The Computer History Museum

A Cray-2 supercomputer at the Computer History Museum

An example of Google's custom server racks on display

The Computer History Museum is a museum established in 1996 in Mountain View, California, USA. The Museum is dedicated to preserving and presenting the stories and artifacts of the information age, and exploring the computing revolution and its impact on our lives.

History[link]

The museum's origins date to 1968 when Gordon Bell began a quest for a historical collection and, at that same time, others were looking to preserve the Whirlwind computer. The resulting Museum Project had its first exhibit in 1975; located in a converted coat closet in a DEC lobby. In 1978, the museum, now The Digital Computer Museum (TDCM), moved to a larger DEC lobby in Marlboro, Mass. Maurice Wilkes presented the first lecture at TDCM in 1979 – the presentation of such lectures has continued to the present time.

TDCM incorporated as The Computer Museum (TCM) in 1982. In 1984, TCM moved to Boston, locating on Museum Wharf.

In 1996/1997, The TCM History Center (TCMHC) in Silicon Valley was established; a site at Moffet Field was provided by NASA (an old building that was previously the Naval Base furniture store) and a large number of artifacts were shipped there from TCM.

In 1999, TCMHC incorporated and TCM ceased operation, shipping its remaining artifacts to TCMHC in 2000. The name TCM had been retained by the Boston Museum of Science so, in 2000, the name TCMHC was changed to Computer History Museum (CHM).

In 2003, CHM opened its new building (previously occupied by Silicon Graphics), at 1401 N. Shoreline Blvd in Mountain View, California, to the public.^[1][2]

Current[link]

The Computer History Museum claims to house the largest and most significant collection of computing artifacts in the world (the Heinz Nixdorf Museum, Paderborn, Germany, has more items on display but a far smaller total collection^[3]). This includes many rare or one-of-a-kind objects such as a Cray-1 supercomputer as well as a Cray-2, Cray-3, the Utah teapot, the 1969 Neiman Marcus Kitchen Computer, an Apple I, and an example of the first generation of Google's racks of custom-designed web servers.^[4] The collection comprises nearly 90,000 objects, photographs and films, as well as 4,000 feet (1,200 m) of cataloged documentation and several hundred gigabytes of software.

The museum's 25,000-square-foot (2,300 m²) exhibition "Revolution: The First 2000 Years of Computing," opened to the public on January 13, 2011. It covers the history of computing in 20 galleries, from the abacus to the Internet. The entire exhibition is also available online. ^[5][6][7]

The museum has two additional exhibits highlighting important milestones from the history of computing: "Mastering the Game," a history of computer chess and a Difference Engine designed by Charles Babbage in the 1840s and constructed by the Science Museum.

Former media executive John Hollar was appointed CEO of The Computer History Museum in July 2008.

See also[link]

• Vintage Computer Festival held annually at The Computer History Museum
• Computer museums
• History of computing
• History of computer science

Notes and references[link]

Further reading[link]

• Bell, Gordon (2011). Out of a Closet: The Early Years of the Computer [x]* Museum. Microsoft Technical Report MSR-TR-2011-44.

External links[link]

	San Francisco Bay Area portal
	Computing portal

Wikimedia Commons has media related to: Computer History Museum

• Computer History Museum website.
• Computer History Museum videos.
• Catalog Search - Search for the museum collections
• WAVE report on the Computer History Museum, with many photographs of interesting artifacts. Note: many links on this site do fail because their letter case does not match that of the destination file. Try altering the URL to access the file's directory instead.

Other photographs from the Computer History Museum[link]

• 

  Cray-1 near the Visible Storage room

• 

  Cray-1A power supply

• Computerhistorymuseum 1647.JPG

  Visible Storage

• ShakeyLivesHere.jpg

  Shakey

• 

  Difference Engine

• 

  Galaxy Game

Coordinates: 37°24′52″N 122°04′37″W / 37.414371°N 122.076817°W / 37.414371; -122.076817

The Louvre Museum in Paris, one of the largest and most famous museums in the world.

The Hermitage Museum in St. Petersburg

The British Museum in London

The Uffizi Gallery, the most visited museum in Italy and one of most important in the world. View toward the Palazzo Vecchio, in Florence.

A museum is an institution that cares for a collection of artifacts and other objects of scientific, artistic, cultural, or historical importance and makes them available for public viewing through exhibits that may be permanent or temporary.^[1] Most large museums are located in major cities throughout the world and more local ones exist in smaller cities, towns and even the countryside. The continuing acceleration in the digitization of information, combined with the increasing capacity of digital information storage, is causing the traditional model of museums (i.e. as static “collections of collections” of three-dimensional specimens and artifacts) to expand to include virtual exhibits and high-resolution images of their collections for perusal, study, and exploration from any place with Internet connectivity.

Etymology[link]

The English "museum" comes from the Latin word, and is pluralized as "museums" (or rarely, "musea"). It is originally from the Greek Μουσεῖον (Mouseion), which denotes a place or temple dedicated to the Muses (the patron divinities in Greek mythology of the arts), and hence a building set apart for study and the arts,^[2] especially the Musaeum (institute) for philosophy and research at Alexandria by Ptolemy I Soter about 280 BCE.^[3] The first museum/library is considered to be the one of Plato in Athens.^[4] However, Pausanias gives another place called "Museum", namely a small hill in Classical Athens opposite the Akropolis. The hill was called Mouseion after Mousaious, a man who used to sing on the hill and died there of old age and was subsequently buried there as well.^[5]

Purpose[link]

Hampton Court Palace, the great gatehouse.

Museum purposes change from institution to institution. Some favor education over conservation, or vice versa. For example, in the 1970s, the Canada Science and Technology Museum favored education over preservation of their objects. They displayed objects as well as their functions. One exhibit featured a historic printing press that a staff member used for visitors to create museum memorabilia.^[6] Some seek to reach a wide audience, such as a national or state museum, while some museums have specific audiences, like the LDS Church History Museum or local history organizations. Generally speaking, museums collect objects of significance that comply with their mission statement for conservation and display. Although most museums do not allow physical contact with the associated artifacts, there are some that are interactive and encourage a more hands-on approach. In 2009, Hampton Court Palace, palace of Henry VIII, opened the council room to the general public to create an interactive environment for visitors. Rather than allowing visitors to handle 500 year old objects, the museum created replicas, as well as replica costumes. The daily activities, historic clothing, and even temperature changes immerse the visitor in a slice of what Tudor life may have been.^[7]

History[link]

The museums of ancient times, such as the Musaeum of Alexandria, would be equivalent to a modern graduate institute.

The State Historical Museum in Moscow

Museo Nacional de Antropología in Mexico City

Early museums began as the private collections of wealthy individuals, families or institutions of art and rare or curious natural objects and artifacts. These were often displayed in so-called wonder rooms or cabinets of curiosities. Public access was often possible for the "respectable", especially to private art collections, but at the whim of the owner and his staff. The oldest such museum in evidence was Ennigaldi-Nanna's museum, dating from c. 530 BC and devoted to Mesopotamian antiquities; it apparently had sufficient traffic as to warrant labels for the ordered collection.

The oldest public museums in the world opened in Rome during the Renaissance. However, many significant museums in the world were not founded until the 18th century and the Age of Enlightenment:

• the Capitoline Museums, the oldest public collection of art in the world, began in 1471 when Pope Sixtus IV donated a group of important ancient sculptures to the people of Rome.
• the Vatican Museums, the second oldest museum in the world, traces its origins to the public displayed sculptural collection begun in 1506 by Pope Julius II
• the Amerbach Cabinet, originally a private collection, was bought by the university and city of Basel in 1661 and opened to the public in 1671.
• the Royal Armouries in the Tower of London is the oldest museum in the United Kingdom. It opened to the public in 1660, though there had been paying privileged visitors to the armouries displays from 1592. Today the museum has three sites including its new headquarters in Leeds.^[8]
• the Musée des Beaux-Arts et d'archéologie in Besançon was established in 1694 after Jean-Baptiste Boisot, an abbot, gave his personal collection to the Benedictines of the city in order to create a museum open to the public two days every week.^[9]
• the Kunstkamera in St. Petersburg was founded in 1717 in Kikin Hall and officially opened to the public in 1727 in the Old St. Petersburg Academy of Science Building
• the British Museum in London, was founded in 1753 and opened to the public in 1759.^[10] Sir Hans Sloane's personal collection of curios provided the initial foundation for the British Museum's collection.^[10]
• the Uffizi Gallery in Florence, which had been open to visitors on request since the 16th century, was officially opened to the public 1765^{[citation needed]}
• the Hermitage Museum was founded in 1764 by Catherine the Great and has been open to the public since 1852.
• the Belvedere Palace of the Habsburg monarchs in Vienna opened with a collection of art in 1781^{[citation needed]}
• Louvre in Paris France. The Mona Lisa Painting by Leonardo Da Vinci resides in the Louvre.

