Tips and Information

2007-06-22T09:04:00.002-07:00

History

Main article: History of Apple Inc.

The company introduced the Apple II microcomputer in 1977. A few years later, in 1983, it introduced the Lisa, the first commercial personal computer to employ a graphical user interface (GUI), which was influenced in part by the Xerox Alto. Lisa was also the first personal computer to have the mouse. In 1984, the Macintosh was introduced, which arguably advanced the concept of a user-friendly graphical user interface. Apple's success with the Macintosh became a major influence in the development of graphical interfaces elsewhere, with major computer operating systems, such as Commodore Amiga, and Atari ST, appearing on the market within two years of the introduction of the Macintosh.

In 1991, Apple introduced the PowerBook line of portable computers. The 1990s also saw Apple's market share fall as competition from Microsoft Windows and the comparatively inexpensive IBM PC compatible computers that would eventually dominate the market. In the 2000s, Apple expanded its focus on software to include professional and prosumer video, music, and photo production solutions, with a view to promoting their products as a "digital hub". It also introduced the iPod, the most popular digital music player in the world.^[9]

[edit] 1976 to 1980: The early years

The Apple I, Apple's first product. Sold as an assembled circuit board, it lacked basic features such as a keyboard, monitor and case. The owner of this unit added a keyboard and a wooden case.

Apple was founded on April 1, 1976 by Steve Jobs, Steve Wozniak, and Ronald Wayne^[10] (and later incorporated January 3, 1977^[11] without Wayne, who sold his share of the company back to Jobs and Wozniak) to sell the Apple I personal computer kit. They were hand-built by Steve Wozniak[2][3] in a garage of Jobs' parents, and the Apple I was first shown to the public at the Homebrew Computer Club.^[12] Eventually 200 computers were built. The Apple I was sold as a motherboard (with CPU, RAM, and basic textual-video chips) — not what is today considered a complete personal computer.^[13] The user was required to provide two different AC input voltages (the manual recommended specific transformers), wire an ASCII keyboard (not provided with the computer) to a DIP connector (providing logic inverter and alpha lock chips in some cases), and to wire the video output pins to a monitor or to an RF modulator if a TV set was used.

Jobs approached a local computer store, The Byte Shop, which ordered fifty units and paid US$500 for each unit after much persuasion from Jobs. He then ordered components from Cramer Electronics, a national electronic parts distributor. Using a variety of methods, including borrowing space from friends and family and selling various items including a Volkswagen Type 2 bus, Jobs managed to secure the parts needed while Wozniak and Ronald Wayne assembled the Apple I.^[14]

The Apple II was introduced on April 16, 1977 at the first West Coast Computer Faire. Despite a price higher than competitors, it quickly pulled away from its two main rivals, the TRS-80 and Commodore PET, to become the market leader (and the symbol of the personal computing phenomenon) in the late 70s due to its color graphics, high build quality, and open architecture. While early models used ordinary cassette tapes as storage devices, this was quickly superseded by the introduction of a 5 1/4 inch floppy disk drive and interface, the Disk II.

Another key to business for Apple was software. The Apple II was chosen by programmers Dan Bricklin and Bob Frankston to be the desktop platform for the first "killer app" of the business world—the VisiCalc spreadsheet program.^[15] VisiCalc created a business market for the Apple II, and the corporate market attracted many more software and hardware developers to the machine, as well as giving home users an additional reason to buy one—compatibility with the office.^[15] (See the timeline for dates of Apple II family model releases—the 1977 Apple II and its younger siblings the II+, IIe, IIc, and IIGS.)

According to Brian Bagnall's book, "On the Edge" (pg. 109-112), Apple exaggerated their sales figures and that Apple was a distant 3rd place until VisiCalc came along. VisiCalc was first released on Apple II because Commodore and Tandy computers were tied up in VisiCalc's software development office due to their popularity. VisiCalc's association with Apple was thus pure happenstance, not a technical decision. And even after VisiCalc, Apple II didn't surpass Tandy TRS-80, whose sales were helped by the large number of Radio Shack stores. However, VisiCalc did put Apple ahead of Commodore's PET, at least in the US. (Commodore later regained the lead for a while with the Commodore 64 in the mid 80s, the best selling specific model of computer to date.)^[16]

By the end of the 1970s, Jobs and his partners had a staff of computer designers and a production line. The Apple II was succeeded by the Apple III in May 1980 as the company struggled to compete against IBM and Microsoft in the lucrative business and corporate computing market. The designers of the Apple III were forced to comply with Jobs' request to omit the cooling fan, and this ultimately resulted in thousands of recalled units due to overheating.^[17] An updated version was introduced in 1983, but it was also a failure due to bad press and wary buyers.

