1991, exactly as Creative Labs brought their Sound Blaster Pro on the market, a joint development of Advanced Gravis and Forte Technologies came on the market: the Gravis Ultrasound (GUS).
The card was somehow revolutionary. Based on the Gravis GF1 (actually only a clone of the ICS 11614) and equipped with 256 KB RAM (maximum 1 MB) this card could mix 32 voices maximum with 16 bits and at best 44.1 Khz. Therefore it followed the concept of wavetable cards.
The card was directed at amateur musicians, however its abilities interested a quite different group: the demo scene! This scene made (at its time) impressive graphical animations in sync with music. The more something could be offloaded from the CPU, the better. This scene had its own music format ("MOD" - Module), which originated from the Amiga. Its basic idea led to new formats on the PC platform and the Ultrasound was the perfect playback device for them.
This card was prized only little higher than the Sound Blaster Pro, however, offered an essentially better audio quality. Its main advantage lied in its mixing in hardware. This task was usually fullfilled by the CPU, and in times, where a 386 was still highend, this solution came as called. The only thing to do, was to upload the samples to the card. After that, the only thing required was to provide the chip with playback commands (essentially which sample at which volume and which frequency), and it took care of the rest.
While playback quality was on CD level, recording was was only possible at 8 bits, unfortunately. However Gravis offered an add on board, that also removed this deficiency. Titled as 16-bits upgrade module, it was not only this - in fact it was a whole Crystal-DSP with the ability to work with 48 Khz - the same, that was later standard on the Gravis Ultrasound Max (1994, 512K Wavetable).
Ultrasound MAX of 1994
This all sounded too beautiful to be true, if there was not one problem: the card neither possessed an OPL-Chip nor the ability to emulate a Soundblaster by 100 percent, which was a problem in a market mainly controlled by Creative Labs now.
The card was able to work in an AdLib mode, with the GF1 taking over the role of the OPL2 together with a few Samples, and software provided compatibility to the Soundblaster.
Despite them stressing this compatibility, it usually didn't work, or only with a lot of effort. Consequently, Gravis had created a new hardware platform, for which there was practically not any support initially. Therefore they went to game producers, published extensive programming tools together with source codes, and not only few game patches, to crank the support. Bit by bit, this gradually improved the situation, and finally the first games came on the market, that supported the chip directly, also by 1992-1993.
Having this card on the marked finally put Creative Labs into a situation they were forced to improve their Sound Blaster line.
The GF1 itself was a quite simple processor. It always ran at a fixed frequency in a loop, and so it calculated samples continuously. Through the fixed frequency and hence the fixed computing power, it can achieve a sampling rate of 44.1 KHz with up to 16 channels, which will go down to 19.3 KHz when using the all available 32 channels.
Playback was simple: Uplad a mono sample of 8 or 16 bits quality to the sample RAM, say whether to loop it, how fast and loud it should play, and that was all about it.
With this information the chip calculated and mixed the data, with an at this time outstanding feature of interpolation! It works about like this: For example, when playing a sound at a lower frequency than it has, instead of just only stretching and repeating a single sample of that sound, the chip calculated inter values between the two nearest samples. This way it gained the rendering quality that so many people were emphasizing. The topic "Interpolation" is explained more extensively in the glossary.
At almost the same time and price tag of the Sound Blaster Pro, AdLib offered more value for the money. The ADC/DAC worked with 12 bits, instead of only 8 like with the SB Pro, while the card could even be fed with 16 bits sound data.
Additionally, playback runs at 44.1 Khz and stereo - while playing mono, the card could even mix both channels!
An OPL3 was used for the music rendering, and enabled stereo with 20 voices with 4 operators maximum each - at the time of the appearance Creative still offered the first revision the SB Pro, consequently AdLib also was in advance to the competitor there.
A golden sparkling paint finish underlines its name
An outstanding feature was the extremely fine gradation of the mixer, which offered 128 volume steps per channel. An add-on board, which offered the card virtual surround sound together with echo, represented another highlight. I never have heard it, however it is said to improve sound quality significantly. Its main culprit was though that games needed to support it.
There were planned to be different versions: while there was a version dedicated to IBM's Microchannel ("2000 MC"), there also was a plan for a Gold 2000 for the 16 bits ISA slot that added SCSI functionality. Both cards were never produced as AdLib went bankrupt before.
Decidedly, they could cut out Creative with this card easily from the technical side. Crystal clear sound quality thanks to multiple filter steps, bus transfers could be monitored no more involuntarily, a higher sample resolution as well as sampling frequency and nevertheless the same price.
However all this had a catch: also this card was not compatible with the Sound Blaster line! Surely downward compatible with the own AdLib - but nothing more. Annoyingly, however, games wanted to see a Sound Blaster for sample playback. On the AdLib Gold, they therefore didn't play much more than OPL music, supporting games should follow later.
Another problem was the late appeareance on the market. Promises already came early, however this - even if outstanding - result came a bit too late. Consequently, this card is indeed very rare, and very difficult to get.
According to Rich Heimlich, who owned the biggest company for game testing at the time, the card's delay was actually caused by Yamaha, which created a chip for that card that didn't pass AdLib's tests. Creative Labs have already been their bigger customer, they were basically calling their shots, and they played their cards well. Creative made sure that AdLib's chip wouldn't pass testing, because they knew whoever got to market with their new sound card first, would win.
Shortly after the release of this card, AdLib went bankrupt (May 1 1992). They were later purchased by the German company Binnenalster GmbH, which produced the Gold cards again, and in 1994, they were sold to the Taiwan company Softworld. AdLib cards produced by these companies after the Gold had nothing to do with the AdLib Gold any longer.
Mediavision Pro AudioSpectrum Plus / 16 (1991 / 1992)
First Pro AudioSpectrum
The original card (without the plus) could play back and record 8 bits, and had dual OPL2 for the music playback, and finally its 44.1 Khz sample rate, which it also offered when handling stereo data. It was not Sound Blaster compatible in the first place, but the "Plus" and the "16" version were capable of its emulation.
To achieve Sound Blaster compatibility, both variants employed the "Thunder Board" chip, which originated from the first sound card of this company. It was actually additional to the audio codec of the card, and was mixed to the output signal. Hence the card could actually play two digital sound sources at once.
The compatibility made it look better compared to the AdLib Gold, and additionally it offered a SCSI interface for CD-ROMs - an outstanding feature for that time!
Pretty short after the first version, they pushed the 16 bits version of the card, which also offered OPL3 music and was pricely oriented to the SB Pro - about $300.
These qualities and at the same time the good value for the money helped the card to get a quite wide spread, and so also little later its native support by games, where it's often presented in the abbreviation "PAS-16."