The Orthodox Church, later an Ottoman mosque, and now a museum, Hagia Sophia was once the pride of the Byzantine Empire. Historically located in Constantinople, is now modern day Istanbul, Turkey

• The Charleston Museum was established in 1773 thereby making it the first American museum. It did not open to the public until 1824.^[11]

These "public" museums, however, were often accessible only by the middle and upper classes. It could be difficult to gain entrance. In London for example, prospective visitors to the British Museum had to apply in writing for admission. Even by 1800 it was possible to have to wait two weeks for an admission ticket.^{[citation needed]} Visitors in small groups were limited to stays of two hours.^{[citation needed]} In Victorian times in England it became popular for museums to be open on a Sunday afternoon (the only such facility allowed to do so) to enable the opportunity for "self improvement" of the other - working - classes.^{[citation needed]} The Ashmolean museum, however, founded in 1677 from the personal collection of Elias Ashmole, was set up in the University of Oxford to be open to the public and is considered by some to be the first modern public museum.^[12]

In France, the first public museum was the Louvre Museum in Paris,^{[citation needed]} opened in 1793 during the French Revolution, which enabled for the first time free access to the former French royal collections for people of all stations and status. The fabulous art treasures collected by the French monarchy over centuries were accessible to the public three days each "décade" (the 10-day unit which had replaced the week in the French Republican Calendar). The Conservatoire du muséum national des Arts (National Museum of Arts's Conservatory) was charged with organizing the Louvre as a national public museum and the centerpiece of a planned national museum system. As Napoléon I conquered the great cities of Europe, confiscating art objects as he went, the collections grew and the organizational task became more and more complicated. After Napoleon was defeated in 1815, many of the treasures he had amassed were gradually returned to their owners (and many were not). His plan was never fully realized, but his concept of a museum as an agent of nationalistic fervor had a profound influence throughout Europe.

American museums eventually joined European museums as the world's leading centers for the production of new knowledge in their fields of interest. A period of intense museum building, in both an intellectual and physical sense was realized in the late 19th and early 20th centuries (this is often called "The Museum Period" or "The Museum Age"). While many American museums, both Natural History museums and Art museums alike, were founded with the intention of focusing on the scientific discoveries and artistic developments in North America, many moved to emulate their European counterparts in certain ways (including the development of Classical collections from ancient Egypt, Greece, Mesopotamia and Rome). Drawing on Michel Foucault’s concept of liberal government, Tony Bennett has suggested the development of more modern 19th century museums was part of new strategies by Western governments to produce a “citizenry” that, rather than be directed by coercive or external forces, monitored and regulated its own conduct. To incorporate the masses in this strategy, the private space of “museums” that previously had been restricted and socially exclusive were made “public.” As such, objects and artifacts, particularly those related to high culture, became instruments for these “new tasks of social management.”^[13] Universities became the primary centers for innovative research in the United States well before the start of the Second World War. Nevertheless, museums to this day contribute new knowledge to their fields and continue to build collections that are useful for both research and display.

Management[link]

Vatican Museums

The roles associated with the management a museum largely depends on the size of the institution, but every museum has a hierarchy of governance with a Board of Trustees serving at the top. The Director is next in command and works with the Board to establish and fulfill the museum’s mission statement and to ensure that the museum is accountable to the public.^[14] Together, the Board and the Director establish a good system of governance that is guided by various other documents such as an institutional or strategic plan, institutional code of ethics, bylaws, and collections policy. The American Association of Museums (AAM) has also formulated a series of standards and best practices that help guide the management of museums. Unfortunately, many small, local museums lack this guidance since accreditation with AAM requires a museum to operate on an annual budget of at least $25,000.^[15]

A change in leadership may ultimately effect changes at the museum, as new directors commonly have new ideas for the institution they work for. For instance, the Los Angeles County Museum of Art’s Director and CEO, Michael Govan, has made great strides for the museum since he started in 2006. Undertaking elaborate building projects, acquiring large collections of objects, and creating new relationships with contemporary artists are just some of his accomplishments. While change and growth is often good for a museum, they should not reach outside the original mission statement of the institution.

Miami Art Museum in Miami, Florida

According to museum professionals Hugh H. Genoways and Lynne M. Ireland, “Administration of the organization requires skill in conflict management, interpersonal relations, budget management and monitoring, and staff supervision and evaluation. Managers must also set legal and ethical standards and maintain involvement in the museum profession.”^[16]

Various positions within the museum carry out the policies established by the Board and the Director. These positions include but are not limited to curators, collections managers/registrars, public programmers/educators, exhibition designers, and building operators. These positions and all other employees should work together toward the museum’s institutional goal.

• Curator – research the collection and most often write the text labels for exhibitions. In larger institutions, there may be a curator assigned to each collection of objects the museum holds. Ex: Curator of Modern Art, Curator of Natural History, Curator of History, etc.

• Collections Management/Registrar – responsible for the care and maintenance of all objects in the museum’s collection, tracks movement of objects in and out of the museum on loan or on exhibition, records information about objects in databases-such as an object's provenance. Registrars oversee the accessioning process, which formally accepts objects into the museum's collection with an accession number and detailed record. Collections Managers and Registrars uphold the Collections Policy, which guides what is and is not accepted into the museum collection.

• Public Programmer/Educator – creates programs for the public and designs interactives for exhibitions. This position also oversees volunteers and docents at the museum. Depending on the institution, educators may also research the collections and write text for exhibitions. Educators work with the Board, Director, and Curator to ensure that the needs of the public are met as laid out in the institution’s mission statement.

• Exhibition Designer – designs and installs the exhibition under the supervision of the curator and collections manager. They have the vital role of creating exhibition space that is navigable by the visitor.

• Building Operators – oversee security and maintenance of the museum. In larger museums, building operators will work with Collections Managers to maintain appropriate levels of temperature and humidity which can affect the stability of the objects.^[17]

Museum planning[link]

São Paulo Museum of Art in São Paulo, Brazil.

The design of museums has evolved throughout history. Interpretive museums, as opposed to art museums, have missions reflecting curatorial guidance through the subject matter which now include content in the form of images, audio and visual effects, and interactive exhibits. Museum creation begins with a museum plan, created through a museum planning process. The process involves identifying the museum's vision and the resources, organization and experiences needed to realize this vision. A feasibility study, analysis of comparable facilities and an interpretive plan are all developed as part of the museum planning process.

Some museum experiences have very few or no artifacts and do not necessarily call themselves museums; the Griffith Observatory in Los Angeles and the National Constitution Center in Philadelphia, being notable examples where there are few artifacts, but strong, memorable stories are told or information is interpreted. In contrast, the United States Holocaust Memorial Museum in Washington, D.C. uses many artifacts in their memorable exhibitions. Notably, despite their varying styles, the latter two were designed by Ralph Appelbaum Associates.

Exhibition design[link]

Most mid-size and large museums employ exhibit design staff for graphic and environmental design projects, including exhibitions. In addition to traditional 2-D and 3-D designers and architects, these staff departments may include audio-visual specialists, software designers, audience research and evaluation specialists, writers, editors, and preparators or art handlers. These staff specialists may also be charged with supervising contract design or production services. The exhibit design process builds on the interpretive plan for an exhibit, determining the most effective, engaging and appropriate methods of communicating a message or telling a story. The process will often mirror the architectural process or schedule, moving from conceptual plan, through schematic design, design development, contract document, fabrication and installation. Museums of all sizes may also contract the outside services of exhibit fabrication businesses. Predator Exhibits, located in Ontario, Canada, is one such business.

Exhibition design has as multitude of strategies, theories, and methods but two that embody much of the theory and dialogue surrounding exhibition design are the metonymy technique and the use of authentic artifacts to provide the historical narrative. Metonymy, or "the substitution of the name of an attribute or adjunct for that of the thing meant,"^[18] is a technique used by many museums but few as heavily and as influentially as Holocaust museums. The United States Holocaust Memorial Museum in Washington D.C., for example, employs this technique in its shoe exhibition. Simply a pile of decaying leather shoes piled against a bare, gray concrete wall the exhibit relies heavily on the emotional, sensory response the viewer will naturally through this use metonymic technique. This exhibition design intentionally signifies metonymically the nameless and victims themselves. This metaphysical link to the victims through the deteriorating and aged shoes stands as a the surviving vestige of the individual victim. This technique, employed properly, can be a very powerful one as it plays off the real life experiences of the viewer while evoking the equally unique memory of the victim. Metonymy, however, Jennifer Hansen-Glucklich argues, is not without its own problems. Hansen-Glucklich explains, ". . .when victims’ possessions are collected according to type and displayed en masse they stand metonymically for the victims themselves . . . Such a use of metonymy contributes to the dehumanization of the victims as they are reduced to a heap of indistinguishable objects and their individuality subsumed by an aesthetic of anonymity and excess."^[19] While a powerful technique Hansen-Glucklick points out that when used en masse the metonym suffers as the memory and suffering of the individual is lost in the chorus of the whole. While at times juxtaposed, the alternative technique of the use of authentic objects is seen the same exhibit mentioned above. The use of authentic artifacts is employed by most, if not all, museums but the degree to which and the intention can vary greatly. The basic idea behind exhibiting authentic artifacts is to provide not only legitimacy to the exhibit's historical narrative but, at times, to help create the narrative as well. The theory behind this technique is to exhibit artifacts in a neutral manner to orchestrate and narrate the historic narrative through, ideally, the provenance of the artifacts themselves. While albeit necessary to most some degree in any museum repertoire, the use of authentic artifacts can not only be misleading but as equally problematic as the aforementioned metonymic technique. Hansen-Glucklick explains, "The danger of such a strategy lies in the fact that by claiming to offer the remnants of the past to the spectator, the museum creates the illusion of standing before a complete picture. The suggestion is that if enough details and fragments are collected and displayed, a coherent and total truth concerning the past will emerge, visible and comprehensible. The museum attempts, in other words, to archive the unachievable."^[19] While any exhibit benefits from the legitimacy given by authentic objects or artifacts the temptation must be protected against in order to avoid relying solely on the artifacts themselves. A well designed exhibition should employ objects and artifacts as a foundation to the narrative but not as a crutch; a lesson any conscientious curator would be well to keep in mind.

