主要介绍 1950 年之后，计算机系统发展的变化，从大型机一路延展，有不同的发展方向
1964 年是一个重要的年份，着重介绍 System/360 和 PDP-8
高价 -> 低价（普及） -> 高价（时尚）
With technology, what you can do influences what you want to do—which gradually expands what you can do.
Businesses in the 1950s increasingly recognized computers’ broad potential. They demanded flexible, large-scale machines able to consolidate varied tasks. The workhorse mainframe computers that met these demands in turn reshaped how businesses operate, increasing centralization and nourishing new demand for powerful mainframes.
The First Mainframes
Big businesses with big needs required big computers. Economies of scale also favored large, consolidated computer systems.
This demand for big computers, just when “second generation” transistor-based computers were replacing vacuum-tube machines in the late 1950s, spurred developments in hardware and software. Manufacturers commonly built small numbers of each model, targeting narrowly defined markets.
Why are they called “Mainframes”?
Nobody knows for sure. There was no mainframe “inventor” who coined the term.
Probably “main frame” originally referred to the frames (designed for telephone switches) holding processor circuits and main memory, separate from racks or cabinets holding other components. Over time, main frame became mainframe and came to mean “big computer.”
IBM dominated computing in 1961, with about two-thirds of the American market. But could IBM hold onto its lead? Its product line was fragmented with incompatible machines, poorly suited to offer companies a single, unified, easily expandable system.
IBM’s System/360, a new family of general-purpose computers, changed everything. Programs for one System/360 computer ran on all, letting customers readily consolidate computing capabilities.
Every subsequent IBM mainframe is a descendant of the first System/360s.
The Five Billion Dollar Gamble
IBM’s revenue in 1962 was $2.5 billion. Developing System/360 cost twice that. Company president Tom Watson, Jr. had literally bet the company on it.
Watson unveiled System/360 in 1964 — six computers with a performance range of 50 to 1, and 44 new peripherals — with great fanfare. Orders flooded in. The gamble paid off.
Plays Well With Others
Compatibility was fundamental to System/360—and not just compatibility within IBM’s product line.
Clear, consistent, readily available specifications for System/360 components nourished a thriving market of third-party peripherals, making IBM computers even more practical and flexible. Varied “plug-compatible” devices easily substituted for IBM devices, often performing better at lower cost.
In 1960, IBM’s Gene Amdahl was named manager of architecture for their new System/360 family of mainframe computers. Amdahl’s challenge was to design a family of computers that would support a range of speeds and peripherals yet run the same software. The System/360, announced in April of 1964, became IBM’s most profitable product and Amdahl a legendary figure in the industry. Amdahl’s initial S/360 architecture influenced generations of later IBM mainframes, including some available today.
System/360’s software was also ambitious. Variations of one operating system, OS/360, were supposed to run on all the models.
But OS/360 was hard to write – especially the complex “multiprogramming” versions that ran several programs at once – and it was late. Three special OSs had to be created for the smallest machines.
Fred Brooks, IBM engineer
Brooks is legendary for having rescued IBM’s floundering software-development program for the first System/360 computers. When he stepped in, over 1,000 programmers were working on the operating system
In addition to the underlying principle of compatibility, System/360 incorporated many hardware advances, including options for very large main memories and Solid Logic Technology (hybrid integrated circuits).
It also used microprogramming, software that implemented some complicated instructions that would otherwise need special hardware – key to making the smaller models do everything.
In the early days of computing, most users developed software for their own computers, and it rarely ran on other models. Many manufacturers “bundled” programs with their computers—that software was free.
With software either custom made or given away free, there was a limited commercial market for it. At least, not until a lawsuit against IBM changed the game.
From Giving Software to Selling Software
IBM was in the hardware business. Marketing strategy focused on increasing sales volume, and on helping customers solve problems. Free software was a means to both ends: an incentive to buy IBM machines and a way to meet customer needs.
With a huge community of users willing to share programs, IBM amassed a vast, free software library. Rivals objected, sparking a Justice Department antitrust suit in the late 1960s.
In 1969, IBM unbundled many programs (separating software from hardware). Overnight, software changed from a giveaway to a competitive commercial product.
Sharing Software & Advice
As computing exploded in the 1950s, the advantages of cooperation often outweighed any benefits of competition. This was particularly true for software, not yet a commercial product.