In the early 1980s, IBM and Microsoft continued to gain market share at Apple's expense in the personal computer industry. A fundamentally different business model evolved, once cloners forced-open the IBM PC hardware standard against IBM's will. The IBM compatible hardware market became highly competitive, with clones running a bundled Microsoft MS-DOS OS, or running a competing IBM-style DOS such as DR DOS.

Apple's sustained growth during the early 1980s was partly due to its leadership in the education sector, attributed to their adaption of the programming language LOGO, used in many schools with the Apple II. The drive into education was accentuated in California with the donation of one Apple II and one Apple LOGO software package to each public school in the state. The deal concluded between Steve Jobs and Jim Baroux of LCSI, and having required the support of Sacramento, established a strong and pervasive presence for Apple in all schools throughout California. The initial conquest of education environments was critical to Apple's acceptance in the home where the earliest purchases of computers by parents was in support of children's continued learning experience.

[edit] 1981 to 1989: Lisa and Macintosh

The rebel from Apple's 1984 ad, set in a dystopian future modeled after the Orwell novel Nineteen Eighty-Four, set the tone for the introduction of the Macintosh

Jobs and several other Apple employees including Jef Raskin visited Xerox PARC in December 1979 to see the Alto computer. Xerox granted Apple engineers three days of access to the PARC facilities in return for selling them US$1 million in pre-IPO Apple stock (approximately US$18 million net).

It is said that Jobs was immediately convinced that all future computers would use a GUI, and decided to take over design of Apple's first project, the Apple Lisa, to produce such a device. The Lisa was named after Jobs' daughter (however, a backronym,^[18] Local Integrated Software Architecture, was coined). He was eventually pushed from the group due to infighting, and instead took over Jef Raskin's low-cost computer project, the Macintosh. Branding the new effort as the product that would "save Apple", an intense turf war broke out between the Lisa's "corporate shirts" and Jobs' Macintosh "pirates", both teams claiming they would ship first and be more successful. In 1983 the Lisa team won the race and Apple introduced the first personal computer to be sold to the public with a GUI. However, the Lisa was a commercial failure as a result of its high price tag (US$9,995) and limited software titles.^[18]

In 1984, drawing upon its experience with the Lisa, Apple next launched the Macintosh. Its debut was announced by a single national broadcast of the now famous US$1.5 million television commercial, "1984", based on George Orwell's novel Nineteen Eighty-Four. The commercial was directed by Ridley Scott and aired during Super Bowl XVIII on January 22, 1984. Jobs' intention with the ad was to represent the IBM PC as Big Brother, and the Macintosh as a nameless female action hero portrayed by Anya Major. While the Macintosh initially sold well, follow-up sales were not particularly strong.^[19] The machine's fortunes changed with the introduction of the LaserWriter, the first laser printer to be offered at a reasonable price point, and PageMaker, an early desktop publishing (DTP) package. The Mac was particularly powerful in this market due to its advanced graphics capabilities, which were already necessarily built-in to create the Macintosh GUI. It has been suggested that the combination of these three products was responsible for the creation of the DTP market.^[20] As DTP became widespread, Apple's sales reached a series of new highs.

In anticipation of the Macintosh launch, Bill Gates, co-founder and chairman of Microsoft, was given several Macintosh prototypes in 1983 to develop software. While the company was indeed ready with its BASIC and the MultiPlan spreadsheet at the Macintosh's launch,^[19] in 1985 Microsoft launched Windows, its own GUI for IBM PCs. Although sales started slow, by the mid 1990s it became the most commonly-used desktop operating system, cutting deeply into the Macintosh's sales.

An internal power struggle developed between Jobs and new CEO John Sculley in 1985.^[21] Apple's board of directors sided with Sculley and Jobs was removed from his managerial duties.^[19] Jobs later resigned from Apple and founded NeXT Inc., a computer company that built machines with futuristic designs and ran the UNIX-derived NeXTStep operating system. Although powerful, NeXT computers never caught on with buyers, due in part to their high purchase price.

