Editing Macintosh Centris 660AV

{{Infobox computer
| name         = Macintosh Centris 660AV
| image        = [[File:Macintosh_Centris_660AV.jpg|250px]]
| caption      = Macintosh Centris 660AV
| manufacturer = Apple Computer, Inc.
| type         = Personal Computer
| release date = July 29, 1993
| discontinued = September 12, 1994
| price        = US$2,300
| cpu          = Motorola 68040 @ 25 MHz
| memory       = 8 MB RAM (expandable to 68 MB)
| storage      = 230 MB or 500 MB SCSI hard drive
| display      = Supports 512×384 to 1152×870
| sound        = 16-bit stereo input/output
| dimensions   = 3.4" × 16.3" × 15.6" (8.6 × 41.4 × 39.6 cm)
| weight       = 14.0 lbs (6.4 kg)
| os           = System 7.1 – Mac OS 8.1
| predecessor  = [[Macintosh Centris 610]]
| successor    = [[Power Macintosh 6100]]
| codename     = Tempest
| model        = M9040
}}

The '''Macintosh Centris 660AV''' is a personal computer designed, manufactured, and sold by Apple Computer from July 1993 to September 1994.<ref>{{cite web |url=https://everymac.com/systems/apple/mac_centris/specs/mac_centris_660av.html |title=Macintosh Centris 660AV Specs |publisher=EveryMac.com |access-date=2026-02-10}}</ref> It was introduced alongside the [[Macintosh Quadra 840AV]]; the "AV" designation signifies video input and output capabilities and enhanced audio processing. The machine was rebranded as the '''Macintosh Quadra 660AV''' in October 1993 without any internal hardware changes.<ref>{{cite web |url=https://en.wikipedia.org/wiki/Macintosh_Quadra_660AV |title=Macintosh Quadra 660AV |publisher=Wikipedia |access-date=2026-02-10}}</ref>

== Model Variants ==

The Centris 660AV and Quadra 660AV are identical machines with different nameplates. Apple discontinued the Centris line in October 1993, rebranding remaining inventory as Quadra. Configurations included:

* '''M1839LL/A''' – 230 MB hard drive
* '''M9043LL/A''' – 230 MB hard drive with 2× CD-ROM
* '''M9044LL/A''' – 500 MB hard drive
* '''M1840LL/A''' – 500 MB hard drive with 2× CD-ROM

== Architecture and Processor ==

The 660AV uses a full Motorola 68040 processor running at 25 MHz with an integrated FPU, unlike the [[Macintosh Centris 610]] which uses the FPU-less 68LC040.<ref>{{cite web |url=https://support.apple.com/kb/SP234 |title=Macintosh Quadra 660AV: Technical Specifications |publisher=Apple |access-date=2026-02-10}}</ref> The clock input runs at 50 MHz, but the processor itself is not clock-doubled.

=== AT&T DSP 3210 ===

The 660AV includes an AT&T 3210 digital signal processor clocked at 55 MHz. This DSP handles multimedia functions including:

* Real-time speech recognition (PlainTalk)
* Audio processing and effects
* Video compression/decompression
* Telephony functions via GeoPort

The DSP reduces CPU load during video capture and playback operations.

=== ROM ===

The 660AV introduced a new 2 MB universal ROM (codenamed "SuperMario") that would later be used in all PowerPC systems.<ref>{{cite web |url=https://support.apple.com/kb/TA29776 |title=Centris 660AV & Quadra 840AV: 2MB ROM Information |publisher=Apple |access-date=2026-02-10}}</ref> This ROM includes:

* SCSI Manager 4.3
* Sound Manager 3.0
* Vectorized code for easier patching

== Memory and Storage ==

=== RAM Configuration ===

{| class="wikitable" style="width:70%"
|-
! Specification !! Details
|-
| Onboard RAM || 4 MB soldered
|-
| SIMM Slots || 2 (72-pin)
|-
| Standard RAM || 8 MB
|-
| Maximum RAM || 68 MB
|-
| SIMM Speed || 70 ns or faster
|-
| SIMM Types || 4 MB, 8 MB, 16 MB, or 32 MB (64 MB SIMMs not supported)
|}

=== Storage Systems ===

The 660AV uses an internal SCSI hard drive (230 MB or 500 MB depending on configuration). The SCSI direct-memory access chip combined with SCSI Manager 4.3 provides improved disk performance compared to earlier Quadra models.

== Display and Graphics ==

The 660AV has 1 MB of dedicated 80 ns DRAM for video, which cannot be upgraded.

{| class="wikitable" style="width:70%"
|-
! Resolution !! Color Depth
|-
| 512×384, 640×400 || 24-bit (millions)
|-
| 640×480, 800×600, 832×624 || 16-bit (thousands)
|-
| 1024×768, 1152×870 || 8-bit (256 colors)
|}

A second display can be supported with the addition of a compatible PDS or NuBus video card.

