It is amazing, even after nearly 15 years of engagement in my retro PC build project, how many new facts remain to be learned. That is why I am at least as fascinated by retro technology as I am about the game aspect: if I only wished to play the games there are plenty of emulators, virtualizers, and other translation layers more than capable of accomplishing that purpose (modern techniques are even able to improve the experience). That is where I started (from back when I was still a broke college student) but I always had an aspiration to not only cover that which I could not afford back in its heyday but, through getting it all to work despite many unique quirks, have the rewarding experience of accomplishing the technical quest as well.
Unless one has the resources for multiple builds from the same general era, retro computing will always be a compromise. Actually, come to think of it, computing in general is always a compromise; the major difference between systems of the 20th and 21st centuries is that the latter has the benefit of standards consolidation that occurred at the turn of the millennium. The more backwards compatibility diminished the more the emulation scene took advantage of new computing power to more accurately portray old architectures, perhaps best manifested by the fact that DOSBox has become industry standard for retro PC gaming storefronts.
For the vast majority DOSBox is sufficient: with minimal tinkering it can run pretty much any DOS or 16-bit Windows game, with its pick-up-and-play factor as simple as it gets for anyone who understands the basics of how DOS, Windows 3.x, and mainstream gaming standards of the era worked. Yet, evidenced by the multiple forks of DOSBox, the stock program is insufficient for anything beyond this basic gaming criteria as it sacrifices some accuracy and introduces a few quirks of its own. For those of us who require more (and are willing to put in the work to learn around the added complexity) there are full-fledged PC emulators such as PCem and its advanced fork 86box (I use this one), but these likewise still have plenty of room for improvement and particular desired features may have a while yet to be implemented.
At the end of the day authenticity is authenticity, thus why there will not only continue to remain a retro hardware scene but it will continue to develop modern alternatives to replace old components that are dying off. There will eventually come a day in which emulation will be the sole remaining option, and hopefully it will have achieved pristine accuracy well before then. Until then, there are plenty of options that abound (some still highly cost-effective) because, while the original trend-setters typically command a collector's premium, the cheaper alternatives were not necessarily worse...in fact, they could be better.
Today's post will focus on the many different standards of PC sound from the late 80s to the early 2000s, non-comprehensively and focused on the gaming aspect. Some of these, as of this writing, still have no emulation coverage or are only just receiving it. Someday (if my information becomes more complete) I may write an equivalent overview regarding graphics, but that is an even bigger can of worms which will need consideration not about what to include but about what to leave out. In regard to the capabilities and compatibility of these standards I would like to extend advance thanks to my best research sources:
Several YouTube channels including those of the above site proprietors, others such as DOS Storm plus, of course, "thing" feature episodes by the famous Lazy Game Reviews
IBM PCjr/Tandy 1000/IBM PS/1
These standards are unique in that they are inherently tied to their specific hardware, though Tandy 1000 became prominent enough in the 80s to prompt modern production of compatible devices as there are no small number of games (for PC; superior ports may exist on other platforms) in which it was the best sound option. While not technically built on the same architecture, all three of these devices are made similar enough to consider their effects equivalent (it likewise matches the Atari ST sound chipset). For any interested in accommodating any of the above there are plenty of better enthusiast research sources that can explain how better than I ever could since the Tandy 1000 era is a bit before my area of gaming interest, at least as far as the PC is concerned (and pursuing the IBM PS/1 for its specific sound card is no worthwhile endeavor due to its obsolescence in 1990 and limited support, but the morbidly curious may still check the best online source here).
IBM Music Feature Card
Image borrowed from program download page at WinWorldPC.com...everything else on that site is free so I doubt they mind. Music Construction Set is an anomaly: though not exclusive to PC the support of its collective editions for contemporary PC hardware is rather comprehensive, including the original 5150 cassette port (of all things; it was barely used by IBM themselves and only existed as an afterthought to conform to the expectation in 1980 that computers must feature cassette capability). It had a version for PCjr sound and the 1987 edition, last for PC, is the only Electronic Arts title to support the MFC.
