Macintosh Quadra 840AV
Encyclopedia
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 Macintosh
es. 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.
Ahead of its time, 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.
The Quadra 840AV came in a similar case to the earlier Macintosh Quadra 800
(the power button was moved to the front and the debugging switches were omitted). However, the 840AV was significantly different on the inside. Apart from the faster processor, it lacked the 800's Processor Direct Slot
and second ADB port, but added a DAV slot (in line with NuBus slot A) and the new GeoPort. Also, unlike the 800's 8 MiB of fixed RAM on the logic board
, all of the 840AV's memory was in SIMM
s (this is the reason why the minimum amount of memory is lower).
, featuring easily accessible audio input, audio output and video input ports of its own, which could be fed by an ADC adapter cable connected with the rear AV ports of the AV Macs.
The later Power Macintosh 6100, 7100, and 8100 returned to the "AV on a card" concept, which was later abandoned with the 7500/8500 series machines, and then re-introduced with the "Wings" AV "personality card" of the Power Macintosh G3 "Gossamer" / "Artemis" machines.
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
that is a part of Apple Computer
Apple Computer
Apple Inc. is an American multinational corporation that designs and markets consumer electronics, computer software, and personal computers. The company's best-known hardware products include the Macintosh line of computers, the iPod, the iPhone and the iPad...
's Quadra
Macintosh Quadra
The Macintosh Quadra series was Apple Computer's product family of professional high-end Apple Macintosh personal computers built using the Motorola 68040 CPU. The first two models in the Quadra line were introduced in 1991, and the name was used until the Power Mac was introduced in 1994...
series of Macintosh computers. It was introduced in July 1993 alongside the Centris 660AV
Macintosh Quadra 660AV
The Macintosh Quadra 660AV is a personal computer that is a part of Apple Computer's Quadra series of Macintosh computers. When it was originally introduced in July 1993 alongside the Quadra 840 AV it was called the Macintosh Centris 660AV, but it was renamed without any major changes in the...
, 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
Power Macintosh 8100
The Power Macintosh 8100 is a personal computer that is a part of Apple Computer's Power Macintosh series of Macintosh computers...
took a very similar position in Apple's product lineup.
At the time of introduction, its 40 MHz Motorola 68040
Motorola 68040
The Motorola 68040 is a microprocessor from Motorola, released in 1990. It is the successor to the 68030 and is followed by the 68060. There was no 68050. In keeping with general Motorola naming, the 68040 is often referred to as simply the '040 ....
CPU and interleaved RAM
Interleaving
In computer science and telecommunication, interleaving is a way to arrange data in a non-contiguous way to increase performance.It is typically used:* In error-correction coding, particularly within data transmission, disk storage, and computer memory....
made it the fastest Macintosh available, topping both the nominally higher-end Quadra 950
Macintosh Quadra 950
The Macintosh Quadra 950 was the third desktop computer in Apple Computer's Quadra line. It was based on Motorola's 68040 microprocessor rather than the 68LC040 . It replaced the Quadra 900, increasing the CPU clock rate from 25 MHz to 33 MHz, and improving the graphics support...
and the Quadra 800 by 7 MHz. It remains both the fastest Quadra and the fastest 68k
68k
The Motorola 680x0/m68000/68000 is a family of 32-bit CISC microprocessors. During the 1980s and early 1990s, they were popular in personal computers and workstations and were the primary competitors of Intel's x86 microprocessors...
Macintosh of all time, since all later high-end Macintoshes were PowerPC
PowerPC
PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
-based Power Macintosh
Power Macintosh
Power Macintosh, later Power Mac, was a line of Apple Macintosh workstation-class personal computers based on various models of PowerPC microprocessors that were developed, marketed, and supported by Apple Inc. from March 1994 until August 2006. The first models were the Power Macintosh 6100,...
es. 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
Digital signal processor
A digital signal processor is a specialized microprocessor with an architecture optimized for the fast operational needs of digital signal processing.-Typical characteristics:...
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.