Types[link]

The Martin Gusinde Anthropological Museum, located in the Navarino Island, is the southernmost museum in the world and preserves artefacts of the Yaghan people.

Types of museums vary, from large institutions, covering many of the categories below, to very small institutions focusing on a specific subject, location, or a notable person. Categories include: fine arts, applied arts, craft, archaeology, anthropology and ethnology, history, cultural history, science, technology, children's museums, natural history, botanical and zoological gardens. Within these categories many museums specialize further, e.g. museums of modern art, folk art, local history, military history, aviation history, philately, agriculture or geology. Another type of museum is an encyclopedic museum. Commonly referred to as a universal museum, encyclopedic museums have collections representative of the world and typically include art, science, history, and cultural history. The type and size of a museum is reflected in its collection. A museum normally houses a core collection of important selected objects in its field.

Gold Museum, Bogotá Colombia.

Archaeology museums[link]

Archaeology museums specialize in the display of archaeological artifacts. Many are in the open air, such as the Agora of Athens and the Roman Forum. Others display artifacts found in archaeological sites inside buildings. Some, such as the Western Australian Museum, exhibit maritime archaeological materials. These appear in its Shipwreck Galleries, a wing of the Maritime Museum. This Museum has also developed a 'museum-without-walls' through a series of underwater wreck trails.

Art museums[link]

Museum of Modern Art

An art museum, also known as an art gallery, is a space for the exhibition of art, usually in the form of art objects from the visual arts, primarily paintings, illustrations, and sculpture. Collections of drawings and old master prints are often not displayed on the walls, but kept in a print room. There may be collections of applied art, including ceramics, metalwork, furniture, artist's books and other types of object. Video art is often screened.

The first publicly owned museum in Europe was the Amerbach-Cabinet in Basel, originally a private collection sold to the city in 1661 and public since 1671 (now Kunstmuseum Basel).^[20] The Ashmolean Museum in Oxford opened on 24 May 1683 as the world's first university art museum. Its first building was built in 1678–1683 to house the cabinet of curiosities Elias Ashmole gave Oxford University in 1677. The Uffizi Gallery in Florence was initially conceived as a palace for the offices of Florentian magistrates (hence the name), it later evolved into a display place for many of the paintings and sculpture collected by the Medici family or commissioned by them. After the house of Medici was extinguished, the art treasures remained in Florence, forming one of the first modern museums. The gallery had been open to visitors by request since the sixteenth century, and in 1765 it was officially opened to the public. Another early public museum was the British Museum in London, which opened to the public in 1759.^[10] It was a "universal museum" with very varied collections covering art, applied art, archaeology, anthropology, history, and science, and a library. The science collections, library, paintings and modern sculpture have since been found separate homes, leaving history, archaeology, non-European and pre-Renaissance art, and prints and drawings.^{[citation needed]}

The specialised art museum is considered a fairly modern invention, the first being the Hermitage in Saint Petersburg which was established in 1764.^{[citation needed]}

The Louvre in Paris was established in 1793, soon after the French Revolution when the royal treasures were declared for the people.^[21] The Czartoryski Museum in Kraków was established in 1796 by Princess Izabela Czartoryska.^[22] This showed the beginnings of removing art collections from the private domain of aristocracy and the wealthy into the public sphere, where they were seen as sites for educating the masses in taste and cultural refinement.

Encyclopedic museums[link]

Encyclopedic museums are large, mostly national, institutions that offer visitors a plethora of information on a variety of subjects that tell both local and global stories. "With 3% of the world's population, or nearly 200 million people, live outside the country of their birth, encyclopedic museums play an especially important role in the building of civil society. They encourage curiosity about the world."^[23] James Cuno, President and CEO of the J. Paul Getty Trust, along with Neil MacGregor, Director of the British Museum, are two of the most outspoken museum professionals who support encyclopedic museums. Encyclopedic museums have advantages; however, some scholars and archaeologists argue against encyclopedic museums because they remove cultural objects from their original cultural setting, losing their context.^[24]

Historic house museums[link]

Within the category of history museums historic house museums are the most numerous. The earliest projects for preserving historic homes began in the 1850s under the direction of individuals concerned with the public good and the preservation of American history, especially centered on the first president. Since the establishment of America’s first historic site at Washington’s Revolutionary headquarters at Hasbrouck House in New York State, Americans have found a penchant for preserving similar historical structures. The establishment of historic house museums increased in popularity through the 1970s and 1980s as the Revolutionary bicentennial set off a wave of patriotism and alerted Americans to the destruction of their physical heritage. The tradition of restoring homes of the past and designating them as museums draws on the English custom of preserving ancient buildings and monuments. Initially homes were considered worthy of saving because of their associations with important individuals, usually of the elite classes, like former presidents, authors, or businessmen. Increasingly, Americans have fought to preserve structures characteristic of a more typical American past that represents the lives of everyday people including minorities.^[25]

While historic house museums compose the largest section within the historic museum category they usually operate with small staffs and on limited budgets. Many are run entirely by volunteers and often do not meet the professional standards established by the museum industry. An independent survey conducted by Peggy Coats in 1990 revealed that sixty-five percent of historic house museums did not have a full time staff and 19 to 27 percent of historic homes employed only one full time employee. Furthermore, the majority of these museums operated on less than $50,000 annually. The survey also revealed a significant disparity in the amount of visitors between local house museums and national sites. While museums like Mount Vernon and Colonial Williamsburg were visited by over one million tourists a year, more than fifty percent of historic house museums received less than 5,000 visitors per year.^[26]

These museums are also unique in that the actual structure belongs to the museum collection as a historical object. While some historic home museums are fortunate to possess a collection containing many of the original furnishings once present in the home, many face the challenge of displaying a collection consistent with the historical structure. Some museums choose to collect pieces original to the period while not original to the house. Others, fill the home with replicas of the original pieces reconstructed with the help of historic records. Still other museums adopt a more aesthetic approach and use the homes to display the architecture and artistic objects.^[27] Because historic homes have often existed through different generations and have been passed on from one family to another, volunteers and professionals also must decide which historical narrative to tell their visitors. Some museums grapple with this issue by displaying different eras in the home’s history within different rooms or sections of the structure. Others choose one particular narrative, usually the one deemed most historically significant, and restore the home to that particular period.

History museums[link]

Museum of the Filipino People, Manila, Philippines.

History museums cover the knowledge of history and its relevance to the present and future. Some cover specialized curatorial aspects of history or a particular locality; others are more general. Such museums contain a wide range of objects, including documents, artifacts of all kinds, art, archaeological objects. Antiquities museums specialize in more archaeological findings.

A common type of history museum is a historic house. A historic house may be a building of special architectural interest, the birthplace or home of a famous person, or a house with an interesting history. Historic sites can also become museums, particularly those that mark public crimes, such as Tuol Sleng Genocide Museum or Robben Island. Another type of history museum is a living museum. A living museum is where people recreate a time period to the fullest extent, including buildings, and language. It is similar to historical reenactment.

Living history museums[link]

Living history museums recreate historical settings to simulate past time periods, providing visitors with an experiential interpretation of history.^[28] These museums feature reconstructions of particular time periods and/or locations and are staffed by historical site interpreters who often reflect the time period. To reflect the time period, interpreters use costumes, period speech, and character impersonations while performing daily tasks and crafts of the period. These museums have found particular popularity in the United States and Canada.^[29]

The beginnings of the living history museum can be traced back to 1873 with the opening of the Skansen Museum near Stockholm, Sweden. The museum’s founder, Arthur Hazelius, began the museum by using his personal collection of buildings and other cultural materials of pre-industrial society.^[30] This museum began as an open air museum and, by 1891, had several farm buildings in which visitors could see exhibits and where guides demonstrated crafts and tools.^[29]

For years, living history museums were relatively nonexistent outside of Scandinavia, though some military garrisons in North America used some living history techniques.^[29] However, the growth of new social history beginning in the 1960s and 1970s and excitement over the United States Bicentennial in 1976 gave living history displays new credibility and use. Since this time, living history museums have become more widespread. Some of these first museums that are now well known in the United States are Colonial Williamsburg, Plimoth Plantation, Connor Prairie Pioneer Settlement, and Old Sturbridge Village. Many living history farms and similar farm and agricultural museums have united under an association known as the Association for Living History, Farm, and Agricultural Museums (ALHFAM).^[30]

The relative authenticity of living history farms varies significantly. At its best, they most accurately reflect the past appropriate to the time period while at their worst they may portray gross inaccuracies in an attempt to portray a certain idealized image. One such example is Wichita’s Old Cowtown Museum, which in its small, rural representation of Wichita resembles Western movies and Wild West myths more than the bustling urban city that Wichita quickly became. This living history narrative developed because of the availability of small historical buildings and inaccurate replicas, prodding from the city, and the influence of Hollywood.^[31] Museum professionals must grapple with these issues of conflicting audience and institutional needs which impact the overall structure of living history. Living history museums have also been criticized for their ability to teach, particularly from those that believe “living history is antiquarian, idyllic, or downright misleading.”^[30] In response to this question, the Association for Living History, Farm, and Agricultural Museums (ALHFAM) has stated that they distinguish between an unchanging past and an interpretation of a constantly changing past. It additionally was affirmed by the ALHFAM that they also support Dr. Scott Magelssen’s idea that living history museums produce history as others do, such as teachers in classrooms, authors in monographs, and even directors in film.^[30]

Anothter interesting example of a living museum; on 01/17/2012 conceptual artist Genco Gülan manifested at Galeri Artist Berlin that he is “the First Living Art Museum” (Erstes lebendes Kunstmuseum).

