TheMacintosh Quadra is a family ofpersonal computers designed, manufactured and sold byApple Computer, Inc. from October 1991 to October 1995. The Quadra, named for theMotorola 68040central processing unit, replaced theMacintosh II family as the high-endMacintosh model.
The first models were theQuadra 700 andQuadra 900, both introduced in October 1991, with the latter discontinued after six months and replaced by theQuadra 950. TheQuadra 800 was added in February 1993 (succeeding the Quadra 700), followed the multimedia-focused840AV at the end of July 1993. TheMacintosh Centris line was merged with the Quadra in October 1993, adding the610,650 and660AV to the range. The605 (also sold as the Performa 475 or LC 475) was also introduced in October 1993, featuring the 68LC040 (lacking an FPU) as standard although it could be upgraded to the full 68040. After the introduction of thePower Macintosh line in early 1994, theQuadra 630 (using the "full"Motorola 68040 instead of the LC's68LC040) became the last new Quadra member. The Quadra 950 continued to be sold until October 1995.
The product manager for the Quadra family was Frank Casanova who was also the Product Manager for theMacintosh IIfx.
The first computers bearing the Macintosh Quadra name were theQuadra 700 andQuadra 900, both introduced in 1991 with acentral processing unit (CPU) speed of 25MHz. The 700 featured identical case dimensions as theMacintosh IIci but vertically oriented as a mini-tower, with aProcessor Direct Slot (PDS) expansion slot, while the latter was a newly designedfull-tower case with fiveNuBus expansion slots and one PDS slot. The 900 was replaced in 1992 with the very similarQuadra 950, with a faster CPU speed of 33 MHz and improved graphics support.
TheQuadra 800 was added in February 1993. It was positioned below the flagship Quadra 950 and succeeded the Quadra 700 (which was discontinued shortly after the Quadra 800's announcement). Debuting at half the price of the Quadra 950, the Quadra 800 featured the sameMotorola 68040 33 MHz processor as the 950 but its additionalinterleavedRAM running at 70 ns, as well as an enhanced video system andSCSI bus, enabled it to outperform the 950.[1] The Quadra 800'smid-tower case had four drive bays, giving it more expansion options than the Quadra 700's mini-tower, while having a form factor still considerably shorter than the Quadra 900/950's full tower.[2]
In July 1993, theQuadra 840AV and660AV (originally branded as Centris 660AV) were introduced at 40 MHz and 25 MHz respectively. They included anAT&T 3210Digital signal processor andS-Video andcomposite video input/output ports, as well asCD-qualitymicrophone and audio output ports.[3] The AV models also introducedPlainTalk, consisting of the text-to-speech softwareMacinTalk Pro and speech control (although not dictation). However, all of these features were poorly supported in software and a DSP was not installed in later AV Macs, which were based on the more powerfulPowerPC 601 - a CPU powerful enough to handle the coprocessor's duties on its own.[4]
The Quadra name was also used for the successors to theCentris models that briefly existed during 1993: the610, the650 and the660AV. Centris was a "mid-range" line of systems (featuring slower 68040 CPUs, often the 68LC040 which omits the FPU), between the existing Quadra on the high end (featuring the faster 68040 CPU) and theLC on the low end (built around the 68030 CPU), but it was later decided that there were too many product lines and so Centris was dropped in October 1993.
The605 (also sold as the Performa 475 or LC 475) was also introduced in October 1993, featuring the 68LC040 as standard although it could be upgraded to the full 68040. At that point, the Quadra lineup consisted of the 950 using a full tower case, the "800-series" machines with aMid-tower case design (Quadra 800 and840AV), and the "600-series" (theQuadra 605,Quadra 610 and660AV hadpizza box desktop cases, while the Quadra 650 had a taller desktop case).