Ahead of its time, 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
S-Video
Separate Video, more commonly known as S-Video and Y/C, is often referred to by JVC as both an S-VHS connector and as Super Video. It is an analog video transmission scheme, in which video information is encoded on two channels: luma and chroma...
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
GeoPort
GeoPort was a serial data system used on some models of the Apple Macintosh. GeoPort slightly modified the existing Mac serial port pins to allow the computer's internal sound hardware to emulate various devices such as modems and fax machines. GeoPort could be found on late-model m68k-based...
Telecom Adapter Kit introduced with the AV Macs added many DSP-based telecommunication functions, such as modem, fax, and telephony.
The Quadra 840AV came in a similar case to the earlier Macintosh Quadra 800
Macintosh Quadra 800
The Macintosh Quadra 800 is a personal computer that is a part of Apple Computer's Quadra series of Macintosh computers....
(the power button was moved to the front and the debugging switches were omitted). However, the 840AV was significantly different on the inside. Apart from the faster processor, it lacked the 800's Processor Direct Slot
Processor Direct Slot
Processor Direct Slot or PDS introduced by Apple Computer, in several of their Macintosh models, provided a limited measure of hardware expandibility, without going to the expense of providing full-fledged bus expansion slots.Typically, a machine would feature multiple bus expansions slots, if any...
and second ADB port, but added a DAV slot (in line with NuBus slot A) and the new GeoPort. Also, unlike the 800's 8 MiB of fixed RAM on the logic board
Logic board
A logic board is the Apple equivalent of a motherboard. The term logic board was coined back in the 1980s, when the compact Macs at the time had two separate circuit components. The term "logic board" stuck over the years of Macintosh manufacturing, even in the non-all-in-one Macs...
, all of the 840AV's memory was in SIMM
SIMM
A SIMM, or single in-line memory module, is a type of memory module containing random access memory used in computers from the early 1980s to the late 1990s. It differs from a dual in-line memory module , the most predominant form of memory module today, in that the contacts on a SIMM are redundant...
s (this is the reason why the minimum amount of memory is lower).
Trivia
The new AV machines were first to ship standard with an internal CD-ROM drive (earlier Quadra and Centris models were available with the built-in CD-ROM drive as optional extras). The operating system installation package came on CD-ROM rather than a series of floppy disks whenever the CD-ROM drive was included. A hidden QuickTime video included on the original Quadra 840AV/Centris 660AV "Install Me First" CD-ROM, shows the jubilant Cyclone / Tempest design team in the midst of celebrating their accomplishment. In this video, a Cyclone (840AV) prototype logic board is shown. The logic board is fitted with a 25 MHz 68040, a number of rework wires, and most conspicuously, a daughter card nicknamed "Karma", on which the audio and video input/output ports are located. Notably, the audio and video ports on the card are front-facing, positioned as though they would protrude from an opening in the lower front of the case, where they are more easily accessible to the user. According to a member of the team, the "AV on a card" feature was omitted, because there was not enough room for it in the case. Coinciding with the introduction of both AV Macs, Apple introduced the Apple AudioVision 14 DisplayApple AudioVision 14 Display
The Apple AudioVision 14 Display is a 14-inch Trinitron display that was manufactured by Apple Inc. This display is unique because it is the only display ever to use the HDI-45 connector, capable of transferring video to the screen, video capture input from an S-Video source, audio output, audio...
, featuring easily accessible audio input, audio output and video input ports of its own, which could be fed by an ADC adapter cable connected with the rear AV ports of the AV Macs.
The later Power Macintosh 6100, 7100, and 8100 returned to the "AV on a card" concept, which was later abandoned with the 7500/8500 series machines, and then re-introduced with the "Wings" AV "personality card" of the Power Macintosh G3 "Gossamer" / "Artemis" machines.
External links
- New Mac Blazes Technology Trails review from BYTE Magazine
- Quadra 840AV specifications at AppleSpec
- Macintosh AV Series Monitor Support at Apple.com
- Quadra 840AV at apple-history.com
- Quadra 840AV profile at Low End Mac
- Quadra 840AV at EveryMac.com