While not technically the first audio add-on for PC (let alone other computers), it should also come as no great surprise since 1987 happens to not only be the year of the PC sound hardware but when IBM was attempting to comprehensively remake the PC market in its image (see the PS/2 line and MCA). On the technical front all these ideas had merit, but their execution never had a chance because it was for the wrong reasons: the original IBM PC was open architecture and IBM closing it back up was trying to put the genie back in the bottle, which meant it no longer mattered that IBM hardware was still among the highest quality available. While the IBM name carried enough weight to eventually prompt a good deal of vendor support, it was the blunder that marked the beginning of the end of IBM's involvement in the PC market it created.
The Music Feature Card is a microcosm of this history. It pioneered the practice of putting a synthesizer on an ISA card (Yamaha FB-01 in this case, one of the best FM synthesizers of the time), offering music composition on computer with a powerful capability for those who could exploit it. FM synthesis, while not at the same level as wavetable, was ideally suited for games as proven over and over in Japan.
Yet this supreme exploitation of FM synthesis would historically prove to remain near-exclusive to Japan, the home of companies such as Yamaha who developed the architecture. Just one major Western game company, Sierra On-Line, supported the Music Feature Card (as well as its FB-01 companion plugged in compatible MIDI hardware) in its titles...yet that support comes off as an afterthought since the quality of these particular compositions does not stand up to the same for Roland or even AdLib. It may have had a great instrument set, but end results depend on more than that.
Ultimately, the IBM Music Feature Card is another one of the company's notable failures of the era. The card itself is unobtanium (the FB-01 unit may be easier to find) and no known clones exist, but as of the 2020s the emulation scene has just covered this "lost" standard. Like the PS/1 Audio Card it is more-or-less a morbid curiosity for Sierra fans, but its unexploited musical composition capabilities are the sort of thing that breeds cult enthusiasm.
AdLib
That was more than I expected to write about the MFC, but that seems due since it is not as known due to never becoming a mainstream standard. AdLib, on the other hand, needs no introduction even if the name itself may escape (after all, the company itself died in 1992). Even DOSBox does not support the AdLib standard directly, but that is due to it being assimilated then superseded by the Sound Blaster standard which is something that will be covered further in that section.
The 8-bit, 9-voice monaural FM synthesis thanks to Yamaha's YM3812 (aka OPL2) chipset is, quite simply, the seminal baseline for PC audio. It had limited PCM capabilities that a few games used, but its FM tones would set trends long after its prime in the MIDI era. Competing architectures offered superior capabilities from Day One, but well-composed music and effects continued to sound great out of old OPL2 into the mid-90s.
The fatal flaw proved to be the fact that Yamaha chips were available to anyone, and Singapore-based Creative Labs knew opportunity when they saw how enthusiastically AdLib was embraced as PC gaming sound standard. AdLib continued as baseline standard to the end of the DOS era, but it was not AdLib themselves who reaped the benefits or even got much opportunity to build on what they started. Their legacy can never be forgotten even if it was just this small step.
Creative Music System/Game Blaster
At first that enthusiastic Singapore-based competitor struggled to find footing. Rather than taking the synthesis route the rest of the industry was veering towards, Creative's first computer audio foray built upon cheaper square wave PSG. Admittedly their result was the best such available on PC which earned it a fair amount of game support (by far Sierra though Lucasfilm Games, Accolade, Origin & a few others embraced it for some of their releases).
Less than 100 games in total used CMS for its unique stereo capabilities that still sounded little better than contemporary game consoles. Still, that put Creative on the map and its use of open architecture (built upon a pair of Phillips SAA1099s which were also made available for backwards compatibility in the earliest Sound Blasters) meant it was easily covered when emulation time came. However, since there are few to no games which are best used with square wave audio when synthesized options are available (tastes are always subjective), whether this is worth exploring is very much up to the individual.
Roland Linear Arithmetic (MT-32/CM-32/LAPC)
By far the highest end and least accessible of the 1987 PC audio quadrumvirate, it soared in quality because of its professional architecture...at such a high cost of entry it may have gone nowhere if not for Sierra On-Line's enthusiastic support that included promoting and selling units. By 1990 it had been embraced by MicroProse, Lucasfilm & Origin. While the rise of General MIDI in the 90s somewhat supplanted it, momentum ensured its continued function in the best commercial titles (it was eschewed by shareware developers) in the same stretch of time as AdLib.