Maritime museums[link]

Maritime museums are museums that specialize in the presentation of maritime history, culture or archaeology. They explore the relationship between societies and certain bodies of water. Just as there is a vide variety of museum types, there are also many different types of maritime museums. First, as metioned above, maritime museums can be primarily archaeological. These museums focus on the interpretation and preservation of shipwrecks and other artifacts recovered from a maritime setting. A second type is the maritime history museum, dedicated to educating the public about humanity's maritime past. Examples are the San Francisco Maritime Museum and Mystic Seaport. Military-focused maritime museums are a third variety, of which the Intrepid Sea, Air and Space Museum is an example.

Military and war museums[link]

The Canadian War Museum

Military museums specialize in military histories; they are often organized from a national point of view, where a museum in a particular country will have displays organized around conflicts in which that country has taken part. They typically include displays of weapons and other military equipment, uniforms, wartime propaganda and exhibits on civilian life during wartime, and decorations, among others. A military museum may be dedicated to a particular or area, such as the Imperial War Museum Duxford for military aircraft, Deutsches Panzermuseum for tanks or the International Spy Museum for espionage, The National World War I Museum for World War I or more generalist, such as the Canadian War Museum or the Musée de l'Armée.

Mobile museums[link]

Mobile museum is a term applied to museums that make exhibitions from a vehicle, such as a van. Some institutions, such as St. Vital Historical Society and the Walker Art Center, use the term to refer to a portion of their collection that travels to sites away from the museum for educational purposes. Other mobile museums have no "home site", and use travel as their exclusive means of presentation.

Natural history museums[link]

The National Museum of Natural History in Washington, D.C.

Museums of natural history and natural science typically exhibit work of the natural world. The focus lies on nature and culture. Exhibitions educate the public on natural history, dinosaurs, zoology, oceanography, anthropology and more. Evolution, environmental issues, and biodiversity are major areas in natural science museums. Notable museums include the Natural History Museum in London, the Oxford University Museum of Natural History in Oxford, the Muséum national d'histoire naturelle in Paris, the Smithsonian Institution's National Museum of Natural History in Washington, D.C., the American Museum of Natural History in New York City, the Royal Tyrrell Museum of Palaeontology in Drumheller, Alberta, Denver Museum of Nature and Science and the Field Museum of Natural History in Chicago. A rather minor Natural history museum is The Midwest Museum of Natural History is located in Sycamore, Illinois.

Open-air museums[link]

The open-air museum of King Oscar II at Bygdøy near Oslo in the museum guide of 1888. The World's first open-air museum was founded in 1881.

An old farmhouse at the Salzburger Freilichtmuseum in Großgmain near Salzburg.

Open-air museums collect and re-erect old buildings at large outdoor sites, usually in settings of re-created landscapes of the past. The first one was King Oscar II's collection near Oslo in Norway, opened in 1881. In 1907 it was incorporated into the Norsk Folkemuseum.^[32] In 1891, inspired by a visit to the open-air museum in Oslo, Artur Hazelius founded the Skansen in Stockholm, which became the model for subsequent open-air museums in Northern and Eastern Europe, and eventually in other parts of the world.^[33] Most open-air museums are located in regions where wooden architecture prevail, as wooden structures may be translocated without substantial loss of authenticity.^{[citation needed]} A more recent but related idea is realized in ecomuseums, which originated in France.^{[citation needed]}

Pop-up museums[link]

A concept developed in the 1990s, the pop-up museum is generally defined as a short term institution existing in a temporary space.^[34] These temporary museums are finding increasing favor among more progressive museum professionals as a means of direct community involvement with objects and exhibition. Often, the pop-up concept relies solely on visitors to provide both the objects on display and the accompanying labels with the professionals or institution providing only the theme of the pop-up and the space in which to display the objects, an example of shared historical authority.. Due to the flexibility of the pop-up museums and their rejection of traditional structure, even these latter provisions need not be supplied by an institution; in some cases the themes have been chosen collectively by a committee of interested participants while exhibitions designated as pop-ups have been mounted in places as varied as community centers and even a walk-in closet.^[35] Some examples of pop-up museums include:

• Museum Of New Art (MONA)- founded in Detroit, Michigan in 1996 this contemporary art museum is generally acknowledged to be the pioneer of the concept of the pop-up museum.^[35]
• The Pop-Up Museum of Queer History- a series of pop-up museum events held at various sites across the United States focusing on the history and stories of local LGBT communities.^[36]
• Denver Community Museum- a pop-up museum that existed for nine months during 2008-9, located in downtown Denver, Colorado.^[37]

Science museums[link]

Museum of Science and Industry

Science museums and technology centers revolve around scientific achievements, and marvels and their history. To explain complicated inventions, a combination of demonstrations, interactive programs and thought-provoking media are used. Some museums may have exhibits on topics such as computers, aviation, railway museums, physics, astronomy, and the animal kingdom.

Science museums, in particular, may consist of planetaria, or large theatre usually built around a dome. Museums may have IMAX feature films, which may provide 3-D viewing or higher quality picture. As a result, IMAX content provides a more immersive experience for people of all ages.

Also new virtual museums, known as Net Museums, have recently been created. These are usually web sites belonging to real museums and containing photo galleries of items found in those real museums. This new presentation is very useful for people living far away who wish to see the contents of these museums. The German Museum in Munich, Germany is currently the world's largest museum of technology and science.

Specialized museums[link]

Antique cuckoo clocks in the interior of Cuckooland Museum.

A number of different museums exist to demonstrate a variety of topics. Music museums may celebrate the life and work of composers or musicians, such as the Rock and Roll Hall of Fame in Cleveland, Ohio, or even Rimsky-Korsakov Apartment and Museum in St Petersburg (Russia). Other music museums include live music recitals such as the Handel House Museum in London.

In Glendale, Arizona the Bead Museum^[38] fosters an appreciation and understanding of the global, historical, cultural, and artistic significance of beads and related artifacts dating as far back as 15,000 years. Also residing in the American Southwest are living history towns such as Tombstone, Arizona. This historical town is home to a number of "living history" museums (such as the O.K. Corral and the Tombstone Epitaph) in which visitors can learn about historical events from actors playing the parts of historical figures like Wyatt Earp, Doc Holiday, and John Clum. Colonial Williamsburg (in Williamsburg, Virginia), is another great example of a town devoted to preserving the story of America through reenactment.

Another example of a specialized museum, in this case devoted to horology, is the Cuckooland Museum in the United Kingdom, which hosts the world's largest and finest collection of antique cuckoo clocks.^[39]

Korea is host to the world's first museum devoted to the history and development of organic farming, the Namyangju Organic Museum, with exhibit captions in both Korean and English, and which opened in 2011.^[40]

Museums targeted for youth, such as children's museums or toy museums in many parts of the world, often exhibit interactive and educational material on a wide array of topics, for example, the Museum of Toys and Automata in Spain. The National Baseball Hall of Fame and Museum is an institution of the sports category. The Corning Museum of Glass is devoted to the art, history, and science of glass. The National Museum of Crime & Punishment explores the science of solving crimes. The Great American Dollhouse Museum in Danville, Kentucky, U.S.A., depicts American social history in miniature.^[41] Interpretation centres are modern museums or visitors centres that often use new means of communication with the public. In some cases, museums cover an extremely wide range of topics together, such as the Museum of World Treasures in Wichita, KS. In other instances, museums emphasize regional culture and natural history, such as the Regional Museum of the National University of San Martin, Tarapoto, Peru.

Virtual museums[link]

A recent development, with the expansion of the web, is the establishment of virtual museums. Online initiatives like the Virtual Museum of Canada^[42] and the National Museum of the United States Air Force provide physical museums with a web presence, as well as online curatorial platforms such as Rhizome.^[43]

Some virtual museums have no counterpart in the real world, such as LIMAC (Museo de Arte Contemporáneo de Lima),^[44] which has no physical location and might be confused with the city's own museum. The art historian Griselda Pollock elaborated a virtual feminist museum, spreading between classical art to contemporary art.^[45]

Some real life museums are also using the internet for virtual tours and exhibitions. On March 23, Whitney Museum in New York organized what it called the first ever online Twitter museum tour.

Zoological parks and botanic gardens[link]

Zoos are considered "living museums"

Although zoos and botanic gardens are not often thought of as museums, they are in fact "living museums". They exist for the same purpose as other museums: to educate, inspire action, and to study, develop and manage collections. They are also managed much like other museums and face the same challenges. Notable zoos include the Bronx Zoo in New York, the London Zoo, the Los Angeles Zoo, the Philadelphia Zoo, the Saint Louis Zoological Park, the San Diego Zoo, Berlin Zoological Garden, the Taronga Zoo in Sydney, Frankfurt Zoological Garden, Jardin des Plantes in Paris, and Zürich Zoologischer Garten in Switzerland. Notable botanic gardens include Royal Botanic Gardens Kew, Missouri Botanical Garden in St. Louis, Brooklyn Botanic Garden, Chicago Botanic Garden and Royal Botanical Gardens (Ontario).