In 1955, IBM users formed a group called SHARE. Members traded documentation and software not offered by IBM. A half century later, SHARE remains active.
Less is More: Smaller, Simpler, Cheaper
This new kind of computer, smaller and simpler than mainframes, was designed to interact directly with users and the outside world. A flexible, inexpensive tool, it brought computers within the reach of a larger and more diverse range of customers.
Minis also sparked a new generation of computer companies. Competition accelerated innovation and reduced prices, spurring broad adoption.
A New Approach to Computers
There were small computers as early as the 1950s. But they were expensive and slow—which meant you had to be important to have one…and not in a rush.
As the cost of transistors and memory dropped, however, fast, small computers became affordable. They began to appear in the lab, inside corporate departments, and on the manufacturing line.
The First PC?
Three years before DEC launched its wildly successful PDP-8 minicomputer, MIT physicist Wes Clark had already begun building an affordable, easy to use, “personal” computer.
Working with MIT neuroscientist Walter Rosenblith and physiologist Charles Molnar, Clark built a prototype computer that could be used in the laboratory to collect and process data from experiments.
At its 1962 meeting, the National Academy of Sciences was so impressed with Clark’s LINC (Laboratory Instrument Computer) that it funded the construction of about a dozen more for science laboratories around the country.
The Canadian Chalk River Nuclear Lab needed a special device to monitor a reactor. Instead of designing a custom controller, two young engineers from Digital Equipment Corporation (DEC) – Gordon Bell and Edson de Castro – do something unusual: they develop a small, general purpose computer and program it to do the job. A later version of that machine became the PDP-8, the first commercially successful minicomputer. The PDP-8 sold for $18,000, one-fifth the price of a small IBM System/360 mainframe. Because of its speed, small size, and reasonable cost, the PDP-8 was sold by the thousands to manufacturing plants, small businesses, and scientific laboratories around the world.
Over a 25 year span, DEC manufactured more than a dozen variations of the PDP-8 and sold over 10,000 machines.
The Canadian Chalk River Nuclear Lab approached Digital Equipment Corporation in 1964. It needed a special device to monitor a reactor.
Instead of designing a custom, hard-wired controller as expected, young DEC engineers C. Gordon Bell and Edson de Castro did something unusual: they developed a small, general purpose computer and programmed it to do the job.
A later version of that machine became the PDP-8, one of the most successful computers of the next decade.
Engineers used the inexpensive PDP-8 in many varied applications, such as the control of the news display in New York’s Times Square, inexpensive time sharing at Carnegie Mellon University, signal analysis in physics labs, and lighting control in New York’s Shubert Theater for the musical “A Chorus Line”.
Smaller Packaging: The Flip Chip Card
The PDP-8’s electronic components were mounted on small inexpensive “Flip Chip” modules about the size of playing cards, plugged into connectors on a panel. The wire interconnections on the back of the panel were automatically made by a machine that wrapped wires around metal pins sticking out of the connectors, which significantly reduced cost.
The Flip Chip cards, smaller than the cards in the predecessor PDP-5, were originally designed for unpackaged diodes and transistors densely mounted on ceramic substrates. That idea failed. But with clever layout, DEC engineers were able to squeeze conventionally packaged components into the new smaller size.
For the next compatible machine, the PDP-8I, the Flip Chip cards held integrated circuits instead, which packed much more logic into the same space.
Wang was a successful calculator manufacturer, then a successful word processor company. The 1973 Wang 2200 makes it a successful computer company, too. Wang sold the 2200 primarily through Value Added Resellers, who added special software to solve specific customer problems. The 2200 used a built-in CRT, cassette tape for storage, and ran the programming language BASIC. The PC era ended Wang’s success, and it filed for bankruptcy in 1992.
An Wang, born and educated in China, came to the U.S. after World War II and got his PhD from Harvard. There he invented a type of magnetic core logic circuits. Wang co-founded Wang Laboratories in 1951.
Wang Laboratories was a successful calculator company. Then a successful word processor company. The 1973 Wang 2200 made it a successful computer company too. Wang sold the 2200 primarily through Value Added Resellers, who added special software to solve customer problems.
The PC era ended Wang’s success. It filed for bankruptcy in 1992.