Roland support is one of those things that immediately springs to mind when considering what options existed back then but were inaccessible due to high cost or lack of availability. It may not have seemed that way for a time: AdLib was the baseline standard but Roland was the high-end alternative, meaning that success would be denied to future competitors absent some way to accommodate those standards in their hardware. Thus many sound cards from all kinds of vendors in the 90s would, either directly via some emulation or translation of system calls or indirectly via adaption of their support for General MIDI, could enable the Roland option in games...and oftentimes the result was a better listen than AdLib.
But that could only go so far. Not only were both AdLib and Roland so successful in setting standards that [soon enough] they were used in certain manners not originally intended by their inventors, but they did so in an era pre-dating the expectation that end users would have more than one device or standard (Sound Blaster was the first to change this). Thus 1) these devices, designed specifically for music, were also frequently used for PCM (at a basic level) analog sound effects which 2) was only possible exploiting the architecture via its unique system calls thus 3) the results were geared towards these specific devices which of course means 4) results may not match on future devices with <100% backwards compatibility.
Not even Roland's own modules achieved that necessary backwards compatibility; their Sound Canvas series featured MT-32 fallback but that only involved adjusting the instrument set and not translating any unique system calls (and since Sound Canvas pioneered the General MIDI standard, that shortcoming affects everything else which conforms to it). Nevertheless translating the musical instruments is simple enough to be successful more often than not, yet when it comes to older games using features specific to Roland LA devices (for either sound effects or instrument extensions) this approach cannot be wholly recommended.
Hence why Roland LA emulation has been an ongoing enthusiast project for decades, of which Munt is the most developed and successful (hear it for yourself: it is darn near perfect). Not many emulators, even those geared towards vintage PC gaming, include Munt in stock downloads, and because Roland still holds copyright over their LA device ROMs (not that they appear intent on ever doing anything with it) applying those will be a necessary setup anyway. This applies even to hardware-based emulation for retro PCs such as mt32-pi.
Innovation SSI-2001
Relatively little is known about how well this standard was embraced; MicroProse was heavily involved at some point, but rumor has it the actual card never came to market at all. For certain it would not have prevailed against AdLib without being made much more cost-effective, though game support was very limited in the end anyway. With they key exception of Spectrum Holobyte's Falcon A.T. (which supports only this card and nothing else beyond PC speaker), alternatives exist for games in which it does work.
Technically this does no more than bring SID, famously of Commodore 64, to PC. It definitely improves over PC speaker, but whether it does the same over PCjr/Tandy is a matter of debate. Fortunately, for those enthusiastic enough to experiment, it has been both cloned and emulated in the 21st century.
Sound Blaster [2.0]
It is difficult to fathom how a brand continuing to this day once had such humble origins. In fact, it may not have found such spectacular success but for its "revolutionary" approach of setting a new standard while retaining compatibility with a pre-existing one. The Sound Blaster, alongside VGA graphics, placed PC as superior to Commodore Amiga and swept most others aside.
No one embraced Sound Blaster for its backwards compatibility with Game Blaster. By integrating the exact same OPL2 from Yamaha while offering a new 8-bit digital PCM architecture, Sound Blaster could be used with anything made for AdLib and more...an unfortunate turn of events for AdLib Inc. but one they had no standing to do anything about. There were 3 versions: 1.0 came stock with Game Blaster compatibility, 1.5 only made that an option, and 2.0 doubled the fidelity while adding full duplex; all are distinguished from successors by using OPL2 and being strictly monaural (outside of the Game Blaster option since that was stereo).
Even more than AdLib and Roland, Sound Blaster established itself as a standard everyone else had to accommodate in some way or else risk failure; when Sound Blaster compatibility is advertised (including in Creative's Sound Blaster 16 and all successors) it generally refers to this first generation only, which is sufficient for the vast majority of 90s DOS games (and irrelevant for DirectX-era Windows). One caveat for a handful of games (mostly 1993 Apogee titles) is their use of ADPCM effects supported by Creative architecture that may not be covered by a clone or emulator such as the [otherwise greatly-compatible] Yamaha YMF series. Compatibility with original Sound Blaster also means restriction to 8-bit monaural which is actually not that much of a problem because relatively few DOS games went beyond that (and those that did often have native support for whatever alternative is installed).