Most visited museums[link]

See also[link]

• Audio tour
• Cell phone tour
• Exhibition history
• Ennigaldi-Nanna's museum, world's first museum
• Fire Museum
• Green museum
• International Council of Museums
• International Museum Day (May 18)
• List of museums
• List of transport museums
• Museum education
• Museum label
• Police Museum
• Postal museum
• Public memory
• Virtual Library museums pages

References[link]

Further reading[link]

• Bennett, Tony (1995). The Birth of the Museum: History, Theory, Politics. London: Routledge. ISBN 978-0-415-05387-7. OCLC 30624669. 
• Jørgen Riber (2011). "Four Steps in the History of Museum Technologies and Visitors' Digital Participation," MedieKultur 27, no. 50, pp. 7-29. ISSN 1901-9726
• Marotta, Antonello (2010). Contemporary Milan. ISBN 978-88-572-0258-7. 
• Rentzhog, Sten (2007). Open air museums: The history and future of a visionary idea. Stockholm and Östersund: Carlssons Förlag / Jamtli. ISBN 978-91-7948-208-4
• Simon, Nina K. (2010). The Participatory Museum. Santa Cruz: Museums 2.0

External links[link]

• International Council of Museums
• VLmp directory of museums
• Museums at the Open Directory Project
• Media related to Museums at Wikimedia Commons

Computing hardware is a platform for information processing (block diagram)

The history of computing hardware is the record of the ongoing effort to make computer hardware faster, cheaper, and capable of storing more data.

Computing hardware evolved from machines that needed separate manual action to perform each arithmetic operation, to punched card machines, and then to stored-program computers. The history of stored-program computers relates first to computer architecture, that is, the organization of the units to perform input and output, to store data and to operate as an integrated mechanism (see block diagram to the right). Secondly, this is a history of the electronic components and mechanical devices that comprise these units. Finally, we describe the continuing integration of 21st-century supercomputers, networks, personal devices, and integrated computers/communicators into many aspects of today's society. Increases in speed and memory capacity, and decreases in cost and size in relation to compute power, are major features of the history. As all computers rely on digital storage, and tend to be limited by the size and speed of memory, the history of computer data storage is tied to the development of computers.

Overview[link]

Before the development of the general-purpose computer, most calculations were done by humans. Mechanical tools to help humans with digital calculations were then called "calculating machines", by proprietary names, or even as they are now, calculators. It was those humans who used the machines who were then called computers; there are pictures of enormous rooms filled with desks at which computers (often young women) used their machines to jointly perform calculations, as for instance, aerodynamic ones required in aircraft design.

Calculators have continued to develop, but computers add the critical element of conditional response and larger memory, allowing automation of both numerical calculation and in general, automation of many symbol-manipulation tasks. Computer technology has undergone profound changes every decade since the 1940s.

Computing hardware has become a platform for uses other than mere computation, such as process automation, electronic communications, equipment control, entertainment, education, etc. Each field in turn has imposed its own requirements on the hardware, which has evolved in response to those requirements, such as the role of the touch screen to create a more intuitive and natural user interface.

Aside from written numerals, the first aids to computation were purely mechanical devices which required the operator to set up the initial values of an elementary arithmetic operation, then manipulate the device to obtain the result. A sophisticated (and comparatively recent) example is the slide rule in which numbers are represented as lengths on a logarithmic scale and computation is performed by setting a cursor and aligning sliding scales, thus adding those lengths. Numbers could be represented in a continuous "analog" form, for instance a voltage or some other physical property was set to be proportional to the number. Analog computers, like those designed and built by Vannevar Bush before World War II were of this type. Numbers could be represented in the form of digits, automatically manipulated by a mechanical mechanism. Although this last approach required more complex mechanisms in many cases, it made for greater precision of results.

Both analog and digital mechanical techniques continued to be developed, producing many practical computing machines. Electrical methods rapidly improved the speed and precision of calculating machines, at first by providing motive power for mechanical calculating devices, and later directly as the medium for representation of numbers. Numbers could be represented by voltages or currents and manipulated by linear electronic amplifiers. Or, numbers could be represented as discrete binary or decimal digits, and electrically controlled switches and combinational circuits could perform mathematical operations.

The invention of electronic amplifiers made calculating machines much faster than their mechanical or electromechanical predecessors. Vacuum tube (thermionic valve) amplifiers gave way to solid state transistors, and then rapidly to integrated circuits which continue to improve, placing millions of electrical switches (typically transistors) on a single elaborately manufactured piece of semi-conductor the size of a fingernail. By defeating the tyranny of numbers, integrated circuits made high-speed and low-cost digital computers a widespread commodity.

Earliest true hardware[link]

Devices have been used to aid computation for thousands of years, mostly using one-to-one correspondence with our fingers. The earliest counting device was probably a form of tally stick. Later record keeping aids throughout the Fertile Crescent included calculi (clay spheres, cones, etc.) which represented counts of items, probably livestock or grains, sealed in containers.^[1][2] The use of counting rods is one example.

The abacus was early used for arithmetic tasks. What we now call the Roman abacus was used in Babylonia as early as 2400 BC. Since then, many other forms of reckoning boards or tables have been invented. In a medieval European counting house, a checkered cloth would be placed on a table, and markers moved around on it according to certain rules, as an aid to calculating sums of money.

Several analog computers were constructed in ancient and medieval times to perform astronomical calculations. These include the Antikythera mechanism and the astrolabe from ancient Greece (c. 150–100 BC), which are generally regarded as the earliest known mechanical analog computers.^[3] Hero of Alexandria (c. 10–70 AD) made many complex mechanical devices including automata and a programmable cart.^[4] Other early versions of mechanical devices used to perform one or another type of calculations include the planisphere and other mechanical computing devices invented by Abū Rayhān al-Bīrūnī (c. AD 1000); the equatorium and universal latitude-independent astrolabe by Abū Ishāq Ibrāhīm al-Zarqālī (c. AD 1015); the astronomical analog computers of other medieval Muslim astronomers and engineers; and the astronomical clock tower of Su Song (c. AD 1090) during the Song Dynasty.

Suanpan (the number represented on this abacus is 6,302,715,408)

Scottish mathematician and physicist John Napier noted multiplication and division of numbers could be performed by addition and subtraction, respectively, of logarithms of those numbers. While producing the first logarithmic tables Napier needed to perform many multiplications, and it was at this point that he designed Napier's bones, an abacus-like device used for multiplication and division.^[5] Since real numbers can be represented as distances or intervals on a line, the slide rule was invented in the 1620s to allow multiplication and division operations to be carried out significantly faster than was previously possible.^[6] Slide rules were used by generations of engineers and other mathematically involved professional workers, until the invention of the pocket calculator.^[7]

Yazu Arithmometer. Patented in Japan in 1903. Note the lever for turning the gears of the calculator.

Wilhelm Schickard, a German polymath, designed a calculating clock in 1623. It made use of a single-tooth gear that was not an adequate solution for a general carry mechanism.^[8] A fire destroyed the machine during its construction in 1624 and Schickard abandoned the project. Two sketches of it were discovered in 1957, too late to have any impact on the development of mechanical calculators.^[9]

In 1642, while still a teenager, Blaise Pascal started some pioneering work on calculating machines and after three years of effort and 50 prototypes^[10] he invented the mechanical calculator.^[11][12] He built twenty of these machines (called Pascal's Calculator or Pascaline) in the following ten years.^[13] Nine Pascalines have survived, most of which are on display in European museums.^[14]

Gottfried Wilhelm von Leibniz invented the Stepped Reckoner and his famous cylinders around 1672 while adding direct multiplication and division to the Pascaline. Leibniz once said "It is unworthy of excellent men to lose hours like slaves in the labour of calculation which could safely be relegated to anyone else if machines were used."^[15]

Around 1820, Charles Xavier Thomas created the first successful, mass-produced mechanical calculator, the Thomas Arithmometer, that could add, subtract, multiply, and divide.^[16] It was mainly based on Leibniz' work. Mechanical calculators, like the base-ten addiator, the comptometer, the Monroe, the Curta and the Addo-X remained in use until the 1970s. Leibniz also described the binary numeral system,^[17] a central ingredient of all modern computers. However, up to the 1940s, many subsequent designs (including Charles Babbage's machines of the 1822 and even ENIAC of 1945) were based on the decimal system;^[18] ENIAC's ring counters emulated the operation of the digit wheels of a mechanical adding machine.

In Japan, Ryōichi Yazu patented a mechanical calculator called the Yazu Arithmometer in 1903. It consisted of a single cylinder and 22 gears, and employed the mixed base-2 and base-5 number system familiar to users to the soroban (Japanese abacus). Carry and end of calculation were determined automatically.^[19] More than 200 units were sold, mainly to government agencies such as the Ministry of War and agricultural experiment stations.^[20][21]

1801: punched card technology[link]

Main article: Analytical Engine. See also: Logic piano

Punched card system of a music machine, also referred to as Book music

In 1801, Joseph-Marie Jacquard developed a loom in which the pattern being woven was controlled by punched cards. The series of cards could be changed without changing the mechanical design of the loom. This was a landmark achievement in programmability. His machine was an improvement over similar weaving looms. Punch cards were preceded by punch bands, as in the machine proposed by Basile Bouchon. These bands would inspire information recording for automatic pianos and more recently NC machine-tools.

