Macintosh Quadra 840av Specs- M9020

Macintosh Quadra 840avReleased as a replacement to the Quadra 950, the Quadra 840AV was a very powerful machine capable of video playback whilst performing other tasks simulatneously. Although very similar in appearance to the Quadra 800, the 840AV was far more powerful. It offered true multitasking, employing multi-tasking aware System software.  Similarly, its Geoport modem offered the ability to answer the telephone, whilst still performing other tasks. The only other similarly equipped Macintosh at the time was the Quadra 660AV. The 840AV was ultimately the fastest Quadra ever produced and proved highly desirable.

Audio Visual Capabilities:

The AV stood for Audio Visual and the Quadra 840av featured a number of ports to it’s rear that added both line in and video in.  However, the built in video recording capabilities of the Mac were quite limited, with both framerates and resolutions being in the region of 320×240 at 24 fps.  The addition of a special AV Macintosh nubus card increased this to 640×480 at 30fps with millions of colours.


The Apple Macintosh Quadra 840AV incorporated a 40 MHz 32 bit Motorola 68040 processor, on a 32 bit 40mHz backside bus.  It’s frontside bus ran at 80mHz, leading to some confusion over the true speed of the processor. The CPU was supported by 8k of level 1 cache but lacked any level 2 cache. Interestingly, this mac had a rather large 2MB ROM, which permanently stored information necessary at power on.


The 840AV shipped with either 8 MB (Order No: M9025LL/A or M9028LL/A) or 16MB (Order No: M1836LL/A, M1837LL/A or M1838LL/A) of RAM. It offered the ability to run 128MB ram in total through the addition of 4 x 32MB 72 pin 60 ns SIMMs.


The Quadra 840AV shipped with either a 230 MB (Order No: M9025LL/A or M9028LL/A), 500 MB (Order No: M1836LL/A or M1837LL/A), or 1.0 GB (M1838LL/A) hard drive. An optical drive (CD Rom – Dual Speed) was offered as an optional extra and a 1.44MB floppy drive was fitted as standard.  A single drive bay remained free, offering the option to install a second optical drive or hard drive.  All drives ran on two seperate SCSI chains, using the industry standard 50 pin connector.

Video & Graphics:

Notably, this system included 4 x VRAM slots that offered support for up to 2MB VRAM.  With the standard 1MB fitted, the 840AV supported resolutions of 512×384 and 640×400 (24-bit), 640×480, 800×600, and 832×624 (16-bit), and 1024×768 and 1152×860 (8-bit).

Quadra 840av portsHowever, when upgraded to 2MB VRAM, the computer supported resolutions of  512×384, 640×400, 640×480, and 800×600 (24-bit/ millions of colors) and 832×624, 1024×768, and 1152×870 (16-bit/ thousands of colors).

A second display could also be added via a NUBUS video card, offering both extended display and Mirrored Display mode. An Audio-Visual card, powered by an AT&T 66.7mHz 3210 DSP processor offered accelerated  S-video and RCA video input/output (SEE above).

Ports & Connectivity:

In addition to a single ADB port, the Quadra 840AV sported a DB-15 video output port, dual Serial Geoports (printer and modem), SCSI (DB-25) port, AAUI-15 ethernet port, S-video input, S-video output, mono sound input and stereo 16 bit sound output.

Introduction Date: July 29, 1993 Discontinued Date: July 18, 1994
Processor Speed: 40 MHz Processor Type: 68040
Processor Upgrade: N/A FPU: Integrated
System Bus Speed: 40 MHz Cache Bus Speed: N/A
ROM/Firmware Type: Macintosh ROM ROM/Firmware Size: 2 MB
L1 Cache: 8k L2 Cache: N/A
RAM Type: 72-pin SIMM Min. RAM Speed: 60 ns
Standard RAM: 8 MB, 16 MB Maximum RAM: 128 MB
Motherboard RAM: None RAM Slots: 4
Video Card: Dedicated VRAM Type: VRAM SIMM
Standard VRAM: 1 MB Maximum VRAM: 2 MB
Display Support: Single Display Resolution Support: 512×384-1152×870
Standard Hard Drive: 230 MB, 500 MB, 1 GB Int. HD Interface: SCSI
Standard Optical: 2X CD-ROM (optional extra) Standard Disk: 1.44 MB
Standard Modem: None Standard Ethernet: AAUI-15
Expansion Slots: 3 NuBus Expansion Bays: 1 (5.25″)
Case Type: Tower Form Factor: Mac Quadra 800
Apple Order No: M9025LL/A Apple Subfamily: Macintosh Quadra 840AV
Apple Model No: M9020 Gestalt ID: 78
Battery Type: 3.6V Lithium Battery Life: N/A
Original Mac OS: 7.1 Supported Mac OS: 7.1-7.5.1, 7.5.3-8.1
Dimensions: 14.0 x 7.7 x 15.75 Avg. Weight: 25.3 lbs (11.5 kg)