AdLib Gold
AdLib made an honest attempt at building on the foundation they set in 1987, but the success of Sound Blaster was destined to deny them theirs. It was still their tactical business decision to await availability of Yamaha's new stereo OPL3; whether Creative colluded with Yamaha or just beat AdLib to the punch is another one of THOSE chapters of computing history. At least this time AdLib would not let themselves be supplanted even if they were defeated.
Adlib Gold is, like IBM's Music Feature Card, one of those legends which carries a reputation beyond its actual exploited capability. On its own it is hardly notable because it was already not alone on the OPL3 front, but with its proprietary "surround module" daughtercard it certainly vied to become the pinnacle of FM synthesis on PC. Yet only one game, Dune by Westwood Studios, actually used that whole setup, though several other games would offer native AdLib Gold support (beyond the card's built-in support for Sound Blaster).
After AdLib folded some of their staff were picked up by MediaTrix Peripherals which was located close by, which explains why their AudioTrix Pro not only offered AdLib Gold compatibility but stepped up to the next logical level by using Yamaha's OPL4. While not a stock option in DOSBox its forks and other emulators have AdLib Gold capability, some even emulating the surround module. Yet the bottom line remains the same: as all supported games also offer some kind of MIDI option this is strictly for the fans of FM synthesis (or Dune).
Pro Audio Spectrum
While Creative was focused on one-upping AdLib, new competitors were hoping to one-up Creative in turn. Despite the success of Sound Blaster there were no guarantees of it becoming industry standard, particularly if someone else could be the first to offer substantive improvement. Come 1991, one such competitor proved determined to strike the first blow if not a killing one.
The original Pro Audio Spectrum introduced stereo FM synthesis to the PC, beating both AdLib Gold & Sound Blaster Pro to market. It blazed its own trail, eschewing Sound Blaster support [with the separate Thunder Board available to cover that base] in favor of its own architecture which was, even at this early stage, a substantial risk (alleviated by its use of the same OPL2 thus being 100% AdLib compatible). Yet the risk paid off; in fact, more than a handful of Sierra games only supported stereo FM via PAS and not Sound Blaster Pro.
Lack of Sound Blaster support proved to be a limited liability since developers embraced PAS support at the tune of hundreds of games. Trends, however, suggest the vision (no pun intended) was not so much to beat Creative at their own game as to get a jump on the Multimedia PC standard which was initially defined by Creative technology on the audio front. While the Pro Audio Spectrum 16 and its derivates likewise beat Sound Blaster 16 to market, their ancillary features suggest a focus on more than gaming.
This new trend started in 1993 as a new line of Media Vision cards, the Jazz series, eschewed Pro Audio Spectrum support in favor of Sound Blaster Pro and standard General MIDI connections. Media Vision and Creative were primary drivers of the multimedia kit market that brought the CD-ROM revolution to the masses. Then in the mid-1990s, problems of their own making brought a premature end to Media Vision's market presence and necessitated their resurrection in a different form (see below).
While loved by enthusiasts due to its matching of Sound Blaster's feature sets, wide games support and cleaner audio, there has been no incentive for emulation to embrace the Pro Audio Spectrum standard. Aside from the few Sierra games with exclusive support for stereo FM (alleviated by fan patches, but all such games are probably better played with Roland anyway) it offers no gaming advantage over Sound Blaster Pro. Nevertheless, as of 2024 86box at least (possibly others) now supports it, for whatever that is worth.
Sound Blaster Pro [2]
Achieving stereo FM (as well as stereo PCM) was no one's exclusive domain. It was still the logical next step so Creative built atop standard: 8-bit at 22050 Hz was now in stereo for end users. Yet, as with all other incremental changes, that did not ensure developers would embrace the same for their games.
Making Sound Blaster Pro its own category is for an important distinction: Sound Blaster (mono) support is not necessarily Sound Blaster Pro (stereo) support, so it must be checked whether a card supports one or both; Sound Blaster Pro is 100% backwards compatible with Sound Blaster (except for Game Blaster, which was no longer important anyways). Absent Pro support, stereo PCM effects written specifically for Pro will be reduced to monaural. Finally, there was a brief transition period in which stereo FM was via dual OPL2 rather than OPL3 introduced in the Pro 2; since OLP3 is backwards compatible with OPL2 but not dual OPL2, compositions specifically for dual OPL2 will likewise be rendered monoaural on OPL3.