In 1833, Charles Babbage moved on from developing his difference engine (for navigational calculations) to a general purpose design, the Analytical Engine, which drew directly on Jacquard's punched cards for its program storage.^[22] In 1837, Babbage described his analytical engine. It was a general-purpose programmable computer, employing punch cards for input and a steam engine for power, using the positions of gears and shafts to represent numbers.^[23] His initial idea was to use punch-cards to control a machine that could calculate and print logarithmic tables with huge precision (a special purpose machine). Babbage's idea soon developed into a general-purpose programmable computer. While his design was sound and the plans were probably correct, or at least debuggable, the project was slowed by various problems including disputes with the chief machinist building parts for it. Babbage was a difficult man to work with and argued with everyone. All the parts for his machine had to be made by hand. Small errors in each item might sometimes sum to cause large discrepancies. In a machine with thousands of parts, which required these parts to be much better than the usual tolerances needed at the time, this was a major problem. The project dissolved in disputes with the artisan who built parts and ended with the decision of the British Government to cease funding. Ada Lovelace, Lord Byron's daughter, translated and added notes to the "Sketch of the Analytical Engine" by Federico Luigi, Conte Menabrea. This appears to be the first published description of programming.^[24]

A reconstruction of the Difference Engine II, an earlier, more limited design, has been operational since 1991 at the London Science Museum. With a few trivial changes, it works exactly as Babbage designed it and shows that Babbage's design ideas were correct, merely too far ahead of his time. The museum used computer-controlled machine tools to construct the necessary parts, using tolerances a good machinist of the period would have been able to achieve. Babbage's failure to complete the analytical engine can be chiefly attributed to difficulties not only of politics and financing, but also to his desire to develop an increasingly sophisticated computer and to move ahead faster than anyone else could follow.

A machine based on Babbage's difference engine was built in 1843 by Per Georg Scheutz and his son Edward. An improved Scheutzian calculation engine was sold to the British government and a later model was sold to the American government and these were used successfully in the production of logarithmic tables.^[25][26]

Following Babbage, although unaware of his earlier work, was Percy Ludgate, an accountant from Dublin, Ireland. He independently designed a programmable mechanical computer, which he described in a work that was published in 1909.

1880s: punched card data storage[link]

IBM punched card Accounting Machines at the U.S. Social Security Administration in 1936.

In the late 1880s, the American Herman Hollerith invented data storage on a medium that could then be read by a machine. Prior uses of machine readable media had been for control (automatons such as piano rolls or looms), not data. "After some initial trials with paper tape, he settled on punched cards..."^[27] Hollerith came to use punched cards after observing how railroad conductors encoded personal characteristics of each passenger with punches on their tickets. To process these punched cards he invented the tabulator, and the key punch machine. These three inventions were the foundation of the modern information processing industry. His machines used mechanical relays (and solenoids) to increment mechanical counters. Hollerith's method was used in the 1890 United States Census and the completed results were "... finished months ahead of schedule and far under budget".^[28] Indeed, the census was processed years faster than the prior census had been. Hollerith's company eventually became the core of IBM. IBM developed punch card technology into a powerful tool for business data-processing and produced an extensive line of unit record equipment. By 1950, the IBM card had become ubiquitous in industry and government. The warning printed on most cards intended for circulation as documents (checks, for example), "Do not fold, spindle or mutilate," became a catch phrase for the post-World War II era.^[29]

Punch card Tabulator

Punched card with the extended alphabet

Leslie Comrie's articles on punched card methods and W.J. Eckert's publication of Punched Card Methods in Scientific Computation in 1940, described punch card techniques sufficiently advanced to solve some differential equations^[30] or perform multiplication and division using floating point representations, all on punched cards and unit record machines. Those same machines had been used during World War II for cryptographic statistical processing. In the image of the tabulator (see left), note the control panel, which is visible on the right side of the tabulator. A row of toggle switches is above the control panel. The Thomas J. Watson Astronomical Computing Bureau, Columbia University performed astronomical calculations representing the state of the art in computing.^[31]

Computer programming in the punch card era was centered in the "computer center". Computer users, for example science and engineering students at universities, would submit their programming assignments to their local computer center in the form of a deck of punched cards, one card per program line. They then had to wait for the program to be read in, queued for processing, compiled, and executed. In due course, a printout of any results, marked with the submitter's identification, would be placed in an output tray, typically in the computer center lobby. In many cases these results would be only a series of error messages, requiring yet another edit-punch-compile-run cycle.^[32] Punched cards are still used and manufactured to this day, and their distinctive dimensions (and 80-column capacity) can still be recognized in forms, records, and programs around the world. They are the size of American paper currency in Hollerith's time, a choice he made because there was already equipment available to handle bills.

Desktop calculators[link]

The Curta calculator can also do multiplication and division.

By the 20th century, earlier mechanical calculators, cash registers, accounting machines, and so on were redesigned to use electric motors, with gear position as the representation for the state of a variable. The word "computer" was a job title assigned to people who used these calculators to perform mathematical calculations. By the 1920s Lewis Fry Richardson's interest in weather prediction led him to propose human computers and numerical analysis to model the weather; to this day, the most powerful computers on Earth are needed to adequately model its weather using the Navier–Stokes equations.^[33]

Companies like Friden, Marchant Calculator and Monroe made desktop mechanical calculators from the 1930s that could add, subtract, multiply and divide. During the Manhattan project, future Nobel laureate Richard Feynman was the supervisor of human computers who understood the use of differential equations which were being solved for the war effort.

In 1948, the Curta was introduced. This was a small, portable, mechanical calculator that was about the size of a pepper grinder. Over time, during the 1950s and 1960s a variety of different brands of mechanical calculators appeared on the market. The first all-electronic desktop calculator was the British ANITA Mk.VII, which used a Nixie tube display and 177 subminiature thyratron tubes. In June 1963, Friden introduced the four-function EC-130. It had an all-transistor design, 13-digit capacity on a 5-inch (130 mm) CRT, and introduced Reverse Polish notation (RPN) to the calculator market at a price of $2200. The EC-132 model added square root and reciprocal functions. In 1965, Wang Laboratories produced the LOCI-2, a 10-digit transistorized desktop calculator that used a Nixie tube display and could compute logarithms.

In the early days of binary vacuum-tube computers, their reliability was poor enough to justify marketing a mechanical octal version ("Binary Octal") of the Marchant desktop calculator. It was intended to check and verify calculation results of such computers.

Advanced analog computers[link]

Cambridge differential analyzer, 1938

Before World War II, mechanical and electrical analog computers were considered the "state of the art", and many thought they were the future of computing. Analog computers take advantage of the strong similarities between the mathematics of small-scale properties—the position and motion of wheels or the voltage and current of electronic components—and the mathematics of other physical phenomena, for example, ballistic trajectories, inertia, resonance, energy transfer, momentum, and so forth. They model physical phenomena with electrical voltages and currents^[34] as the analog quantities.

Centrally, these analog systems work by creating electrical 'analogs' of other systems, allowing users to predict behavior of the systems of interest by observing the electrical analogs.^[35] The most useful of the analogies was the way the small-scale behavior could be represented with integral and differential equations, and could be thus used to solve those equations. An ingenious example of such a machine, using water as the analog quantity, was the water integrator built in 1928; an electrical example is the Mallock machine built in 1941. A planimeter is a device which does integrals, using distance as the analog quantity. Unlike modern digital computers, analog computers are not very flexible, and need to be rewired manually to switch them from working on one problem to another. Analog computers had an advantage over early digital computers in that they could be used to solve complex problems using behavioral analogues while the earliest attempts at digital computers were quite limited.

Some of the most widely deployed analog computers included devices for aiming weapons, such as the Norden bombsight,^[36] and fire-control systems,^[37] such as Arthur Pollen's Argo system for naval vessels. Some stayed in use for decades after World War II; the Mark I Fire Control Computer was deployed by the United States Navy on a variety of ships from destroyers to battleships. Other analog computers included the Heathkit EC-1, and the hydraulic MONIAC Computer which modeled econometric flows.^[38]

The art of mechanical analog computing reached its zenith with the differential analyzer,^[39] built by H. L. Hazen and Vannevar Bush at MIT starting in 1927, which in turn built on the mechanical integrators invented in 1876 by James Thomson and the torque amplifiers invented by H. W. Nieman. A dozen of these devices were built before their obsolescence was obvious; the most powerful was constructed at the University of Pennsylvania's Moore School of Electrical Engineering, where the ENIAC was built. Digital electronic computers like the ENIAC spelled the end for most analog computing machines, but hybrid analog computers, controlled by digital electronics, remained in substantial use into the 1950s and 1960s, and later in some specialized applications.

Early electronic digital computation[link]

Friden paper tape punch. Punched tape programs would be much longer than the short fragment of yellow paper tape shown.

The era of modern computing began with a flurry of development before and during World War II, as electronic circuit elements replaced mechanical equivalents, and digital calculations replaced analog calculations. Machines such as the Z3, the Atanasoff–Berry Computer, the Colossus computers, and the ENIAC were built by hand using circuits containing relays or valves (vacuum tubes), and often used punched cards or punched paper tape for input and as the main (non-volatile) storage medium. Defining a single point in the series as the "first computer" misses many subtleties (see the table "Defining characteristics of some early digital computers of the 1940s" below).