[edit] 1989 to 1991: The Golden Age

The Macintosh Portable was Apple's first "portable" Macintosh computer, released in 1989.

Having learned several painful lessons after introducing the bulky Macintosh Portable in 1989, Apple turned to industrial designers and adopted a product strategy based in three portable devices. One portable was built by Sony, which had a strong reputation for designing small, durable and functional electronics devices. Sony took the specs of the Mac Portable, put in a smaller two-hour battery, a much smaller (physically) 20 MB hard drive and a smaller nine-inch passive matrix screen.^[22]

Called the PowerBook 100, this landmark product was introduced in 1991 and established the modern form and ergonomic layout of the laptop computer.^[22] This solidified Apple's reputation as a quality manufacturer, both of desktop and now portable machines.^[23] The same year, Apple introduced a massive upgrade to the Mac OS, in the form of System 7. Although resource-hungry (for the era), System 7 dramatically improved the Macintosh experience, adding color to the interface, simplifying common operations, and introducing a number of powerful new networking capabilities. System 7 would be the basis for the Mac OS until 2001.

The success of the PowerBook and several other Apple products during this period led to increasing revenue.^[21] The computer press listened to Apple press releases with rapt attention and speculation was rife about what projects from Apple's famed Advanced Technology Group would next come to market. Apple merely had to mention a technology, Taligent for instance, for people to christen it the "new standard".^[24] For some time, it appeared that Apple could do no wrong, introducing fresh new products and generating increasing profits in the process. The magazine MacAddict named the period between 1989 to 1991 the "first golden age" of the Macintosh.

The continuing development of Microsoft Windows had given birth to an interface that was competitive with Apple's. Combined with a huge base of low-cost computers and peripherals and an improving software suite, an increasing number of potential customers turned to the "Wintel" standard.

Apple, relying on high profit margins to maintain their massive R&D budget, never developed a clear response. Instead they sued Microsoft for theft of intellectual property.^[25] The lawsuit dragged on for years before finally being thrown out of court. Worse, the lawsuit distracted management while a deep rot developed within the engineering ranks, which became increasingly unmanageable. At first there was little outward sign of the problem, but a series of major product flops and missed deadlines destroyed Apple's reputation of invincibility.

At about the same time, Apple branched out into consumer electronics. One example of this product diversification was the Apple QuickTake digital camera, one of the first digital cameras brought to the consumer market. A more famous example was the Newton, coined a PDA by Sculley, that was introduced in 1993. Though it failed commercially, it defined and launched a new category of computing and was a forerunner of devices such as Palm Pilot and PocketPC.

During the 1990s, Apple greatly expanded its computer lineup. It offered a multitude of models ("Quadra 840av", "Performa 6116"), but many felt Apple failed to adequately differentiate one model from another and the cost of supporting so many products adversely affected profitability. Apple lost market share to Microsoft Windows, particularly Windows 95 — a major turning point in the history of the rival Windows operating system.

[edit] 1994 to 1997: Attempts at reinvention

The Apple Newton was Apple's first foray into the PDA markets, as well as one of the first in the industry. A financial flop, it helped pave way for the Palm Pilot and Apple's own iPhone in the future.

By the mid-90s, Apple realized that it had to reinvent the Macintosh in order to stay competitive in the market. The needs of both computer users and computer programs were becoming, for a variety of technical reasons, harder for the existing hardware and operating system to address.

In 1994 Apple surprised its loyalists by allying with its long-time competitor IBM and CPU maker Motorola in the so-called AIM alliance. This was a bid to create a new computing platform (the PowerPC Reference Platform or PReP), which would use IBM and Motorola hardware coupled with Apple's software. The AIM alliance hoped that PReP's performance and Apple's software would leave the PC far behind, thus countering Microsoft, which had become Apple's chief competitor.

As the first step toward launching the PReP platform, Apple started the Power Macintosh line in 1994, using IBM's PowerPC processor. This processor utilized a RISC architecture, which differed substantially from the Motorola 68k series that had been used by all previous Macs. Apple's OS was rewritten so that most software for the older Macs could run on the PowerPC series (in emulation).

