Macintosh Centris 660AV
 | |
| Macintosh Centris 660AV | |
| Specifications | |
|---|---|
| Manufacturer | Apple Computer, Inc. |
| Type | Personal Computer |
| Released | July 29, 1993 |
| Discontinued | September 12, 1994 |
| Intro 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 / Firmware | System 7.1 – Mac OS 8.1 |
| Predecessor | Macintosh Centris 610 |
| Successor | Power Macintosh 6100 |
| Codename | Tempest |
| Model no. | M9040 |
The Macintosh Centris 660AV is a personal computer designed, manufactured, and sold by Apple Computer from July 1993 to September 1994.[1] 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.[2]
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.[3] 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.[4] This ROM includes:
- SCSI Manager 4.3
- Sound Manager 3.0
- Vectorized code for easier patching
Memory and Storage
RAM Configuration
| 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.
| 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.[5] 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
| 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
System Architecture at a Glance
| 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
| 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 6100/60AV 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.
See Also
References
- ↑ Macintosh Centris 660AV Specs, EveryMac.com—link(accessed 2026-02-10)
- ↑ Macintosh Quadra 660AV, Wikipedia—link(accessed 2026-02-10)
- ↑ Macintosh Quadra 660AV: Technical Specifications, Apple—link(accessed 2026-02-10)
- ↑ Centris 660AV & Quadra 840AV: 2MB ROM Information, Apple—link(accessed 2026-02-10)
- ↑ Centris 660av (Quadra 660av), Low End Mac—link(accessed 2026-02-10)