Alan Turing's 1936 paper^[40] proved enormously influential in computing and computer science in two ways. Its main purpose was to prove that there were problems (namely the halting problem) that could not be solved by any sequential process. In doing so, Turing provided a definition of a universal computer which executes a program stored on tape. This construct came to be called a Turing machine.^[41] Except for the limitations imposed by their finite memory stores, modern computers are said to be Turing-complete, which is to say, they have algorithm execution capability equivalent to a universal Turing machine.

Half-inch (12.7 mm) magnetic tape, originally written with 7 tracks and later 9-tracks.

For a computing machine to be a practical general-purpose computer, there must be some convenient read-write mechanism, punched tape, for example. With knowledge of Alan Turing's theoretical 'universal computing machine' John von Neumann defined an architecture which uses the same memory both to store programs and data: virtually all contemporary computers use this architecture (or some variant). While it is theoretically possible to implement a full computer entirely mechanically (as Babbage's design showed), electronics made possible the speed and later the miniaturization that characterize modern computers.

There were three parallel streams of computer development in the World War II era; the first stream largely ignored, and the second stream deliberately kept secret. The first was the German work of Konrad Zuse. The second was the secret development of the Colossus computers in the UK. Neither of these had much influence on the various computing projects in the United States. The third stream of computer development, Eckert and Mauchly's ENIAC and EDVAC, was widely publicized.^[42][43]

George Stibitz is internationally recognized as one of the fathers of the modern digital computer. While working at Bell Labs in November 1937, Stibitz invented and built a relay-based calculator that he dubbed the "Model K" (for "kitchen table", on which he had assembled it), which was the first to calculate using binary form.^[44]

Zuse[link]

A reproduction of Zuse's Z1 computer

Working in isolation in Germany, Konrad Zuse started construction in 1936 of his first Z-series calculators featuring memory and (initially limited) programmability. Zuse's purely mechanical, but already binary Z1, finished in 1938, never worked reliably due to problems with the precision of parts.

Zuse's later machine, the Z3,^[45] was finished in 1941. It was based on telephone relays and did work satisfactorily. The Z3 thus became the first functional program-controlled, all-purpose, digital computer. In many ways it was quite similar to modern machines, pioneering numerous advances, such as floating point numbers. Replacement of the hard-to-implement decimal system (used in Charles Babbage's earlier design) by the simpler binary system meant that Zuse's machines were easier to build and potentially more reliable, given the technologies available at that time.

Programs were fed into Z3 on punched films. Conditional jumps were missing, but since the 1990s it has been proved theoretically that Z3 was still a universal computer (as always, ignoring physical storage limitations). In two 1936 patent applications, Konrad Zuse also anticipated that machine instructions could be stored in the same storage used for data—the key insight of what became known as the von Neumann architecture, first implemented in the British SSEM of 1948.^[46] Zuse also claimed to have designed the first higher-level programming language, which he named Plankalkül, in 1945 (published in 1948) although it was implemented for the first time in 2000 by a team around Raúl Rojas at the Free University of Berlin—five years after Zuse died.

Zuse suffered setbacks during World War II when some of his machines were destroyed in the course of Allied bombing campaigns. Apparently his work remained largely unknown to engineers in the UK and US until much later, although at least IBM was aware of it as it financed his post-war startup company in 1946 in return for an option on Zuse's patents.

Colossus[link]

Colossus was used to break German ciphers during World War II.

During World War II, the British at Bletchley Park (40 miles north of London) achieved a number of successes at breaking encrypted German military communications. The German encryption machine, Enigma, was attacked with the help of electro-mechanical machines called bombes. The bombe, designed by Alan Turing and Gordon Welchman, after the Polish cryptographic bomba by Marian Rejewski (1938), came into productive use in 1941.^[47] They ruled out possible Enigma settings by performing chains of logical deductions implemented electrically. Most possibilities led to a contradiction, and the few remaining could be tested by hand.

The Germans also developed a series of teleprinter encryption systems, quite different from Enigma. The Lorenz SZ 40/42 machine was used for high-level Army communications, termed "Tunny" by the British. The first intercepts of Lorenz messages began in 1941. As part of an attack on Tunny, Professor Max Newman and his colleagues helped specify the Colossus.^[48] The Mk I Colossus was built between March and December 1943 by Tommy Flowers and his colleagues at the Post Office Research Station at Dollis Hill in London and then shipped to Bletchley Park in January 1944.

Colossus was the world's first electronic programmable computing device. It used a large number of valves (vacuum tubes). It had paper-tape input and was capable of being configured to perform a variety of boolean logical operations on its data, but it was not Turing-complete. Nine Mk II Colossi were built (The Mk I was converted to a Mk II making ten machines in total). Details of their existence, design, and use were kept secret well into the 1970s. Winston Churchill personally issued an order for their destruction into pieces no larger than a man's hand, to keep secret that the British were capable of cracking Lorenz during the oncoming cold war. Two of the machines were transferred to the newly formed GCHQ and the others were destroyed. As a result the machines were not included in many histories of computing. A reconstructed working copy of one of the Colossus machines is now on display at Bletchley Park.

American developments[link]

In 1937, Claude Shannon showed there is a one-to-one correspondence between the concepts of Boolean logic and certain electrical circuits, now called logic gates, which are now ubiquitous in digital computers.^[49] In his master's thesis^[50] at MIT, for the first time in history, Shannon showed that electronic relays and switches can realize the expressions of Boolean algebra. Entitled A Symbolic Analysis of Relay and Switching Circuits, Shannon's thesis essentially founded practical digital circuit design. George Stibitz completed a relay-based computer he dubbed the "Model K" at Bell Labs in November 1937. Bell Labs authorized a full research program in late 1938 with Stibitz at the helm. Their Complex Number Calculator,^[51] completed January 8, 1940, was able to calculate complex numbers. In a demonstration to the American Mathematical Society conference at Dartmouth College on September 11, 1940, Stibitz was able to send the Complex Number Calculator remote commands over telephone lines by a teletype. It was the first computing machine ever used remotely, in this case over a phone line. Some participants in the conference who witnessed the demonstration were John von Neumann, John Mauchly, and Norbert Wiener, who wrote about it in their memoirs.

Atanasoff–Berry Computer replica at 1st floor of Durham Center, Iowa State University

In 1939, John Vincent Atanasoff and Clifford E. Berry of Iowa State University developed the Atanasoff–Berry Computer (ABC),^[52] The Atanasoff-Berry Computer was the world's first electronic digital computer.^[53] The design used over 300 vacuum tubes and employed capacitors fixed in a mechanically rotating drum for memory. Though the ABC machine was not programmable, it was the first to use electronic tubes in an adder. ENIAC co-inventor John Mauchly examined the ABC in June 1941, and its influence on the design of the later ENIAC machine is a matter of contention among computer historians. The ABC was largely forgotten until it became the focus of the lawsuit Honeywell v. Sperry Rand, the ruling of which invalidated the ENIAC patent (and several others) as, among many reasons, having been anticipated by Atanasoff's work.

In 1939, development began at IBM's Endicott laboratories on the Harvard Mark I. Known officially as the Automatic Sequence Controlled Calculator,^[54] the Mark I was a general purpose electro-mechanical computer built with IBM financing and with assistance from IBM personnel, under the direction of Harvard mathematician Howard Aiken. Its design was influenced by Babbage's Analytical Engine, using decimal arithmetic and storage wheels and rotary switches in addition to electromagnetic relays. It was programmable via punched paper tape, and contained several calculation units working in parallel. Later versions contained several paper tape readers and the machine could switch between readers based on a condition. Nevertheless, the machine was not quite Turing-complete. The Mark I was moved to Harvard University and began operation in May 1944.

ENIAC[link]

ENIAC performed ballistics trajectory calculations with 160 kW of power

The US-built ENIAC (Electronic Numerical Integrator and Computer) was the first electronic general-purpose computer. It combined, for the first time, the high speed of electronics with the ability to be programmed for many complex problems. It could add or subtract 5000 times a second, a thousand times faster than any other machine. It also had modules to multiply, divide, and square root. High speed memory was limited to 20 words (about 80 bytes). Built under the direction of John Mauchly and J. Presper Eckert at the University of Pennsylvania, ENIAC's development and construction lasted from 1943 to full operation at the end of 1945. The machine was huge, weighing 30 tons, and contained over 18,000 vacuum tubes. One of the major engineering feats was to minimize tube burnout, which was a common problem at that time. The machine was in almost constant use for the next ten years.

ENIAC was unambiguously a Turing-complete device. It could compute any problem (that would fit in memory). A "program" on the ENIAC, however, was defined by the states of its patch cables and switches, a far cry from the stored program electronic machines that evolved from it. Once a program was written, it had to be mechanically set into the machine. Six women did most of the programming of ENIAC. (Improvements completed in 1948 made it possible to execute stored programs set in function table memory, which made programming less a "one-off" effort, and more systematic).

Early computer characteristics[link]

First-generation machines[link]

Design of the von Neumann architecture (1947)

Even before the ENIAC was finished, Eckert and Mauchly recognized its limitations and started the design of a stored-program computer, EDVAC. John von Neumann was credited with a widely circulated report describing the EDVAC design in which both the programs and working data were stored in a single, unified store. This basic design, denoted the von Neumann architecture, would serve as the foundation for the worldwide development of ENIAC's successors.^[55] In this generation of equipment, temporary or working storage was provided by acoustic delay lines, which used the propagation time of sound through a medium such as liquid mercury (or through a wire) to briefly store data. A series of acoustic pulses is sent along a tube; after a time, as the pulse reached the end of the tube, the circuitry detected whether the pulse represented a 1 or 0 and caused the oscillator to re-send the pulse. Others used Williams tubes, which use the ability of a small cathode-ray tube (CRT) to store and retrieve data as charged areas on the phosphor screen. By 1954, magnetic core memory^[56] was rapidly displacing most other forms of temporary storage, and dominated the field through the mid-1970s.

