Macintosh Quadra 650
 | |
| Macintosh Quadra 650 (photo: Stephen Edmonds, CC BY-SA 2.5, via Wikimedia Commons) | |
| Specifications | |
|---|---|
| Manufacturer | Apple Computer, Inc. |
| Type | Desktop personal computer |
| Released | October 21, 1993 |
| Discontinued | September 12, 1994 |
| Intro price | US$2,780 and US$3,250 |
| CPU | Motorola 68040 at 33 MHz, with FPU |
| Memory | 4 or 8 MB on the logic board, four 72-pin SIMM slots; 132 or 136 MB maximum |
| Storage | 230 or 500 MB SCSI hard disk; 1.4 MB SuperDrive; optional internal CD-ROM |
| Display | Built-in video, 512 KB VRAM expandable to 1 MB |
| Sound | Stereo-capable output, mono input |
| ROM | 1 MB |
| Connectivity | Built-in Ethernet (AAUI-15) |
| Expansion | Three NuBus slots, one processor-direct slot |
| Power | 112 W (Service Source) |
| Dimensions | 152 × 330 × 419 mm (6.0 × 13.0 × 16.5 in) |
| Weight | 11.3 kg (25 lb) |
| OS / Firmware | System 7.1 to Mac OS 8.1 |
| Predecessor | Macintosh Centris 650 |
| Successor | Power Macintosh 7100 |
| Model no. | M2118 |
The Macintosh Quadra 650 is a desktop Macintosh introduced by Apple on October 21, 1993 and discontinued on September 12, 1994.[1] It replaced the Macintosh Centris 650 in the same case (Apple's "IIvx" form factor) with the processor clock raised from 25 MHz to 33 MHz, and Apple services the two machines from one manual.[2][1]
Identification
| Item | Value |
|---|---|
| Model number | M2118[3] |
| Order numbers | M2107LL/A (512 KB VRAM, 230 MB hard disk); M2016LL/A (1 MB VRAM, 230 MB, CD-ROM); M2104LL/A (1 MB VRAM, 500 MB, CD-ROM)[3] |
| Gestalt ID | 36[1] |
| ROM | 1 MB, ID $067C[1] |
| Original system software | System 7.1 with System Enabler 040 v1.1[1] |
Processor
The Quadra 650 uses a Motorola 68040 at 33 MHz with the memory management unit and FPU built in.[2][1] EveryMac notes that the machine is sometimes listed as 66 MHz because the processor's clock input runs at 66 MHz; the processor itself runs at 33 MHz.[3]
Memory and storage
- RAM: 4 or 8 MB on the logic board and four 72-pin SIMM slots taking 4, 8, 16 or 32 MB SIMMs, installed one at a time, 80 ns or faster. The maximum is 132 MB with 4 MB on board and 136 MB with 8 MB on board.[1][4] The Service Source gives 132 MB.[2]
- PRAM: 256 bytes; clock/calendar in a CMOS chip with a lithium battery.[2]
- Floppy: 1.4 MB Apple SuperDrive (auto-inject).[2][1]
- Hard disk: Apple lists 230 or 500 MB; the Service Source allows 80 to 500 MB. An internal 5.25-inch CD-ROM drive was optional.[2][1]
Video
512 KB of VRAM, expandable to 1 MB. VGA (640 × 480 only) and SVGA (800 × 600 only) monitors need an adapter cable.[2] Apple's technical specifications give these maximum depths:[1]
| Resolution | 512 KB VRAM | 1 MB VRAM |
|---|---|---|
| 512 × 384 | 16 | 16 |
| 640 × 480 | 8 | 16 |
| 800 × 600 | 8 | 16 |
| 832 × 624 | 8 | 16 |
| 1024 × 768 | 4 | 8 |
| 1152 × 870 | 4 | 8 |
Ports and expansion
- Two ADB ports (500 mA total); two RS-232/RS-422 serial ports (mini DIN-8, 230.4 kbit/s, 0.92 Mbit/s clocked externally); SCSI on DB-25 (up to six external devices; the computer is always ID 7); DB-15 video; stereo-capable sound output and mono sound input; on-board Ethernet on an AAUI-15 port.[2][1]
