Macintosh Quadra
Encyclopedia
The Macintosh Quadra series was Apple Computer
Apple Computer
Apple Inc. is an American multinational corporation that designs and markets consumer electronics, computer software, and personal computers. The company's best-known hardware products include the Macintosh line of computers, the iPod, the iPhone and the iPad...

's product family of professional high-end Apple Macintosh personal computer
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...

s built using the Motorola 68040
Motorola 68040
The Motorola 68040 is a microprocessor from Motorola, released in 1990. It is the successor to the 68030 and is followed by the 68060. There was no 68050. In keeping with general Motorola naming, the 68040 is often referred to as simply the '040 ....

 CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...

. The first two models in the Quadra line were introduced in 1991, and the name was used until the Power Mac was introduced in 1994. The product manager for the Quadra family was Frank Casanova who was also the Product Manager for the Macintosh IIfx
Macintosh IIfx
The Macintosh IIfx was a model of Apple Macintosh computer, introduced in 1990 and discontinued in 1992. At introduction it cost from US $9,000 to US $12,000, depending on configuration, and was the fastest Mac...

. The first models were the Quadra 700 and Quadra 900, both introduced in 1991. The Quadra replaced the Macintosh II series
Macintosh II series
The Macintosh II series was a series of personal computers in Apple's Macintosh line.-Features:Unlike prior Macintosh models, which were all compact Macintosh designs, the Macintosh II models were "modular" systems which did not include built-in monitors and were expandable...

 as the high end computer in the Macintosh product line.

Models

The first computers to be part of the Macintosh Quadra series were the Quadra 700 and Quadra 900, both introduced in 1991 with a Central processing unit
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...

 (CPU) speed of 25 MHz. The 700 was a compact model using the same case dimensions as the Macintosh IIci
Macintosh IIci
The Apple Macintosh IIci was an improvement on the Macintosh IIcx. Sharing the same compact case design with three expansion slots, the IIci improved upon the IIcx's 16 MHz Motorola 68030 CPU and 68882 FPU, replacing them with 25 MHz versions of these chips. The IIci came with either a 40 or...

, with a Processor Direct Slot
Processor Direct Slot
Processor Direct Slot or PDS introduced by Apple Computer, in several of their Macintosh models, provided a limited measure of hardware expandibility, without going to the expense of providing full-fledged bus expansion slots.Typically, a machine would feature multiple bus expansions slots, if any...

 (PDS) expansion slot, while the latter was a newly designed tower case with five NuBus
NuBus
NuBus is a 32-bit parallel computer bus, originally developed at MIT as a part of the NuMachine workstation project. The first complete implementation of the NuBus and the NuMachine was done by Western Digital for their NuMachine, and for the Lisp Machines Inc. LMI-Lambda. The NuBus was later...

 expansion slots and one PDS slot. The 900 was replaced in 1992 with the Quadra 950, with a CPU speed of 33 MHz. The line was joined by a number of "800-series" machines in a new minitower case design, starting with the Quadra 800, and the "600-series" pizza box
Pizza box form factor
In computing, a pizza box is a style of case for computers or network switches. Cases of this type tend to be wide and flat, normally one or two rack units in height, thus resembling pizza delivery boxes....

 desktop cases with the Quadra 610.

In 1993 the Quadra AV series was released, consisting of the 800-series Quadra 840AV and the 600-series Quadra 660AV, at 40 MHz and 25 MHz respectively. Both included an AT&T
AT&T
AT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...

 Digital signal processor
Digital signal processor
A digital signal processor is a specialized microprocessor with an architecture optimized for the fast operational needs of digital signal processing.-Typical characteristics:...

 and S-Video
S-Video
Separate Video, more commonly known as S-Video and Y/C, is often referred to by JVC as both an S-VHS connector and as Super Video. It is an analog video transmission scheme, in which video information is encoded on two channels: luma and chroma...

 and composite video
Composite video
Composite video is the format of an analog television signal before it is combined with a sound signal and modulated onto an RF carrier. In contrast to component video it contains all required video information, including colors in a single line-level signal...

 input and output ports for video, as well as CD
Compact Disc
The Compact Disc is an optical disc used to store digital data. It was originally developed to store and playback sound recordings exclusively, but later expanded to encompass data storage , write-once audio and data storage , rewritable media , Video Compact Discs , Super Video Compact Discs ,...

-quality microphone
Microphone
A microphone is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. In 1877, Emile Berliner invented the first microphone used as a telephone voice transmitter...

 and audio output ports. The AV models also introduced PlainTalk, consisting of the text-to-speech software MacinTalk Pro and speech control (although not dictation). However all of these features were poorly supported in software, and DSP was not installed in later AV Macs.