Roland GS (Sound Canvas)
General MIDI was implemented in 1991, marking the point at which the entire sound industry (not just gaming) standardized wavetable synthesis; pick virtually any DOS game past 1992 and find GMIDI as a music option. As the trendsetter of this new standard, however, Roland retained a position of prominence in its application through the end of the DOS era and beyond. Other card makers could technically follow the standard, but those who did so in their own way risked a repeat of what was already occurring with compatibility for games making unique Roland LA device calls.
That this standard is specific to the GS extensions of the Sound Canvas series is done on purpose, since those were the devices that drove this new standard and all prominent game musicians used some type of Roland SC unit, unique attributes and all, for their compositions. As with all prior synthesis standards, competing devices may have no problem so long as only the standard instruments and system calls, but there are no small number of games geared specifically toward Roland's GS extensions (especially a few composed on early units produced before finalization of the GMIDI standard) which could exhibit quirks on non-Roland units. There is much more that can be discussed about this, but the important point for gaming is, even if it may make MIDI tracks sound better (such as Yamaha's XG units; it is no coincidence that they happen to have a GS compatibility mode), Roland GS is what they were composed for and no notable exceptions exist for Western DOS gamers.
Gravis Ultrasound
Of all devices covered in this history, likely none earned so much enthusiasm from the beginning as this unique product from a company who had started [and would finish] as a maker of PC game controllers (the most famous of which, the Gravis PC GamePad, established a standard of its own). The killer point was not just that the original Gravis Ultrasound was first to provide full CD quality 16-bit PCM, but that it did so in an architecture strongly resembling that of the Amiga Paula chip. This would naturally lead to its strong embrace by the demoscene.
In addition, Ultrasound's featured onboard wavetable synthesis that could be mapped with the first form of what are now known as soundfonts, making it essentially the first General MIDI card (technically it was only GMIDI capable: compliance depended on how instrument patches matched the standard). While all its forms would only ever offer 1 megabyte of soundfont space (paltry by standards of the mid-90s) the default banks made remarkable game music for the time, even possessing a good degree of MT-32 compatibility. For digital sound Gravis, like Media Vision, took the risk of blazing its own trail; however, rather than put all their eggs in one basket, they included Sound Blaster compatibility via what was the first software-based emulator of the standard [of many that would follow].
As with all such trailblazers full fidelity 16-bit audio in games was only possible by directly supporting the GUS standard, but that proved to be little problem since virtually all notable DOS games of the 1990s supported GUS either natively, by patch, or via one of its emulators. The only trouble spots would be: 1) AdLib due to terrible FM emulation; 2) Roland LA extended effects since compatibility failed to account for those; 3) Sound Blaster Pro stereo since that emulator only covers Sound Blaster. Another limitation of note involves only the original GF1 chipset (the later AMD InterWave lifted this limitation): its fidelity decreases with the number of digital channels utilized (not a practical issue for DOS games).
When Windows 95 and DirectX set new means of exploiting high-fidelity audio in sound cards, that was the effective end of unique value for GUS and other architectures that took their own approaches: at that point 16-bits at 44100 Hz was baseline standard and Windows came stock-capable of using any card with compatible drivers. Due to its revolutionary approach, demoscene embrace and extensive games support, GUS was an early candidate for emulation; use in DOSBox is merely a matter of pointing to its driver package and setting up a supported game. While its wavetable synthesis is weak and its digital capabilities quickly matched then exceeded, there are a good number of games (chiefly shareware and Amiga ports, but a few originals too) that were made to exclusively support its full digital capabilities.
Pro Audio Spectrum 16
For a time in the early 90s Media Vision enjoyed being the trendsetter by beating Creative to market on each new level of implementation; PAS16 releasing ahead of Sound Blaster 16 was no exception. It was a relatively small number of games supporting PAS16 16-bit audio (none exclusively), but this is as good a point as any to note the trends of standards support that was developing. GUS, as elaborated prior, achieved Sound Blaster compatibility entirely via software emulation...which is eventually where the rest of the market (including Creative themselves) would go as soon as it became cost-effective. PAS16 was one of the key exceptions as its compatibility was achieved in hardware via integrating the architecture of the Thunder Board, an older Media Vision card which may have been the first purpose-made Sound Blaster clone. By 1992, Sound Blaster had definitely become a standard no one could ignore.