Throughout the mid to late 1990s, Apple tried to improve its operating system's multitasking and memory management. After first attempting to modify its existing code, Apple realized that it would be better to start with an entirely new operating system and then modify it to fit the Macintosh interface. Apple did some preliminary work with IBM towards this goal with the Taligent project, but that project never produced a replacement operating system. A new internal effort, Copland, ran afoul of Apple's now uncontrollable engineering and became a massive failure. A fresh attempt was made with the Gershwin operating system.

In 1995 Apple made a break into the gaming industry with the Apple Pippin. Despite the success of competing game consoles like Sony PlayStation, Nintendo 64, and Sega Saturn, Pippin experienced very limited success and as little as 5000 units were sold worldwide^[26] and there was a very small variety of games available for those who did own a console. Overall this was a failure for Apple; its scope was more general in purpose than serious gaming, leaving the console expensive and underpowered compared with its rivals.

Next, the company considered its options for an operating system, investigating Be Inc.'s BeOS, NeXT's NeXTSTEP OS, and also Microsoft's Windows NT. NeXTSTEP was chosen, and this supplied the platform for the modern Mac OS X. On February 7, 1997, Apple completed its purchase of NeXT and its NeXTSTEP operating system, in the process bringing Steve Jobs back into Apple.^[27] On July 9, 1997, Gil Amelio was ousted as CEO of Apple by the board of directors after overseeing a 12-year record-low stock price and crippling financial losses. Jobs stepped in as the interim CEO and began a critical restructuring of the company's product line.

At the 1997 Macworld Expo, Steve Jobs announced that Apple would be entering into partnership with Microsoft. Settlement discussions regarding Apple's "Look and Feel" lawsuit and the "QuickTime piracy" lawsuit resulted in a five-year commitment from Microsoft to release Microsoft Office for Macintosh as well as a US$150 million investment in non-voting Apple stock. (This event is often inaccurately described as a "bailout" of Apple by Microsoft. At the time Apple had a little over US$1 billion in cash and cash equivalents according to their 10-Q statement.^[28] Microsoft later sold its shares for a tidy profit.) Jobs also announced that Internet Explorer would be shipped as the default browser on the Macintosh. Microsoft chairman Bill Gates appeared at the expo on the large screen, explaining Microsoft's plans for the software they were developing for the Macintosh, and saying that he was very excited to be helping Apple. This was met with a less than positive response from the audience. Steve Jobs said:

If we want to move forward and see Apple healthy and prospering again, we have to let go of a few things here. We have to let go of this notion that for Apple to win, Microsoft has to lose. We have to embrace a notion that for Apple to win, Apple needs to do a really good job. And if others are going to help us that's great, because we need all the help we can get, and if we screw up and don't do a good job, it's not somebody else's fault, it's our fault. So I think that is a very important perspective. If we want Microsoft Office on the Mac, we should treat the company that puts it out with a little bit of gratitude; we like their software. So, the era of setting this thing up as a competition between Apple and Microsoft is over as far as I'm concerned. This is about getting Apple healthy, this is about Apple being able to make incredibly great contributions to the industry and to get healthy and prosper again.^[29]

On November 10, 1997, Apple announced a new online retail store, based upon the WebObjects application server the company had acquired in its purchase of NeXT. The new direct sales outlet was also tied to a new build-to-order manufacturing strategy and announced at the same time as new machines using the G3 PowerPC processor.

[edit] 1998 to 2005: New beginnings

Steve Jobs introducing the original iMac computer in 1998.

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On August 15, 1998, Apple introduced a new all-in-one Mac computer reminiscent of the original Macintosh 128K: the iMac. The iMac design team was led by Jonathan Ive, who would come later to design the iPod and the iPhone.^[30]^[31] While technically unimpressive, it featured an innovative new translucent plastic exterior, originally in Bondi Blue, but later many other colors. The iMac proved phenomenally successful, selling close to 800,000 units in its first five months and significantly boosting the company's revenue and profitability. Thanks in part to the iMac, fiscal 1998 was Apple's first profitable year since 1993. Some consider the iMac an industrial design icon of the late 90s, and its designer, Jonathan Ive has won awards for its innovation.^[32]

At the National Association of Broadcasters convention, Apple purchased the Final Cut software from Macromedia, beginning its entry into the digital video editing market, and signaling a return to application development after a decade long policy of delegating non-system software to its Claris subsidiary. iMovie was released in 1999 for consumers, and Final Cut Pro was released for professionals in the same year. Final Cut Pro has gone on to be a significant video-editing program. Similarly, in 2000 Apple bought Astarte's DVDirector software, which morphed into iDVD (for consumers) and DVD Studio Pro (for professionals) at the Macworld Conference and Expo of 2001.

