In July 1993 Apple introduced two very special Macintosh models, the Centris 660AV and the Quadra 840AV. Although seemingly belonging to different product lines and featuring radically different cases and expandability options, they shared most of their technology, and even more importantly, their raison d’etre.
The two Macs sported an unseen integration of audio, video and voice, setting a new market standard. The “AV” monicker after the model numbers meant that professional audio and video input and output capabilities were already included by Apple and there was no need for third-party expansions.
Both the Centris 660AV (code-named Tempest) and the 840AV (code-named Cyclone) were the first Macintoshes to support 16-bit 48 KHz stereo audio, and could record and play back sound at CD-quality. They also had S-Video and Composite video ins and outs so one could use them to digitize video from a camcorder or other source and route their video signals to a TV set or video recorder. They were also the first Macs that supported Apple’s speech recognition (PlainTalk) out of the box.
All of these amazing capabilities were possible thanks to new and more powerful hardware which had custom circuitry to handle the AV features.
Tempest and Cyclone both featured the sheer power of the Motorola 68040 processor, which was clocked at 25 MHz in the Centris and at 40 MHz in the Quadra, hence surpassing the speed of the mighty, top of the line, Quadra 950. To lighten the load on the 68040 and speed up audio/video-processing Apple included an AT&T 3210 DSP (Digital Signal Processor) chip, running at 55 MHz in the 660AV and at 66.7 MHz in the 840AV.
The two AV Macs were sold with an Apple GeoPort Telecom Adapter Kit which made available to the user many DSP-based telecommunication functions, such as modem, fax, and telephony. Unfortunately, as had happened with the Mac IIfx Application Specific Integrated Circuits, very few applications made use of AT&T’s chip, due to the added complexity of programming it.
Here’s a video showing the developers having fun after completing their work on the motherboard of the AV Macs. It was filmed around 1993 and released with the System 7.1 CD that came with the Centris 660av and 840av.
The Centris 660AV, later renamed Quadra 660AV after the elimination of the Centris line, and the Quadra 840AV were among the last of the professional Macintoshes based on the Motorola 680X0 CPUs but not the last AV models. Their legacy lived on with the PowerMacs, which in many cases implemented their audio/video capabilities thanks to an “AV on a card” concept originally developed, for Tempest & Cyclone.
Note: the Centris 660AV/Quadra 840AV print ad is “courtesy of Apple”.
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