- Three NuBus slots and one inline processor-direct slot.[2] Apple's developer note gives 15 W for each of the three NuBus cards.[4]
- The reset/interrupt switch is a separate part removed under Additional Procedures. Apple's note is not to knock it or the light pipe out of alignment when refitting the top cover.[2]
Upgrades
Apple's Service Source covers the internal CD-ROM drive, the Power Macintosh Card in the PDS, and the Power Macintosh upgrade.[2] Apple publishes a separate technical specification for the Quadra 650 with the Power Macintosh Upgrade Card: a PowerPC 601 at 66 MHz with 1 MB of L2 cache and the 68040 retained, Gestalt ID 122, 4 MB ROM.[5] Low End Mac and EveryMac list third-party accelerators as well.[3]
Power supply
Apple's Service Source gives 100-240 V AC, 50-60 Hz, 112 W maximum, not including display power, and the developer note gives the Centris 650's supply as up to 112 W.[2][4] Apple's online technical specifications list "Max Watts: 230", 1.9 A, both for the Quadra 650 and for the Quadra 650 with the Power Macintosh Upgrade Card; the same pages list an AC pass-through outlet, and they do not say what the figure includes.[1][5] The power supply shares its service part with the Centris 650; see Macintosh Centris 650 Capacitor Replacement Guide.
Capacitors
Retro Viator reports that the logic board of its Quadra 650 carried tantalum capacitors and no aluminium electrolytics, while the power supply did contain electrolytics.[6] Check your own board before ordering parts.
PRAM battery
Apple's check is to replace the battery below 3.2 V on the 10 V DC range.[2] Apple gives the type as 3.6 V lithium.[1] Lithium leakage is neutralised with bicarbonate of soda, not vinegar.
Service documentation
- Centris 650/Quadra 650 Service Source[2]
- Macintosh Centris 610 Centris 650 and Quadra 800 Developer Note (covers the Centris 650)
General maintenance, capacitors and troubleshooting
The Quadra 650 shares its case, supply and board family with the Centris 650; use:
- Macintosh Centris 650 General Maintenance
- Macintosh Centris 650 Capacitor Replacement Guide
- Macintosh Centris 650 Troubleshooting
- Retrobrite for yellowed plastics
Related pages
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 Macintosh Quadra 650: Technical Specifications, Apple—link(accessed 2026-09-30)
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 Apple Computer, Centris 650/Quadra 650 Service Source, hosted as File:Quadra.centris_650.pdf (see Centris 650/Quadra 650 Service Source). Specifications pp. 1-11; Troubleshooting pp. 2-14; Take Apart, Top Cover pp. 1-2; Additional Procedures, Battery Verification p. 2 and Reset/Interrupt pp. 6-7; Upgrades pp. 9-12; Exploded View.
- ↑ 3.0 3.1 3.2 3.3 Macintosh Quadra 650 Specs, EveryMac.com—link(accessed 2026-09-30)
- ↑ 4.0 4.1 4.2 Apple Computer, Macintosh Centris 610, Centris 650 and Macintosh Quadra 800 Developer Note (1993), hosted as File:Macintosh Centris 610 Centris 650 and Quadra 800 Developer Note.pdf (see Macintosh Centris 610 Centris 650 and Quadra 800 Developer Note), p. 9 (power supplies) and p. 21 (RAM configurations).
- ↑ 5.0 5.1 Quadra 650: Technical Specifications (Power Macintosh Upgrade Card configuration), Apple—link(accessed 2026-09-30)
- ↑ Apple Macintosh Quadra 650, Retro Viator, 2021-09-02—link(accessed 2026-09-30)