Ensoniq AudioPCI

The Ensoniq AudioPCI is a PCI-based sound card released in 1997. It was Ensoniq's last sound card product before they were acquired by Creative Technology. The card represented a shift in Ensoniq's market positioning. Whereas the Soundscape line had been made up primarily of low-volume high-end products full of features, the AudioPCI was designed to be very simple, low-cost product to appeal to system OEMs and thus hopefully sell in mass quantities.

Low cost

Towards the end of the 1990s, Ensoniq was struggling financially. Their cards were very popular with PC OEMs, but their costs were too high and their musical instrument division was fading in revenue. Pressure from intense competition, especially with the dominant Creative Labs, was forcing audio card makers to try to keep their prices low.

The AudioPCI, released in July 1997, was designed primarily to be cheap. In comparison to the wide variety of chips on and sheer size of the older Soundscape boards, the highly integrated two chip design of the AudioPCI is an obvious shift in design philosophy. The board consists only of a very small software-driven audio chip (one of the following: S5016, ES1370, ES 1371) and a companion digital-to-analog converter (DAC). In another cost-cutting move, the previously typical ROM chip used for wavetable patch set storage was replaced with the facility to use system RAM as storage for this audio data. This was made possible by the move to the PCI bus, with its far greater bandwidth and more efficient bus mastering interface when compared to the older ISA bus standard.

Features

AudioPCI, while designed to be cheap, is still quite functional. It offers many of the audio capabilities of the Soundscape ELITE card and surpasses the other Soundscape cards. Notably, AudioPCI supports several MIDI digital effects (reverb, chorus, and spatial enhancement) when used with Microsoft Windows 95 and later versions of Windows.

AudioPCI had some surprises for the market. It was one of the first cards to have Microsoft DirectSound3D 4-speaker playback support. The 4-speaker mode is only activated by software supporting the DirectSound3D quadraphonic mode. An oddity is that the rear channel was connected to the same output jack as line input. The jack switches modes if 4-speaker output became active.

The DOS and Windows drivers support wavetable MIDI through Ensoniq's ".ecw" patch set format. Several patch set choices are available, varying in size and instrument quality (2, 4, or 8 MB). Unfortunately, the quality of these sets, although relatively large in size for the time, is less than the 2 MB set on the Soundscape ELITE. The 4 MB and 8 MB set quality is better than the 1 MB patch sets of Soundscape VIVO90, Soundscape OPUS, and SoundscapeDB, however.

The ".ecw" file format (Ensoniq Concert Wavetable) was never made open as had been hoped for by enthusiasts. Consequently, there are no custom wave sets available, in contrast to the huge availability of home-made releases in E-mu's SoundFont format. It was particularly unfortunate because the AudioPCI used system RAM for patch set storage which in itself offers tremendous potential for new patch sets over the traditional ROM storage previously used. It is also disappointing considering the incredible popularity and longevity of the Ensoniq ES1370 chipset and its descendants, some of which were still in use six years after the original AudioPCI board, and the fact that DOS drivers for the far newer Sound Blaster Audigy still use ".ecw" wave sets. These newer cards are unable to use SoundFonts in DOS, limiting them to the three official .ecw wavesets from the late '90s.

DOS compatibility

The AudioPCI boasted excellent DOS support for a PCI sound card. The competing Monster Sound from Diamond Multimedia was limited to running DOS games in Windows 9x-based DOS command windows, meaning DOS compatibility was frequently only reliable through an additional ISA sound card. Creative was struggling with the challenge of legacy support as well, and had created a special SBLink port for motherboards, in order to achieve DOS compatibility for their Sound Blaster AWE64-variant PCI sound cards. However, Ensoniq's DOS driver successfully simulated having a real Sound Blaster-compatible ISA sound card in the computer. Compatibility was achieved through the clever use of the PC's NMI and a TSR program that together virtualized the Sound Blaster hardware. This was a tremendous step forward for the time. However, the DOS driver required a memory manager such as EMM386 to be loaded, potentially reducing compatibility with games. This is not a requirement exclusive to AudioPCI, however, as a number of ISA sound cards used it as well, including the Creative AWE ISA series.

The AudioPCI DOS driver included Ensoniq Soundscape 16-bit digital audio and wavetable support, along with support for Sound Blaster Pro, AdLib Gold, General MIDI, and MT-32. However, without actual hardware for FM synthesis, FM music was simulated using the Ensoniq wavetable, resulting in FM soundtracks sounding inauthentic. DOS MIDI utilizes the same .ecw patch set files as Windows MIDI.

Creative acquisition

Part of the deal when Ensoniq was purchased by Creative Labs was to integrate the AudioPCI DOS driver into the upcoming Sound Blaster Live!. Creative added Sound Blaster 16 emulation to the driver and removed the Ensoniq SoundScape support. AudioPCI itself was re-branded as several Creative Labs sound cards, including the Sound Blaster PCI 64, PCI 128, Vibra PCI, and others. The Ensoniq ES1370 audio chip was revised into AC97-compliant variants, the ES1371 and ES1373, and used for several more years on cards and as integrated motherboard audio.