The Wang 2200 was unusual because it could only be programmed in the BASIC language—the “machine language” was hidden from users. The computer was targeted primarily at business customers.
Computers evolved primarily for military, scientific, government, and corporate users with substantial needs…and substantial budgets. They populated labs, universities, and big companies. Homes? Small businesses? Not so much.
Over time, however, costs dropped. Equally important, computers grew sophisticated enough to hide their complex, technical aspects behind a user-friendly interface. Individuals could now afford and understand computers, which dramatically changed everyday life.
Designed by Sunnyvale, California native Steve Wozniak, and marketed by his friend Steve Jobs, the Apple-1 is a single-board computer for hobbyists. With an order for 50 assembled systems from Mountain View, California computer store The Byte Shop in hand, the pair started a new company, naming it Apple Computer, Inc. In all, about 200 of the boards were sold before Apple announced the follow-on Apple II a year later as a ready-to-use computer for consumers, a model which sold in the millions for nearly two decades.
Steve Wozniak debuted the prototype Apple-1 at the Homebrew Computer Club in 1976. For $666.66, buyers received a simple single-board computer with 4K of RAM. A cassette-based BASIC programming language simplified interaction though users had to add a power supply, keyboard, storage system, and display to build a fully-functioning system.
When Steve Jobs and Steve Wozniak completed the Apple I, they didn’t alert the media. They demonstrated it to their soul mates at the Homebrew Computer Club.
The Homebrew Club—like similar clubs—was a forum for sharing ideas. It attracted hobbyists and those eager to experiment, many of whom became leaders in personal computing.
Computer in a Box: The Altair 8800
Even do-it-yourselfers didn’t do it entirely themselves. The Altair 8800 was the first popular computer kit.
The Altair’s appearance on the January 1975 cover of Popular Electronics excited hobbyists. An avalanche of orders followed. It also excited two young programmers who provided a BASIC language interpreter: Paul Allen and Bill Gates.
The Computer Museum in Boston asked that question in 1986, and held a contest to find the answer. Judges settled on John Blankenbaker’s Kenbak-1 as the first personal computer.
Designed in 1971, before microprocessors were invented, the Kenbak-1 had 256 bytes of memory and featured small and medium scale integrated circuits on a single circuit board.
The title of first personal computer using a microprocessor went to the 1973 Micral. Designed in France by André Truong Trong Thi and Francois Gernelle, the Micral used the Intel 8008 microprocessor.
John Blankenbaker’s Kenbak-1, winner of The Computer Museum’s “Earliest PC Contest,” used small- and medium-scale integrated circuits, had switches and lights for input/output, and came with 256 bytes of memory. Kenbak Corporation folded in 1973 after selling only 40 computers.
Sold complete with a main logic board, switching power supply, keyboard, case, manual, game paddles, and cassette tape containing the game Breakout, the Apple-II finds popularity far beyond the hobbyist community which made up Apple’s user community until then. When connected to a color television set, the Apple II produced brilliant color graphics for the time. Millions of Apple IIs were sold between 1977 and 1993, making it one of the longest-lived lines of personal computers. Apple gave away thousands of Apple IIs to school, giving a new generation their first access to personal computers.
Steve Wozniak designed the Apple II in 1977. The self-contained unit housed electronics, keyboard and power supply, with the BASIC language in permanent memory. A TV served as the display. The floppy disk drive (1978) and spreadsheet program VisiCalc (1979) made it a blockbuster.
A Tale of Two Steves
Steve Wozniak and Steve Jobs founded Apple Computer in 1976. Corporate headquarters? The Jobs family garage.
Wozniak and Jobs met in 1971, creating and selling “Blue Boxes,” devices for making free long-distance calls. After stints at Hewlett Packard and Atari respectively, they reunited, formed Apple, and demonstrated the Apple I to the savvy hobbyists at the Homebrew Computer Club.
It was their more fully developed Apple II, however, that established Apple. They built the company with Jobs focusing on promotion and creating a distinct Apple identity, and Wozniak as the designer.
IBM’s brand recognition, along with a massive marketing campaign, ignites the fast growth of the personal computer market with the announcement of its own personal computer (PC). The first IBM PC, formally known as the IBM Model 5150, was based on a 4.77 MHz Intel 8088 microprocessor and used Microsoft´s MS-DOS operating system. The IBM PC revolutionized business computing by becoming the first PC to gain widespread adoption by industry. The IBM PC was widely copied (“cloned”) and led to the creation of a vast “ecosystem” of software, peripherals, and other commodities for use with the platform.