Branding

Apple hired marketing firm Lexicon Branding
Lexicon Branding
Lexicon Branding, Inc., is an American marketing firm founded in 1982 by David Placek. It focuses on selecting brand names for companies and products...

 to come up with the name. Lexicon chose the name Quadra hoping to appeal to engineers by evoking technical terms like quadrant and quadriceps.

The Quadra name was also used for the successors to the Centris
Macintosh Centris
Macintosh Centris is a line of Macintosh computers, introduced in 1993, that were built around the Motorola 68LC040 and 68040 CPUs. The name was chosen to indicate that the consumer was selecting a Macintosh in the center of Apple's product line: lower performance than the Quadra computers, but...

 models that briefly existed during 1993: The 610
Macintosh Quadra 610
The Macintosh Quadra 610 and Macintosh Centris 610 are two closely related personal computers that are a part of Apple Computer's Quadra and Centris series of Macintosh computers, respectively. When the Centris 610 was introduced in February 1993 alongside the larger Centris 650, it was intended as...

, the 650
Macintosh Quadra 650
The Macintosh Quadra 650 and the Macintosh Centris 650 are two closely related personal computers that are a part of Apple Computer's Quadra and Centris series of Macintosh computers, respectively...

 and the 660AV
Macintosh Quadra 660AV
The Macintosh Quadra 660AV is a personal computer that is a part of Apple Computer's Quadra series of Macintosh computers. When it was originally introduced in July 1993 alongside the Quadra 840 AV it was called the Macintosh Centris 660AV, but it was renamed without any major changes in the...

. Centris was a "mid-range" series of systems between the Quadra on the high end and the LC
Macintosh LC
The Macintosh LC was Apple Computer's product family of low-end consumer Macintosh personal computers in the early 1990s. The original Macintosh LC was released in 1990 and was the first affordable color-capable Macintosh. Due to its affordability and Apple II compatibility the LC was adopted...

 on the low end, but it was later decided that there were too many product lines and the name was dropped. Some machines of this era including the Quadra 605 were also sold as Performas
Macintosh Performa
The Macintosh Performa series was Apple Computer's consumer product family of Apple Macintosh personal computers sold through department stores and mass-market retailers from 1992 until 1997, when it was superseded by the Power Macintosh 5x00 series...

, further adding to the confusion.

The last use of the name was for the Quadra 630, which was a variation of the LC 630 using a "full" Motorola 68040
Motorola 68040
The Motorola 68040 is a microprocessor from Motorola, released in 1990. It is the successor to the 68030 and is followed by the 68060. There was no 68050. In keeping with general Motorola naming, the 68040 is often referred to as simply the '040 ....

 instead of the LC's 68LC040, and introduced together with it in 1994. The 630 was the first Mac to use an IDE based drive bus for the internal hard disk
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...

 drive, whereas all earlier models had used SCSI
SCSI
Small Computer System Interface is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it...

.

The first three Apple Workgroup Server
Apple Workgroup Server
Apple Workgroup Server and, later, Macintosh Server, were the names given to selected models of Macintosh computers which were sold by Apple Computer with additional server software and sometimes bigger hard drives. Apart from that, they were mostly identical to computers out of Apple's...

 models, the WGS 60, the WGS 80 and the WGS 95 (mostly called "AWS 95" for "Apple Workgroup Server") were based on the Centris 610, the Quadra 800 and the Quadra 950, respectively.
Processor
The transition to the Motorola 68040 was not as smooth as the previous transitions to the Motorola 68020
Motorola 68020
The Motorola 68020 is a 32-bit microprocessor from Motorola, released in 1984. It is the successor to the Motorola 68010 and is succeeded by the Motorola 68030...

 or Motorola 68030
Motorola 68030
The Motorola 68030 is a 32-bit microprocessor in Motorola's 68000 family. It was released in 1987. The 68030 was the successor to the Motorola 68020, and was followed by the Motorola 68040. In keeping with general Motorola naming, this CPU is often referred to as the 030 .The 68030 features on-chip...

. Due to the Motorola 68040's split instruction and data caches, the Quadra had compatibility problems with self-modifying code
Self-modifying code
In computer science, self-modifying code is code that alters its own instructions while it is executing - usually to reduce the instruction path length and improve performance or simply to reduce otherwise repetitively similar code, thus simplifying maintenance...

 (including relocating code, which was common under the Macintosh memory model
Mac OS memory management
Historically, the Mac OS used a form of memory management that has fallen out of favour in modern systems. Criticism of this approach was one of the key areas addressed by the change to Mac OS X....

). 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. 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).
See also



External links
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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