Sound Blaster 16
It was important to cover that point because now Creative will follow that same trend. Technically the Sound Blaster 16 was basically an even match to PAS16, but the technicalities were beside the point. What mattered now was market embrace, and Creative became the Microsoft of PC sound.
Having now reached 16-bit full-fidelity plus implementing connections for General MIDI devices (albeit not well for a while, what with egregious bugs cropping up such as the infamous "hanging notes") it is at this point the second revolution was achieved and a new baseline ready to be standardized. Yet that is not what occurred among enthusiast gamers for many reasons but one glaring: while fully backwards compatible with Sound Blaster it was not with Sound Blaster Pro, which would not have been much of an issue except that stereo PCM implementations at that point utilized Sound Blaster Pro so far as Creative devices went (PAS16 users could rightfully claim no issue here since their backwards compatibility was for a standard that was stereo all along). That being said, in retro terms this may actually be a non-issue since stereo games generally supported more than just the Creative implementation (even Wolfenstein 3-D happened to use calls for its stereo routines that ARE compatible with Sound Blaster 16, contrary to what was popular online opinion for a while despite being verifiable by anyone switching between both in DOSBox).
Hence, Sound Blaster 16 tends to be a favorite for those seeking compatibility [even at the expense of quality]. All of Creative's succeeding ISA cards are backwards compatible in hardware, then when their PCI cards came along those which retained DOS support implemented compatibility via software (all, in turn, backwards compatible with Sound Blaster). Yet, it is really not that spectacular in big-picture terms because: for DOS, it is just one of several 16-bit standards with those effects only being used if games or programs support them; for Windows, the hardware capabilities have no distinctive features to DirectX.
Windows Sound System
A quick elaboration needs to be made specific to (but not exclusive to) 16-bit Multimedia Windows. At the end of 1992 Windows 3.1 and its enhanced capabilities had been fully established and exploration was made for their gaming potential. The brainstorm that would eventually yield WinG, the technical predecessor to DirectX, also included a new type of sound card and standard to go with it.
Very few DOS games supported this standard natively but compatible cards enjoyed capabilities beyond those of all the 16-bit devices on market at the time when used in Windows. The realized game benefits are still only so much, but this makes it important enough to note because the PCM fidelity was second-to-none. Later in the decade new cards matched this fidelity while building on features, rendering moot the distinction of this standard (particularly since, with DirectX, drivers matter more than hardware).
ESFM (ESS Audiodrive)
Like Creative, this is a company still in operation today; unlike Creative, they long ago ditched the PC sound market despite having once been one of its biggest players. Its AudioDrive family is a long-running line of gradually-improved chipsets on ISA which was punctuated by the PCI Solo-1, prized among gamers (contemporary and retro alike) for their superb DOS compatibility and (as of this writing) supreme affordability. It did not hurt at all that: 1) their build quality is remarkably less noisy and perceived as qualitatively superior to most Creative offerings; 2) their chipsets were widespread among 90s-vintage implementations of built-in motherboard audio along with sound cards by numerous third parties.
Similar to Media Vision they started with a simple Sound Blaster clone, going cost-effective route by eschewing FM synthesis altogether. Then they built on that tremendously, offering not only one of the earlier cards with Sound Blaster Pro support but bypassing Yamaha to implement their own FM synthesis standard which became known as ESFM (Creative did the same with CQM, which is generally regarded as inferior to other hardware-based alternatives). By the time AudioDrive reached its peak it offered an early implementation of binaural 3D sound (though no information has been found on any games using the ESS 3D standard).
The point specifically being covered here involves ESFM. While not 100% authentic to the real deal (of course) OPL3, it is not only considered close enough by most but even better by many. A fair number of games offer AudioDrive support but for most that refers to its native 16-bit PCM (it is worth noting that, unlike the Yamaha YMF or Ensoniq Soundscape lines, ESS supports Creative ADPCM calls) including by no less than the original Tomb Raider. Not that many games have been found to take advantage of the synthesis extensions offered by ESFM (in a parallel to AdLib Gold), but any gamer can still enjoy ESFM music in any OPL3 game and judge for themselves if it is as good or better.
