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Macintosh Quadra 840AV

Macintosh Quadra 840AV
Macintosh Quadra 840AV.jpg
Release date July 29, 1993
Introductory price 3500
Discontinued July 18, 1994
Operating system System 7.1-System 7.1.2, System 7.5-Mac OS 8.1, or with PowerPC upgrade, Mac OS 9.1
CPU Motorola 68040 @ 40 MHz
Memory 8 MiB, expandable to 128 MiB (60 ns 72-pin SIMM)

The Macintosh Quadra 840AV (code names: "Quadra 1000", "Cyclone") is a personal computer that is a part of Apple Computer's Quadra series of Macintosh computers. It was introduced in July 1993 alongside the Centris 660AV, the "AV" after both model numbers signifying video input and output capabilities, as well as enhanced audio. It was discontinued in July 1994, with no immediate replacement – however, the later AV versions of the Power Macintosh 8100 took a very similar position in Apple's product lineup.

At the time of introduction, its 40 MHz Motorola 68040 CPU and interleaved RAM made it the fastest Macintosh available, topping both the nominally higher-end Quadra 950 and the Quadra 800 by 7 MHz. It remains both the fastest Quadra and the fastest 68k Macintosh of all time, since all later high-end Macintoshes were PowerPC-based Power Macintoshes. The 840AV is also the only Mac to use the 40 MHz-clocked 68040. It also sports a faster 66.7 MHz AT&T DSP 3210 Digital Signal Processor chip, compared with the 55 MHz variant in the 660AV. The on-board DSP was primarily intended to speed up audio/video processing, although few Mac programs made use of this due to the complexity of programming it.

The 840AV and its relative, the Centris/Quadra 660AV, marked a number of firsts for the Macintosh family. They were the first Macintoshes to include on-board 16-bit 48 kHz stereo audio playback and recording capability, as well as S-Video and composite video input and output. To improve video playback, two separate frame buffers were used: one for standard graphics, and one specifically for video. This enabled the live video input to be displayed as a scalable "window" within the Macintosh user interface. They were also the first personal computers that supported speech recognition (PlainTalk) out-of-the-box. The Apple GeoPort Telecom Adapter Kit introduced with the AV Macs added many DSP-based telecommunication functions, such as modem, fax, and telephony.


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