== Audio Capabilities ==

The 660AV features 16-bit stereo audio input and output. The AT&T DSP enables:

* PlainTalk speech recognition
* Text-to-speech synthesis
* Real-time audio effects processing
* CD-quality recording and playback

== GeoPort ==

The 660AV is the first Macintosh to include GeoPort, a high-speed serial port technology.<ref>{{cite web |url=https://lowendmac.com/1993/centris-660av-quadra-660av/ |title=Centris 660av (Quadra 660av) |publisher=Low End Mac |access-date=2026-02-10}}</ref> With an optional GeoPort Telecom Adapter, the 660AV can function as a fax machine and modem using software and the DSP rather than dedicated modem hardware.

== Video Input/Output ==

The 660AV includes built-in video digitizing capabilities:

* S-Video input and output
* Composite video input and output (RCA)
* Audio/video connector on rear panel

'''Note:''' The 660AV does not support video mirroring. When outputting to TV or VCR, the computer monitor will be blank.

== Input/Output and Expansion ==

=== Port Configuration ===

{| class="wikitable" style="width:70%"
|-
! Port Type !! Quantity !! Notes
|-
| ADB || 2 || Keyboard and mouse
|-
| GeoPort Serial || 2 || Printer and modem (DIN-8)
|-
| SCSI || 1 || DB-25
|-
| Ethernet || 1 || AAUI-15
|-
| S-Video In/Out || 1 each ||
|-
| Composite Video In/Out || 1 each || RCA
|-
| Audio In/Out || Stereo || 3.5mm
|}

=== Expansion Slots ===

* 1 PDS slot (Processor Direct Slot)
* Optional 7" NuBus slot via PDS-to-NuBus adapter (M9049LL/A), includes DAV connector support

== Design and Features ==

The 660AV uses the same "pizza box" desktop case as the [[Macintosh Centris 610]]. Early Centris 660AV units have an auto-inject floppy drive similar to the 610, while later Centris models and all Quadra 660AV units have a manual-inject drive with a round indentation at the center of the slot.

== Power Supply ==

* Input: 100V–240V AC, 50–60 Hz
* Maximum power: 86 watts

== General Maintenance ==

For detailed maintenance practices including cleaning, PRAM battery management, connector corrosion prevention, and voltage adjustments, refer to the dedicated [[Macintosh Centris 660AV General Maintenance]] page.

== Capacitor Replacement Guide ==

Detailed capacitor replacement guidelines for the logic board can be found on the [[Macintosh Centris 660AV Capacitor Replacement Guide]] page.

== Troubleshooting ==

A comprehensive troubleshooting guide addressing no power, no video, intermittent operation, and other common problems is available on the [[Macintosh Centris 660AV Troubleshooting]] page.

== Technical Details ==

<templatestyles src="Template:StyledTable/styles.css" />

=== System Architecture at a Glance ===

{| class="wikitable styled-table" style="width:90%; text-align:center;"
! Sub-system !! Specification
|-
| '''CPU''' || Motorola 68040 @ 25 MHz
|-
| '''DSP''' || AT&T 3210 @ 55 MHz
|-
| '''Bus width''' || 32-bit data • 32-bit address
|-
| '''ROM''' || 2 MB (SuperMario)
|-
| '''RAM''' || 8 MB standard (expandable to 68 MB)
|-
| '''VRAM''' || 1 MB dedicated
|-
| '''Video''' || Up to 1152×870 @ 8-bit
|-
| '''Sound''' || 16-bit stereo, 44.1 kHz
|-
| '''Disks''' || 1.44 MB floppy, SCSI hard drive
|-
| '''Optical''' || 2× CD-ROM (optional)
|-
| '''Ports''' || ADB ×2, GeoPort Serial ×2, SCSI, AAUI Ethernet, Video I/O
|}

=== Processor Specifications ===

{| class="wikitable styled-table"
|-
! Component !! Specification
|-
| CPU || Motorola 68040 @ 25 MHz
|-
| FPU || Integrated
|-
| DSP || AT&T 3210 @ 55 MHz
|-
| Data Bus || 32-bit
|-
| Address Bus || 32-bit
|-
| L1 Cache || 8 KB (4 KB instruction + 4 KB data)
|-
| System Bus || 25 MHz
|}

== Upgrades ==

Apple offered a Power Macintosh Upgrade Card for US$1,399 that upgraded the 660AV to match the [[Power Macintosh 6100|Power Macintosh 6100/60AV]] specifications. Third-party accelerators include:

* MicroMac Speedy variable speed oscillator (up to 29 MHz)
* Sonnet QuadDoubler (50 MHz 68040)
* MicroMac slot-free 128 KB L2 cache

== Known Issues ==

* The Startup Disk control panel in System 7.5–7.5.3 is incompatible with Quadra AVs. System 7.5.5 fixes this issue.
* Quadra AVs do not support 24-bit addressing mode.
* A "fat" (universal) system must be installed to use a PowerPC upgrade card.
* A dead or low-voltage PRAM battery can cause loss of built-in video.

'''Tip:''' Hold Cmd-Opt-T-V during startup to force the Mac to use a TV as a monitor.

== Service Documentation ==

The official Apple Service Source documentation for this model:

<pdf width="800" height="500">File:Quadra.centris_660av.pdf</pdf>

== See Also ==

* [[Macintosh Quadra 840AV]]
* [[Macintosh Centris 610]]
* [[Power Macintosh 6100]]

== References ==

<references />

[[Category:Apple Vintage Computers]]