Ensoniq Soundscape
This standard bears tremendous resemblance to Gravis Ultrasound...which is no coincidence. Like Gravis, Ensoniq took the risk of entering the PC sound card market in order to raise standards in their own way; unlike Gravis, Ensoniq had already been a music company for years and knew that would be a strength in their endeavor. Other good points: the Gravis Ultrasound chipset happens to be a variant of an Ensoniq design, and Ensoniq itself was no stranger to the computer audio industry having been responsible for sound implementation on the Apple IIGS.
The history of Ensoniq Soundscape is a microcosm in computer transitions of the mid-90s. The S-2000 followed the standard of including CD-ROM since they were not yet standard on motherboards, and on the other end was the AudioPCI which cut costs by implementing systems more in software. While the Soundscape Elite is considered the pinnacle of the line, all Ensoniq cards are known for their wavetable synthesis which, naturally (coming from an electronic music company), was among the best of on-board offerings of the era.
Yet even worse than GUS are the compatibility quirks. GUS had the advantage of being on market for years when Soundscape launched thus many more games supported its native 16-bit PCM. When native support is offered in games Soundscape is a strong as they come (particularly its MIDI, albeit not Roland GS compatible), but its software-based FM synthesis is awful (though its MT-32 fallback can be OK) and Sound Blaster emulation fails to cover ADPCM.
AudioPCI is a different beast: because it was popular among OEM system builders it is still easy to find cheaply (unlike most of the ISA Soundscapes) and it retains Soundscape compatibility for DOS games, but what makes it more interesting is its pioneering soundfont implementation. Others, beginning with Gravis, supported software-based wavetable settings, but Ensoniq AudioPCI was the first to completely lift the limitations of onboard ROM or RAM by using the host computer's RAM instead. When Creative acquired Ensoniq they got that technology as well, leaving the ISA Soundscapes on their own as unique and at that really only for their strong MIDI.
Sound Blaster AWE
In a technical sense Sound Blaster AWE32 is, strictly for PCM and FM synthesis, no different than Sound Blaster 16. One of the quirks of Sound Blaster 16 is that its MPU-401 implementation (for connection to external MIDI modules) had shortcomings, and part of how Creative compensated for that was the Wave Blaster connector which could accommodate MIDI daughtercards. Anyone in the know is able confirm AWE32 as Sound Blaster 16 with integrated Wave Blaster.
Functionally the AWE family is distinguished little from clones and competitors, effectively making their biggest advantage Creative branding (thus "guaranteed" to meet standard). It does have an additional feature though it was not exclusive (Ensoniq Soundscape had the same): onboard [& upgradeable] RAM that could expand the soundfont footprint to enable potentially higher quality. It was actually Creative who invented what is understood as the soundfont today, though initially they were called soundbanks.
There are a few games (mainly PlayStation ports) that use this soundbank capability to upload their own custom patches exclusively with AWE32. All other titles supporting AWE32 natively do so strictly in the context of being able to access the onboard wavetable without needing to go through AWE's [memory-hungry] MIDI driver. As a base-level synthesizer AWE32's stock MIDI is not too bad, but AWE64 is better while a synth by a real music company (i.e. Roland, Yamaha, Ensoniq) is best.
The Windows 95 Transition
DOS gave way to 32-bit Windows around the time computer gaming audio reached its essential peak; how could better than CD audio be called for anyway? Soundfonts had already gone mainstream which potentially broke the ceiling on MIDI quality, yet MIDI itself was on the way out since many games opted to stream CD audio off their discs (plus it was just a matter of time before hard drives grew large enough to tolerate digital audio files of the same quality). Game development applications consolidated around Microsoft DirectX which, while often remembered for its 3D-accelerated graphics development, had an audio side as well.
It was mentioned above that ESS brought support for 3D positional audio in binaural form on its cards, but it took the introduction of DirectSound 3D and the efforts of others to make something more of it in games. Remember that back in the 90s through early 2000s home surround sound setups were far less common, even more infrequently with the home PC connected. The typical setup being either a pair of desk speakers or stereo headphones, that was the target arrangement for these protocols for enhancing basic stereo into a pseudo surround sound.