In 2001, Apple introduced Mac OS X, the operating system based on NeXT's OPENSTEP and BSD Unix. Aimed at consumers and professionals alike, Mac OS X aimed to marry the stability, reliability and security of the Unix operating system with the ease of use afforded by a completely overhauled user interface. To aid users in moving their applications from Mac OS 9, the new operating system allowed the use of OS 9 applications through Mac OS X's Classic environment. Apple's Carbon API also allowed developers to adapt their OS 9 software to use Mac OS X's features often with a simple recompile.

Company headquarters on Infinite Loop in Cupertino, California.

On May 19, 2001, after much speculation, Apple announced the opening of the first official Apple retail stores, to be located in major U.S. consumer locations. These stores were designed for two purposes: to stem the tide of Apple's declining share of the computer market and to counter a poor record of marketing Apple products by third-party retail outlets. The company faced challenges to balance the deployment of its own retail stores with its dependence on, and the demands of, its existing channel partners and dealers. Apple slowly built up the number of stores in the U.S., (now totaling 150)^[33] later opening stores in Canada, Japan, United Kingdom, and recently Italy. These efforts in retail succeeded and proved to be very profitable, averaging annual returns of US$4,032 per square foot of every store, the most in retail. These returns bested retail favorites such as Best Buy and Tiffany's.^[33]

On October 23, 2001 Apple introduced its first iPod portable digital audio player and released it on November 10 of that year. The product has proven phenomenally successful; over 100 million units have been sold.^[34] Apple's iTunes Store was introduced soon after, offering online music downloads for US 99¢ a song and integration with the iPod. The service quickly became the market leader in online music services, with over 2 billion downloads by January 2007.^[35]

In 2002 Apple purchased Nothing Real and their advanced digital compositing application Shake, raising Apple's professional commitment even higher. In the same year they also acquired Emagic, and with it, obtained their professional-quality music productivity application Logic, which led to the development of their consumer-level GarageBand application. With iPhoto's release in 2002, this completed Apple's collection of consumer and professional level creativity software, with the consumer-level applications being collected together into the iLife suite.

Apple progressively abandoned flashy colors in favor of white polycarbonate for consumer lines such as the iMac and iBook, as well as the educational eMac, and metal enclosures for the professional lines. This began with the 2001 release of the titanium PowerBook and was followed by the 2001 white iBook, the 2002 flat-panel iMac, the 2003 Power Mac G5, and the 2004 Apple Cinema Displays. Divergent to this consumer/professional identity, the low-cost Mac mini has an aluminum case while featuring the distinctive white polycarbonate top.

[edit] 2005 to present: The Intel partnership

Targeted at a professional audience, the MacBook Pro (15.4" widescreen) was Apple's first laptop with an Intel microprocessor. It was announced in January 2006, and hit the shelves around March. The less expensive MacBook (13.3" widescreen) caters to the consumer market.

Main article: Apple Intel transition

In the Worldwide Developers Conference (WWDC) keynote address on June 6, 2005, Steve Jobs officially announced that Apple would begin producing Intel-based Mac computers beginning in 2006.^[36] Jobs confirmed rumors that the company had secretly been producing versions of its current operating system Mac OS X for both PowerPC and Intel processors for the previous five years and that the transition to Intel processor systems would last until the end of 2008.^[37]