IBM’s first personal computer arrived nearly 10 years after others were available, but instantly legitimized the market. Unlike most previous IBM products, the PC incorporated hardware and software from other companies. IBM published design details, inspiring often superior “clones.”
Many companies were dubious. Could small personal computers really be serious business tools? The IBM name was a reassuring seal of approval.
IBM introduced its PC in 1981 with a folksy advertising campaign aimed at the general public. Yet, the IBM PC had its most profound impact in the corporate world. Companies bought PCs in bulk, revolutionizing the role of computers in the office—and introducing the Microsoft Disk Operating System (MS DOS) to a vast user community.
IBM Rules the Office
As the leading business computer manufacturer, IBM had a large, loyal customer base. It also had credibility, which reassured companies that personal computers weren’t just playthings, but made good business sense.
Businesses bought IBM PCs in quantity. Personal computers and workstations ultimately reached desks at every corporate level.
Growing sales nourished a rapidly expanding software market for the PC platform—including spreadsheet and word processing software that became integral parts of corporate life. This expanding library of programs made IBM PCs an ever more versatile tool, which further generated sales.
Apple introduces the Macintosh with a television commercial during the 1984 Super Bowl, which plays on the theme of totalitarianism in George Orwell´s book 1984. The ad featured the destruction of “Big Brother” – a veiled reference to IBM – through the power of personal computing found in a Macintosh. The Macintosh was the first successful mouse-driven computer with a graphical user interface and was based on the Motorola 68000 microprocessor. Its price was $2,500. Applications that came as part of the package included MacPaint, which made use of the mouse, and MacWrite, which demonstrated WYSIWYG (What You See Is What You Get) word processing.
The first IBM system to include Intel´s 80386 chip, the company ships more than 1 million units by the end of the first year. IBM released a new operating system, OS/2, at the same time, allowing the use of a mouse with IBM PCs for the first time. Many credit the PS/2 for making the 3.5-inch floppy disk drive and video graphics array (VGA) standard for IBM computers. The system was IBM’s response to losing control of the PC market with the rise of widespread copying of the original IBM PC design by “clone” makers.
Early computers were so heavy that the floor below sometimes needed reinforcing. Today, computers slip into purses or pockets and are misplaced as easily as keys.
Miniaturization and falling costs made it possible to take computers everywhere, and to merge them with devices like phones and cameras. Wireless communication over global networks weaves computing into our lives wherever we go.
Portability isn’t a modern concept. It’s a return to our roots.
Our nomadic ancestors designed transportable tools. Over time common sizes and shapes emerged, based on how we held and used them. The smallest, like wristwatches, were worn. Small knives could be pocketed. Saws were carried. Cannons were transported as vehicles.
Many early mechanical calculating tools were portable, including slide rules, sextants, and calculators.
Computers have appeared in all these formats. The most successful so far have been carried or handheld, not vehicle-based or worn.
Apple enters the handheld computer market with the Newton. Dubbed a “Personal Data Assistant” by Apple President John Scully in 1992, the Newton featured many of the features that would define handheld computers in the following decades. The handwriting recognition software was much maligned for inaccuracy. The Newton line never performed as well as hoped and was discontinued in 1998.
Officially known as the Track Write, the automatically expanding full-sized keyboard used by the ThinkPad 701 is designed by inventor John Karidis. The keyboard was comprised of three roughly triangular interlocking pieces, which formed a full-sized keyboard when the laptop was opened – resulting in a keyboard significantly wider than the case. This keyboard design was dubbed “the Butterfly.” The need for such a design was lessened as laptop screens grew wider.
Sony had manufactured and sold computers in Japan, but the VAIO signals their entry into the global computer market. The first VAIO, a desktop computer, featured an additional 3D interface on top of the Windows 95 operating system as a way of attracting new users. The VAIO line of computers would be best known for laptops were designed with communications and audio-video capabilities at the forefront, including innovative designs that incorporated TV and radio tuners, web cameras, and handwriting recognition. The line was discontinued in 2014.