Aureal A3D
The first such approach did not even use Direct-Sound 3D because it was developed concurrent to it. The first generation, known as A3D 1.0, was basic enough that its calls were simple enough to translate that it became like a new Sound Blaster: easy enough to clone in hardware or emulate in software that eventually everyone else was able to accommodate it without any input from Aureal itself (the irony is that Aureal Semiconductor just so happened to be the resurrection of what had formerly been Media Vision). Regardless A3D 1.0 was first out the gate and garnered a great deal of game support from developers who grasped that 3D sound (even pseudo 3D) was a new level of immersion worth exploring alongside the on-going revolution in 3D-accelerated graphics. If a compatible game runs on modern Windows and A3D's software-based implementation drivers are able to install effectively (driver stability was the one point of frustration with A3D hardware), this can still be experienced by gamers today.
When competition arrived that utilized and extended DirectSound 3D (which, again, A3D did not use), Aureal opted to build upon their own proprietary standard rather than run with the crowd. Gamers with the right hardware who experience it can testify that A3D 2.0, while only supported by so many titles, is a quality of its own...provided it can be made to work with its finicky drivers. This, as well as A3D 3.0 which required a driver update and was supported by a small handful of games, only works in 2nd generation Aureal chipsets which means (along with the fact that it has yet to be successfully emulated) significant demand remains for the original hardware.
Environmental Audio Extensions
It was Creative who desired to remain at head of the standards train, producing the first extension of DirectSound 3D commonly used in games that would also turn out to be the longest-lasting with 5 levels' (over 3 generations) worth. Because the first two levels of EAX extended DirectSound 3D it could, like A3D 1.0, be emulated by competing hardware to varying degrees of success. The second generation (like A3D 2.0) made that no longer the case: for EAX Advanced HD it was Creative hardware or going without, but that was less a matter of proprietary protocols and more the fact that Creative was the only vendor bothering to continue producing sound cards for gaming in the 21st century due to the establishment of standard motherboard audio.
Having already assimilated Ensoniq Creative turned their monopolistic tendencies against rival Aureal, beating them down with frivolous legal actions culminating in their bankruptcy and acquisition. Owning A3D now as well as EAX Creative chose to completely deprecate the former in favor of the latter, but it is arguable how much they got to enjoy their success as the 2000s saw a rise in use of surround sound for home computers and developers leaning towards accommodating multi-speaker setups thus overriding any need for binaural 3D. Windows Vista, which discontinued support for DirectSound 3D, finally nailed that coffin and brought this remarkable era to a close.
Sensaura
Today's final section shall end on a familiar tune: Creative assimilating yet another audio company. Sensaura as a protocol (not so much a standard) tied to both A3D and EAX, and while it was not accommodated on many devices for PC it did at least succeed in a variant being selected to drive the DirectX-based audio for Microsoft Xbox. On PC its compatible cards with proper drivers were able to independently implement A3D 1.0, EAX 1 or 2 (first generation), and a unique DirectSound 3D extension of its own that not only further built over EAX but could translate some A3D 2.0 calls. This has Sensaura fondly remembered by a few who know it as a viable all-rounder for 3D sound in the gaming era centered around Windows 98.
Creative acquired Sensaura in the mid-2000s when it no longer made a real market difference, but their developments (as well as those of Aureal) doubtless influenced the direction of EAX and Creative's other builds in the 24-bit audio era. ALchemy, their software-based backwards compatibility layer, fails to be all-encompassing at least in regard to EAX-supported games, but with many of them including surround speaker options anyway that is not as big an issue as it seems. The 6th console generation was the first to really blur the line between PC and console gaming; today both still have their proponents despite the everyday practical difference being waxed minute.
Closing
There are plenty of other sound device companies (some with their own unique features) that could have been covered here, but I wanted to stick to the most relevant standards for retro PC gaming. It was my choice to not elaborate further on MIDI implementations because that is a world of its own with many contenders, the vast majority of which had no PC gaming involvement whatsoever. I considered making a glossary of terms and abbreviations, but I figure that should not be necessary because the interested audiences this is written for should either already be enthusiasts familiar with such details or spurred to research further for oneself (which is one reason why I listed the most helpful sources at the beginning).
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