On January 10, 2006, Apple released its first Intel chip computers, a new notebook computer known as the MacBook Pro (with a 15.4" screen) and a new (though cosmetically identical) iMac with purportedly two to three times faster performance compared with its predecessor. Both used Intel's Core Duo chip technology. Later in February, Apple introduced the new Intel-based Mac mini, running up to four times faster and also featuring Front Row, available with a Core Duo or Core Solo (single core) processor. The Apple online store sold out of 17" iMac G5 computers in February 2006, Apple ended the life of its 15" PowerBook G4 on February 22, 2006, and the G4 Mac mini was removed from the Apple online store on February 28, 2006 and replaced with the Intel Core Mac mini. On March 10, 2006 Apple retired the iMac G5 and on May 16, 2006, replaced the iBook G4 and the 12" PowerBook G4 with the MacBook. On August 7, 2006, the PowerMac was replaced with the Mac Pro, completing the transition of all Mac computers, well in advance of their original prediction. On September 6, 2006, Apple updated its iMac line to include new Intel Core 2 Duo processors, and adding a model with a 24" screen to the line-up, as well as quietly bumping the speeds of their Mac mini. The XServe was transitioned in mid-November 2006. On October 24, 2006 the MacBook Pros were fitted with Intel Core 2 Duo processors as well, running up to 39% faster than the original Intel Core Duo MacBook Pros. The MacBooks were fitted with the Core 2 Duo processors on November 8, and run up to 25% faster than the Core Duo ones according to Apple's tests.^[38]

Apple's current operating system, Mac OS X v10.4 "Tiger", runs natively on the new Intel machines, as do the Darwin open source underpinnings. Many applications, such as iLife '06, also run natively on Intel chips. Other applications (including Microsoft Office) which have not been updated to run on the Intel architecture, run using a technology known as Rosetta. Because Rosetta is a translation software that allows PowerPC programs to run on Intel processors, these PowerPC programs run slower than native applications. Programs compiled only for the PowerPC must be recompiled to run at full speed on the new Intel machines. Programs that have been designed to run on both PowerPC and Intel chips can be certified by Apple as "Universal".^[39] The Intel-based machines also do not support Classic, which allows Mac OS X to run applications written for OS 9 and earlier, so applications that require this environment will not run on these machines. Apple currently has no plans to bring Classic support to the Intel platform.

The Intel chip also allows the new machines to run the Windows operating system. On March 16, 2006 a bootloader CD image and a how-to for getting XP on your MacBook Pro, iMac, or mini was released to the Internet as an entry into a US$13,000 contest. Many hackers attempted over three months to win the prize by becoming the first to run Windows natively on a new Intel Mac. The Intel-based Macs are now the only computers officially capable of running both Mac OS X and Windows without emulation (a pre-release version of Mac OS X for Intel was patched to run on non-Apple PCs through the OSx86 community, however such procedure is not permitted by the Apple EULA). Further, on April 5, 2006, Apple announced a new piece of software called Boot Camp that helps users install Windows XP on their Intel Mac alongside Mac OS X. Apple has said that Boot Camp will be included, as standard, in Apple's next OS release (10.5, “Leopard”).

The first Intel-based Mac computer: The iMac

The Apple/Intel partnership coined several catch phrases among Apple fans and technology reporters. Some of the most widespread ones include "Mactel" and "Macintel", a response to the phrase "Wintel", which is an informal moniker that describes all Intel-powered systems running the Microsoft Windows operating system. Another is "ICBM", for "Intel-chip-based Mac." Apple itself has not publicly used these terms.

Apple's success during this period, beginning in 1997 (the first year the company turned a profit after losses through 1995 and 1996),^[40] but accelerating between 2003 to 2005, was evident in its skyrocketing stock. Between early 2003 and January 2006, the price of a share of Apple's stock increased more than tenfold, from a little more than US$6 per share (split-adjusted) to more than US$80 per share. On January 13, 2006, Apple's market cap surpassed that of Dell.^[41] Nearly ten years prior, in 1997, Dell's CEO, Michael Dell, had asserted that if he ran Apple he would "shut it down and give the money back to the shareholders."^[42]

Delivering his keynote at Macworld 2007 (January 9, 2007), Steve Jobs announced a change of name: Apple Computer Inc. would from that point be known as Apple Inc. The event also saw the announcement of the Apple iPhone, which will be available through AT&T Mobility at 6pm (local time) on June 29, 2007 and the Apple TV (which began shipping in March 2007). The following day, Apple shares hit US$97.80, then an all-time high. In May 2007, Apple's share price passed the US$100 mark.^[43]

On February 7, 2007, Apple indicated that it would be willing to sell music on the iTunes store without Digital Rights Management (DRM) protection (allowing tracks to be played on any compatible player) if major record labels would agree to drop that anti-piracy technology.^[44] On April 2, 2007, Apple and record label EMI jointly-announced the removal of anti-piracy technology from EMI's catalog in the iTunes Store, effective in May.^[45]

2007-06-22T09:04:00.001-07:00

Computer architecture

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A typical vision of a computer architecture as a series of abstraction layers: hardware, firmware, assembler, kernel, operating system and applications (see also Tanenbaum 79).