Japan’s SoftBank introduces the first camera phone, the J-Phone J-SH04; a Sharp-manufactured digital phone with integrated camera. The camera had a maximum resolution of 0.11 megapixels a 256-color display, and photos could be shared wirelessly. The J-Phone line would quickly expand, releasing a flip-phone version just a month later. Cameras would become a significant part of most phones within a year, and several countries have even passed laws regulating their use.
Harkening back to the hobbyist era of personal computing in the 1970s, Arduino begins as a project of the Interaction Design Institute, Ivrea, Italy. Each credit card-sized Arduino board consisted of an inexpensive microcontroller and signal connectors which made Arduinos ideal for use in any application connecting to or monitoring the outside world. The Arduino used a Java-based integrated development environment and users could access a library of programs, called “Wiring,” that allowed for simplified programming. Arduino soon became the main computer platform of the worldwide “Maker” movement.
Many companies have attempted to release electronic reading systems dating back to the early 1990s. Online retailer Amazon released the Kindle, one of the first to gain a large following among consumers. The first Kindle featured wireless access to content via Amazon.com, along with an SD card slot allowing increased storage. The first release proved so popular there was a long delay in delivering systems on release. Follow-on versions of the Kindle added further audio-video capabilities.
Apple launches the iPhone - a combination of web browser, music player and cell phone - which could download new functionality in the form of “apps” (applications) from the online Apple store. The touchscreen enabled smartphone also had built-in GPS navigation, high-definition camera, texting, calendar, voice dictation, and weather reports.
Apple introduces their first ultra notebook – a light, thin laptop with high-capacity battery. The Air incorporated many of the technologies that had been associated with Apple’s MacBook line of laptops, including integrated camera, and Wi-Fi capabilities. To reduce its size, the traditional hard drive was replaced with a solid-state disk, the first mass-market computer to do so.
The iPad combines many of the popular capabilities of the iPhone, such as built-in high-definition camera, access to the iTunes Store, and audio-video capabilities, but with a nine-inch screen and without the phone. Apps, games, and accessories helped spur the popularity of the iPad and led to its adoption in thousands of different applications from movie making, creating art, making music, inventory control and point-of-sale systems, to name but a few.
The Nest Learning Thermostat is an early product made for the emerging “Internet of Things,” which envisages a world in which common everyday devices have network connectivity and can exchange information or be controlled. The Nest allowed for remote access to a user’s home’s thermostat by using a smartphone or tablet and could also send monthly power consumption reports to help save on energy bills. The Nest would remember what temperature users preferred by ‘training’ itself to monitor daily use patterns for a few days then adopting that pattern as its new way of controlling home temperature.
Raspberry Pi, a credit-card-size single board computer, is released as a tool to promote science education 2012
Conceived in the UK by the Raspberry Pi Foundation, this credit card-sized computer features ease of use and simplicity making it highly popular with students and hobbyists. In October 2013, the one millionth Raspberry Pi was shipped. Only one month later, another one million Raspberry Pis were delivered. The Pi weighed only 45 grams and initially sold for only $25-$35 U.S. Dollars.
Building a computer into the watch form factor has been attempted many times but the release of the Apple Watch leads to a new level of excitement. Incorporating a version of Apple’s iOS operating system, as well as sensors for environmental and health monitoring, the Apple Watch was designed to be incorporated into the Apple environment with compatibility with iPhones and Mac Books. Almost a million units were ordered on the day of release. The Watch was received with great enthusiasm, but critics took issue with the somewhat limited battery life and high price.
Keyboard pointing stick
Laptops and non-pen handhelds share a challenge: how to reproduce the pointing functions of a mouse in a small space? IBM’s “pointing stick” for laptop keyboards was one elegant solution.
Portable computers with screens and keyboards similar to those of their desktop cousins could use similar interfaces. The mouse might become a trackpad, but the difference was subtle.
For handhelds, engineers had to rethink user interfaces from scratch. The small screens and the tiny or non-existent keyboards demanded new approaches.
Apple’s iPhone introduced a touch interface operated by fingers, not a pen. It included gestures like multi-finger zoom and scrolling by “flicking.” The virtual keyboard, with its lack of tactile feedback, took getting used to.
Most early handhelds sported tiny keys that reduced even touch typists to hunt-and-peck. In the mid 1990s, effective handwriting recognition—and the two-thumb keyboards popularized by RIM—offered relief.