After thePower Macintosh line was launched in early 1994, only one more member of the Quadra family was released which was in July 1994, theQuadra 630, which was a variation of the LC 630 using a "full"Motorola 68040 instead of the LC's68LC040, and introduced together with it in 1994. The 630 was the first Mac to use anIDE based drive bus for the internalhard disk drive, whereas all earlier models had usedSCSI. All of the other Quadra models introduced in 1993 would be discontinued in 1994 after being available for sale for a year, to be replaced by Power Macintosh models, except for the Quadra 950 which continued to be sold until October 1995.
Apple hired marketing firm Lexicon Branding to come up with the name. Lexicon chose the name Quadra hoping to appeal to engineers by evoking technical terms like quadrant and quadriceps.[5]
The first threeApple Workgroup Server models, the WGS 60, the WGS 80 and the WGS 95 (mostly called "AWS 95" for "Apple Workgroup Server") were based on the Quadra 610 (originally Centris 610), the Quadra 800 and the Quadra 950, respectively.
In October 1993, to keep pace with the growing number of relatively affordableIBM compatibles powered by theIntel 80486, Apple introduced or rebranded numerous "entry-level" Quadra models (particularly the 605, 610, and later 630) for home or education use with their 68LC040 CPU, in comparison to the original models (700, 800/840AV, 900/950) which were positioned as high-end workstations due to their 68040 CPU and higher RAM ceilings. These low-end models arguably devaluated the Quadra branding, as the "600-series" also featured the higher-end models 650 and 660AV that more faithful to the original Quadra family (despite being rebranded from Centris). Furthermore the 605 and 630 were sold under the LC and Performa labels which created further confusion among consumers, whereas the more expensive Quadra models did not have an alternative branding.[6] Ultimately, the Quadra family's demise was hastened as models were succeeded by thePower Macintosh, the latter family aiming to compete with IBM compatibles powered by thePentium (P5).
The transition to the Motorola 68040 was not as smooth as the previous transitions to theMotorola 68020 orMotorola 68030. Due to the Motorola 68040's split instruction and data caches, the Quadra had compatibility problems withself-modifying code (including relocating code, which was common under theMacintosh memory model). Apple partially fixed this by having the basic Mac OS memory copy call flush the caches. This solved the vast majority of stability problems, but negated much of the Motorola 68040's performance improvements. Apple also introduced a variant of the memory copy call that did not flush the cache.[7] The new trap was defined in such a way that calling it on an older version of Mac OS would simply call the previous memory copy routine. The net effect of this was that many complex applications were initially slow or prone to crashing on the 68040, although developers quickly adapted to the new architecture by relying on Apple's memory copy routines rather than their own (or flushing the cache) and using the memory copy that did not flush the cache when appropriate (most of the time).
According to Apple, all of these models are obsolete.[a][8]