In computer engineering, computer architecture is the conceptual design and fundamental operational structure of a computer system. It is a blueprint and functional description of requirements (especially speeds and interconnections) and design implementations for the various parts of a computer — focusing largely on the way by which the central processing unit (CPU) performs internally and accesses addresses in memory.

It may also be defined as the science and art of selecting and interconnecting hardware components to create computers that meet functional, performance and cost goals.

Computer architecture comprises at least three main subcategories ^[1]

Instruction set architecture, or ISA, is the abstract image of a computing system that is seen by a machine language (or assembly language) programmer, including the instruction set, memory address modes, processor registers, and address and data formats.

Microarchitecture, also known as Computer organization is a lower level, more concrete, description of the system that involves how the constituent parts of the system are interconnected and how they interoperate in order to implement the ISA^[2]. The size of a computer's cache for instance, is an organizational issue that generally has nothing to do with the ISA.

System Design which includes all of the other hardware components within a computing system such as:

system interconnects such as computer buses and switches
memory controllers and hierarchies
CPU off-load mechanisms such as direct memory access
issues like multi-processing.

Once both ISA and microarchitecture has been specified, the actual device needs to be designed into hardware. This design process is often called implementation. Implementation is usually not considered architectural definition, but rather hardware design engineering.

Implementation can be further broken down into three pieces:

Logic Implementation/Design - where the blocks that were defined in the microarchitecture are implemented as logic equations.
Circuit Implementation/Design - where speed critical blocks or logic equations or logic gates are implemented at the transistor level.
Physical Implementation/Design - where the circuits are drawn out, the different circuit components are placed in a chip floor-plan or on a board and the wires connecting them are routed.

For CPUs, the entire implementation process is often called CPU design.

More specific usages of the term include more general wider-scale hardware architectures, such as cluster computing and Non-Uniform Memory Access (NUMA) architectures.

2007-06-22T08:43:00.000-07:00

Computer

A device that receives, processes, and presents information. The two basic types of computers are analog and digital. Although generally not regarded as such, the most prevalent computer is the simple mechanical analog computer, in which gears, levers, ratchets, and pawls perform mathematical operations—for example, the speedometer and the watt-hour meter (used to measure accumulated electrical usage). The general public has become much more aware of the digital computer with the rapid proliferation of the hand-held calculator and a large variety of intelligent devices and especially with exposure to the Internet and the World Wide Web. See also Calculators; Internet; World Wide Web.

An analog computer uses inputs that are proportional to the instantaneous value of variable quantities, combines these inputs in a predetermined way, and produces outputs that are a continuously varying function of the inputs and the processing. These outputs are then displayed or connected to another device to cause action, as in the case of a speed governor or other control device. Small electronic analog computers are frequently used as components in control systems. If the analog computer is built solely for one purpose, it is termed a special-purpose electronic analog computer. In any analog computer the key concepts involve special versus general-purpose computer designs, and the technology utilized to construct the computer itself, mechanical or electronic. See also Analog computer.

In contrast, a digital computer uses symbolic representations of its variables. The arithmetic unit is constructed to follow the rules of one (or more) number systems. Further, the digital computer uses individual discrete states to represent the digits of the number system chosen. A digital computer can easily store and manipulate numbers, letters, images, sounds, or graphical information represented by a symbolic code. Through the use of the stored program, the digital computer achieves a degree of flexibility unequaled by any other computing or data-processing device.

The advent of the relatively inexpensive and readily available personal computer, and the combination of the computer and communications, such as by the use of networks, have dramatically expanded computer applications. The most common application now is probably text and word processing, followed by electronic mail. See also Electronic mail; Local-area networks; Microcomputer; Word processing.

Computers have begun to meet the barrier imposed by the speed of light in achieving higher speeds. This has led to research and development in the areas of parallel computers (in order to accomplish more in parallel rather than by serial computation) and distributed computers (taking advantage of network connections to spread the work around, thus achieving more parallelism). Continuing demand for more processing power has led to significant changes in computer hardware and software architectures, both to increase the speed of basic operations and to reduce the overall processing time. See also Computer systems architecture; Concurrent processing; Distributed systems (computers); Multiprocessing; Supercomputer.