to external Mac floppy drives the ability to use Mac software without having to convert the disk to another format; thus, you could use a real MacOS system disk to boot up the emulator.  Not only was this extremely convenient, but it was also legally prudent, as we will later learn.  A-Max could handle original Mac software in its native format; therefore, software-related issues in any possible dispute were neatly sidestepped.
     The requirement of a genuine Mac BIOS chipset was another gutsy yet well-reasoned move, since Simon Douglas and his team did not have either the resources or desire to reverse-engineer it.  Forcing the use of the actual chipset neatly killed two birds with one stone.  It saved them from the long and arduous reverse engineering process and the inevitable lawsuit that would have resulted, and it provided for some small compensation back to Apple in the form of profits from Mac BIOS sales.  It was not as much as Apple would have gotten from selling an entire Mac, but it was money in their pocket nonetheless; thus, it could be said that Apple was making money every time someone bought a copy of A-Max.  In addition to the initial purchase of A-Max by a potential user, the buyer would also have to cough up extra money to Apple for the proprietary Mac BIOS that was required to make A-Max work.  It was a brilliant idea and one that was subsequently borrowed in later products, although the concept of requiring an outside BIOS would be perverted sooner than anyone would realize (remember the A-Max bootleg?).
     As an aside, it should be noted that Apple's other legal dispute at the time may have played a part in their eventual muted response to the rise of Macintosh emulation.  Remember, the A-Max affair arose about the same time that Apple was considering suing Microsoft over the release of Microsoft Windows, which it felt was an unlawful infringement of MacOS on multiple counts.  Put yourself in Apple's shoes for a moment.  You have before you two different potential lawsuits against a possibly infringing vendor - one which you may not win based on past case law precedent (A-Max), and one which you may very well win for the same reason (Microsoft Windows).  Which are you going to pursue?
     To sum it all up, there would have been no way that Apple could have proven willful intellectual property infringement on the part of either Readysoft or Simon Douglas and his team.  They had been very careful in the way they had designed A-Max, and their foresight proved itself in the long run.  The question of Macintosh emulation remained the center of much debate during the better part of 1989, even after A-Max finally made it to market that summer, and everybody within the Amiga and Mac communities held their collective breath over the affair.  When the year finally ended, A-Max had emerged unscathed, and all of us breathed a collective sigh of relief.  Apple had decided not to challenge the legality of Macintosh emulation, and in doing so unknowingly set a legal precedent for emulation technology that remains with us to this day.  I call it the A-Max precedent, named after the emulator at the center of the dispute, and it is as follows:

The A-Max precedent
It is lawful for a third party to develop an unauthorized emulator for a proprietary system, provided that said emulator cannot be shown to violate the intellectual property rights of the original system vendor in any way.

And with that, the word began to spread - excitedly discussed among the Amiga user community, whispered around the PC clones in many an office, and commented upon in front of the Macs at the local schools.  Emulation of proprietary systems was now permissable.  There was no more debating the matter.  And as we Amiga users of that day saw a steady stream of emulators begin to appear for various systems and wondered to ourselves what system would be emulated next, and as an indignant Apple flailed away at Microsoft in the courts over the release of Microsoft Windows, we knew something special had happened.  Though we could not put a label on it at the time, the resolution of the A-Max affair had kicked off what is now called the Golden Age of Emulation (1989 - 1998).  The technology known as emulation was no longer bound by proprietary desire, and we owe it all to Simon Douglas and the Commodore Amiga.


     So now we're back where we started.  "Are emulators legal?"  The answer is a resounding "YES!"  The concept of emulation is perfectly legal regardless of the nature of the system involved and has been in use for many years now.  So much for that.  The next question that comes to mind is how one goes about creating a legal emulator.  Before we can do that, we first need to try and come to an understanding of the basic concepts behind intellectual property protection and the various forms that it takes.  It is best to know how the legal system may affect your intended emulation project, and it is that forum that we shall discuss next.


1.   What is an emulator?

2.   What are three different kinds of emulator?

3.   What are four reasons for creating an emulator, and what are some examples of each in action?

4.   Why would one might want to develop or obtain an emulator?

5.   What desire of the computer industry gave rise to the concept of emulation?

6.   Who is considered to be the father of emulation technology?  Can you tell in brief the story behind the very first emulator?

7.   How did emulation get started on personal computers?  Who were the people behind it, and what was their product?  What did it emulate, and why?

8.   How did the development of the Intel 80286 CPU contribute to the rise of emulation?

9.   What are the origins of videogame emulation?  Why was that product not a real emulator?

10. What legal battle can be said to have "primed the pump" for videogame emulation?  How was this important?  Why was such a thing possible with a mere videogame console?

11. Why is the Commodore Amiga remembered as "the chameleon machine?"

12. Who was responsible for the first "true" IBM PC emulator?  What was the product?  How did it come about?

13. What product changed the application of emulation technology forever?  Why was it so significant? How did it reinforce one of the guiding principles of emulation?

14. What is one explanation as to why Apple failed to file a lawsuit against this "significant product?"  Be sure to give specifics that back up the main points of your answer.

15. What significant precedent did this "significant product" set?  What does that precedent say?  What does it mean?


1.   Can you describe some of the emulators that arose from the legitimization of proprietary system emulation?  Who made them?  What systems do they emulate?  Are each of these considered legitimate products to the best of your knowledge?  Why

2.   How did IBM's failure to stop the PC clone vendors contribute to the eventual rise of the emulation community?

3.   How did videogame emulation actually get started?

4.   Is emulation legal, at least from a vendor's perspective?

5.   What are your thoughts as to the legality of a noncommercial (i.e. unlicensed or freeware) emulator?

The EmuFAQ (c) 1999 Sam Pettus - section last revised 10 March 2000.