| Model | Quadra 700[9][10] | Quadra 900[11][12] | Quadra 950[13][14] | Quadra 800[15][16] | Quadra 650[17][18] (Centris 650) | Quadra 610[19][20] (Centris 610) | Quadra 660AV[21][22] (Centris 660AV) | Quadra 840AV[23][24] | Quadra 605[25][26] (LC 475,Performa 475,Performa 476) | Quadra / LC / Performa 630[27][28] | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Timetable | Predecessor | IIci | IIfx | Quadra 900 | Quadra 700 | IIvi/vx | IIsi | None | Quadra 950 &Quadra 800 | LC III | Quadra 610 |
| Released | October 21, 1991 | May 18, 1992 | February 9, 1993 | February 10, 1993 | July 29, 1993 | October 21, 1993 | July 15, 1994 | ||||
| Discontinued | March 15, 1993 | May 18, 1992 | October 14, 1995 | March 14, 1994 | September 12, 1994 | July 18, 1994 | September 12, 1994 | July 18, 1994 | October 17, 1994 | October 5, 1995 | |
| Successor | Centris 650 &Quadra 800 | Quadra 950 | Power Macintosh 9500 | Quadra 840AV &Power Macintosh 8100 | Quadra 630 &Power Macintosh 6100/60AV | Quadra 630 &Quadra 660AV &Power Macintosh 6100 | Power Macintosh 8100/80AV | Power Macintosh 7100/66AV &Power Macintosh 8100/80AV | LC 520 | Power Macintosh 6300 | |
| Model | Marketing model no. | M5921 | M4210 | M6710 | M1287 | M2107 | M2372 | M2691 | M9025 | M1821 | M3491 |
| Model number | M5920 | M4200 | M4300 | M1206 | M2118 | M2113 | M9040 | M9020 | M1476 | M3076 | |
| Gestalt ID | 22 | 20 | 26 | 35 | 36 | 53 | 60 | 78 | 89 | 98 | |
| Enclosure | Macintosh IIcx tower/desktop | Mac Quadra 900 tower | Mac Quadra 800 tower | Mac IIvx desktop | Mac Centris 610 desktop | Mac Quadra 800 tower | Mac Quadra 605 desktop | Mac Quadra 630 desktop | |||
| Performance | Processor | 25 MHz Motorola 68040[29] | 25 MHz Motorola 68040 | 33 MHz Motorola 68040 (25 MHzMotorola 68LC040 or68040 for Centris 650) | 25 MHz Motorola 68040 (20 MHzMotorola 68LC040 for Centris 610) | 40 MHz Motorola 68040 | 25 MHz Motorola 68LC040 | 33 MHz Motorola 68040 (Motorola 68LC040 for LC and Performa) | |||
| Memory | 4MB(expandable to 68 MB) | 4 MB(expandable to 256 MB) | 8 MB(expandable to 256 MB) | 8 MB(expandable to 136 MB) | 4 MB(expandable to 132 MB) or 8 MB(expandable to 136 MB) | 4 MB(expandable to 68 MB) | 8 MB(expandable to 68 MB) | 8 or 16 MB(expandable to 128 MB) | 4 or 8 MB(expandable to 36 MB) | 4 MB(expandable to 36 MB) | |
| 4 x 80 ns 30-pin SIMM | 16 x 80 ns 30-pin SIMM | 4 x 60 ns 72-pin SIMM | 1 x 80 ns 72-pin SIMM | 2 x 80 ns 72-pin SIMM | 2 x 70 ns 72-pin SIMM | 4 x 60 ns 72-pin SIMM | 1 x 80 ns 72-pin SIMM | ||||
| Video card | 512 KB – 2 MB 6 x 100 ns VRAM SIMM slots | 1 MB – 2 MB 6 x 100 ns VRAM SIMM slots | 1 MB – 2MB 4 x 80 ns VRAM SIMM slots | 512 KB – 1MB 2 x 80 ns VRAM SIMM slots | 512 KB – 1MB 2 x 100 ns VRAM SIMM slots | 1 MB 1 x 80 ns VRAM SIMM slot | 1 MB – 2 MB 4 x 80 ns VRAM SIMM slots | 512 KB – 1 MB 2 x 80 ns VRAM SIMM slots | 1 MB 1 x 60 ns VRAM SIMM slot | ||
| Storage | Hard drive | 0, 80, 160 or 400 MB (SCSI) | 0, 160 or 400 MB (SCSI) | 230, 400 MB, or 1 GB (SCSI) | 230 or 500 MB (SCSI) | 160 or 230 MB (SCSI) | 230 or 500 MB (SCSI) | 230, 500 MB, or 1 GB (SCSI) | 80 or 160 MB (SCSI) | 250 MB (IDE) | |
| Optical drive | None | None (Optional 2x CD-ROM) | None | None (Optional 2x CD-ROM) | |||||||
| Ports | 2 x ADB 2 x DIN-8 RS-422 SCSI DB-25 | ||||||||||
| Operating system | Minimum | System 7.0.1 A/UX | System 7.0.1 | System 7.1 | System 7.1.2P | ||||||
| Maximum | Mac OS 8.1 Mac OS 9.1 (with PowerPC upgrade) | ||||||||||
| Timeline ofMacintosh Centris,LC,Performa, andQuadra models, colored byCPU type |
|---|
 See also:List of Mac models |