PCI Bus Digital Audio and Music Controller

The AudioPCI ES1370 sound chip was the next-generation in sound technology from the now defunct technology company Ensoniq. One of the more important innovations found within was the move from ISA to the PCI bus. It was one of the first sound card solutions to offer full MS-DOS legacy compatibility. When paired with a capable codec, such as the AK4531 (pre-AC97), the ES1370 supported the then-latest in 3D audio positioning through 4-speaker surround sound. The chip was also a PCI bus master device that was designed to provide high-speed access to system RAM and resources, for wavetable data and effect processing. Depending on the drivers, it may also be called the Sound Blaster 64/128 in the device manager.

ES1370 was one of the first audio chips to support the Microsoft DirectSound3D audio API. When programs took full advantage of the API's capabilities, the ES1370 was capable of both global spatial and localized 3D sound effects, in both 2 and 4-speaker mode. The chip was capable of spatializing all audio automatically, but still required DirectSound3D usage for specific localization of sounds.

The ES1370 is also emulated as a piece of virtual hardware in Qemu and VMware.

*ENSONIQ SoundScape wavetable synthesis
*2 and 4 MB downloadable sound sets (2 MB = GM, 4 MB & 8 MB = GM+GS+10 drum kits)
*32 simultaneous MIDI voices
*Uses system RAM for sound storage (memory locked or dynamic OS control)
*Multi-algorithm reverb and chorus
*Multiple level spatial 3D sound
*Microsoft DirectSound3D compatible (4 speaker 3D sound with AK4531 codec)
*16-bit Record & Playback at up to 48 kHz
*Support for hardware sound rendering
*Support for EAX 1.0, OpenAL
*Low system overhead, PCI bus master
*100% DOS legacy compatible
*Unlimited digital audio streams
*I²S input
*OPL-FM and MPU-401 emulation
*Only a single, shared IRQ required
*No ISA signals required
*No distributed DMA signals required
*Drivers: DOS, Windows 3.1x, Win'95, WinNT, (WinNT (DEC Alpha), Sun Solaris (SPARCengine Ultra AX), Linux, and BeOS available)

ES1371 and ES1373

-compatible versions.

*Wavetable sound sets: 2, 4, and 8 MB sets
**128 General MIDI wavetable instruments, 61 drum programs, 128 MT-32 instruments, Roland GS Sound set in 4 & 8 MB sets
*Synthesizer: Up to 32 simultaneous voice polyphony, 16 MIDI channels
**Digital effects: reverb, chorus, and spatial enhancement
*Digital audio
**16-bit record & playback at up to 48 kHz (mono/stereo). A/D D/A codec
**Lowest Noise: >Signal-to-noise ratio 90 dbr typical. Frequency response: 20Hz - 22kHz
**Full duplex operation (simultaneous record/playback)
*Supported standards. 100% DOS legacy game compatible:
**ENSONIQ Soundscape, Microsoft Direct Audio (DirectX), AdLib, OpenAL, Sound Blaster Pro (2.0), General MIDI, MT-32, FM (software emulation), MPC 1,2,3
*Drivers: DOS,Windows (3.1, 9x, NT 4.x, 2000, XP)

References

* [http://web.archive.org/web/19980118112636/www.audiopci.ensoniq.com/ "AudioPCI Home"] by Ensoniq Corp., Multimedia Division Product Information, 1998, retrieved December 29, 2005
* [http://web.archive.org/web/19980214014059/http://www.ensoniq.com/ "Ensoniq Corp. Web Site"] by Ensoniq Corp., Multimedia Division Product Information and Support Pages, 1998, retrieved December 25, 2005
* [http://web.archive.org/web/19970607104214/www.ensoniq.com/html/mm-pi.htm "Ensoniq FAQ"] by Ensoniq Corp., Multimedia Division Product Information and Support Pages, 1997, retrieved December 27, 2005
* [http://web.archive.org/web/19980214015733/www.ensoniq.com/multimedia/semi_html/index.htm Ensoniq ES1370 Datasheet] Ensoniq Corp., 1997, accessed January 1 2006.

External links

*AudioPCI DOS drivers, on MAMEWorld [http://easymamecab.mameworld.net/html/snddosdr.htm]

*AudioPCI drivers for older operating systems are available not from the Creative Technology website [http://us.creative.com/support/downloads/] , but from the E-mu Systems web site [http://www.emu.com/support/] . Slightly newer versions are available on gateway.com, [http://support.gateway.com/support/drivers/search.asp?param=ensoniq&st=kw] . AudioPCI drivers are built into Windows 2000 and Windows XP. (May 9, 2007)

* [http://personales.ya.com/sailor/ensoniq/ Ensoniq AudioPCI S5016 User Manual] (Retrieved 2007/08/30)

* [http://www.pcavtech.com/soundcards/eapci/index.htm Technical Tests of Ensoniq AudioPCI ES1370 Sound Card] (Retrieved 2007/08/30)