Magnetic core memory. Each core is one bit.

EDVAC was the first stored-program computer designed; however it was not the first to run. Eckert and Mauchly left the project and its construction floundered. The first working von Neumann machine was the Manchester "Baby" or Small-Scale Experimental Machine, developed by Frederic C. Williams and Tom Kilburn at the University of Manchester in 1948 as a test bed for the Williams tube;^[57] it was followed in 1949 by the Manchester Mark 1 computer, a complete system, using Williams tube and magnetic drum memory, and introducing index registers.^[58] The other contender for the title "first digital stored-program computer" had been EDSAC, designed and constructed at the University of Cambridge. Operational less than one year after the Manchester "Baby", it was also capable of tackling real problems. EDSAC was actually inspired by plans for EDVAC (Electronic Discrete Variable Automatic Computer), the successor to ENIAC; these plans were already in place by the time ENIAC was successfully operational. Unlike ENIAC, which used parallel processing, EDVAC used a single processing unit. This design was simpler and was the first to be implemented in each succeeding wave of miniaturization, and increased reliability. Some view Manchester Mark 1 / EDSAC / EDVAC as the "Eves" from which nearly all current computers derive their architecture. Manchester University's machine became the prototype for the Ferranti Mark 1. The first Ferranti Mark 1 machine was delivered to the University in February 1951 and at least nine others were sold between 1951 and 1957.

The first universal programmable computer in the Soviet Union was created by a team of scientists under direction of Sergei Alekseyevich Lebedev from Kiev Institute of Electrotechnology, Soviet Union (now Ukraine). The computer MESM (МЭСМ, Small Electronic Calculating Machine) became operational in 1950. It had about 6,000 vacuum tubes and consumed 25 kW of power. It could perform approximately 3,000 operations per second. Another early machine was CSIRAC, an Australian design that ran its first test program in 1949. CSIRAC is the oldest computer still in existence and the first to have been used to play digital music.^[59]

Commercial computers[link]

The first commercial computer was the Ferranti Mark 1, which was delivered to the University of Manchester in February 1951. It was based on the Manchester Mark 1. The main improvements over the Manchester Mark 1 were in the size of the primary storage (using random access Williams tubes), secondary storage (using a magnetic drum), a faster multiplier, and additional instructions. The basic cycle time was 1.2 milliseconds, and a multiplication could be completed in about 2.16 milliseconds. The multiplier used almost a quarter of the machine's 4,050 vacuum tubes (valves).^[60] A second machine was purchased by the University of Toronto, before the design was revised into the Mark 1 Star. At least seven of these later machines were delivered between 1953 and 1957, one of them to Shell labs in Amsterdam.^[61]

In October 1947, the directors of J. Lyons & Company, a British catering company famous for its teashops but with strong interests in new office management techniques, decided to take an active role in promoting the commercial development of computers. The LEO I computer became operational in April 1951 ^[62] and ran the world's first regular routine office computer job. On 17 November 1951, the J. Lyons company began weekly operation of a bakery valuations job on the LEO (Lyons Electronic Office). This was the first business application to go live on a stored program computer.^[63]

In June 1951, the UNIVAC I (Universal Automatic Computer) was delivered to the U.S. Census Bureau. Remington Rand eventually sold 46 machines at more than $1 million each ($8.95 million as of 2012).^[64] UNIVAC was the first "mass produced" computer. It used 5,200 vacuum tubes and consumed 125 kW of power. Its primary storage was serial-access mercury delay lines capable of storing 1,000 words of 11 decimal digits plus sign (72-bit words). A key feature of the UNIVAC system was a newly invented type of metal magnetic tape, and a high-speed tape unit, for non-volatile storage. Magnetic media are still used in many computers.^[65] In 1952, IBM publicly announced the IBM 701 Electronic Data Processing Machine, the first in its successful 700/7000 series and its first IBM mainframe computer. The IBM 704, introduced in 1954, used magnetic core memory, which became the standard for large machines. The first implemented high-level general purpose programming language, Fortran, was also being developed at IBM for the 704 during 1955 and 1956 and released in early 1957. (Konrad Zuse's 1945 design of the high-level language Plankalkül was not implemented at that time.) A volunteer user group, which exists to this day, was founded in 1955 to share their software and experiences with the IBM 701.

IBM 650 front panel

IBM introduced a smaller, more affordable computer in 1954 that proved very popular.^[66] The IBM 650 weighed over 900 kg, the attached power supply weighed around 1350 kg and both were held in separate cabinets of roughly 1.5 meters by 0.9 meters by 1.8 meters. It cost $500,000^[67] ($4.33 million as of 2012) or could be leased for $3,500 a month ($30 thousand as of 2012).^[64] Its drum memory was originally 2,000 ten-digit words, later expanded to 4,000 words. Memory limitations such as this were to dominate programming for decades afterward. The program instructions were fetched from the spinning drum as the code ran. Efficient execution using drum memory was provided by a combination of hardware architecture: the instruction format included the address of the next instruction; and software: the Symbolic Optimal Assembly Program, SOAP,^[68] assigned instructions to the optimal addresses (to the extent possible by static analysis of the source program). Thus many instructions were, when needed, located in the next row of the drum to be read and additional wait time for drum rotation was not required.

In 1955, Maurice Wilkes invented microprogramming,^[69] which allows the base instruction set to be defined or extended by built-in programs (now called firmware or microcode).^[70] It was widely used in the CPUs and floating-point units of mainframe and other computers, such as the Manchester Atlas ^[71] and the IBM 360 series.^[72]

IBM introduced its first magnetic disk system, RAMAC (Random Access Method of Accounting and Control) in 1956. Using fifty 24-inch (610 mm) metal disks, with 100 tracks per side, it was able to store 5 megabytes of data at a cost of $10,000 per megabyte ($90 thousand as of 2012).^[64][73]

Second generation: transistors[link]

A bipolar junction transistor

The bipolar transistor was invented in 1947. From 1955 onwards transistors replaced vacuum tubes in computer designs,^[74] giving rise to the "second generation" of computers. Initially the only devices available were germanium point-contact transistors, which although less reliable than the vacuum tubes they replaced had the advantage of consuming far less power.^[75] The first transistorised computer was built at the University of Manchester and was operational by 1953;^[76] a second version was completed there in April 1955. The later machine used 200 transistors and 1,300 solid-state diodes and had a power consumption of 150 watts. However, it still required valves to generate the clock waveforms at 125 kHz and to read and write on the magnetic drum memory, whereas the Harwell CADET operated without any valves by using a lower clock frequency, of 58 kHz when it became operational in February 1955.^[77] Problems with the reliability of early batches of point contact and alloyed junction transistors meant that the machine's mean time between failures was about 90 minutes, but this improved once the more reliable bipolar junction transistors became available.^[78]

Compared to vacuum tubes, transistors have many advantages: they are smaller, and require less power than vacuum tubes, so give off less heat. Silicon junction transistors were much more reliable than vacuum tubes and had longer, indefinite, service life. Transistorized computers could contain tens of thousands of binary logic circuits in a relatively compact space. Transistors greatly reduced computers' size, initial cost, and operating cost. Typically, second-generation computers were composed of large numbers of printed circuit boards such as the IBM Standard Modular System^[79] each carrying one to four logic gates or flip-flops.

A second generation computer, the IBM 1401, captured about one third of the world market. IBM installed more than ten thousand 1401s between 1960 and 1964.

This RAMAC DASD is being restored at the Computer History Museum

Transistorized electronics improved not only the CPU (Central Processing Unit), but also the peripheral devices. The IBM 350 RAMAC was introduced in 1956 and was the world's first disk drive. The second generation disk data storage units were able to store tens of millions of letters and digits. Next to the fixed disk storage units, connected to the CPU via high-speed data transmission, were removable disk data storage units. A removable disk stack can be easily exchanged with another stack in a few seconds. Even if the removable disks' capacity is smaller than fixed disks, their interchangeability guarantees a nearly unlimited quantity of data close at hand. Magnetic tape provided archival capability for this data, at a lower cost than disk.

Many second-generation CPUs delegated peripheral device communications to a secondary processor. For example, while the communication processor controlled card reading and punching, the main CPU executed calculations and binary branch instructions. One databus would bear data between the main CPU and core memory at the CPU's fetch-execute cycle rate, and other databusses would typically serve the peripheral devices. On the PDP-1, the core memory's cycle time was 5 microseconds; consequently most arithmetic instructions took 10 microseconds (100,000 operations per second) because most operations took at least two memory cycles; one for the instruction, one for the operand data fetch.

During the second generation remote terminal units (often in the form of teletype machines like a Friden Flexowriter) saw greatly increased use.^[80] Telephone connections provided sufficient speed for early remote terminals and allowed hundreds of kilometers separation between remote-terminals and the computing center. Eventually these stand-alone computer networks would be generalized into an interconnected network of networks—the Internet.^[81]

Post-1960: third generation and beyond[link]

Intel 8742 eight-bit microcontroller IC

The explosion in the use of computers began with "third-generation" computers, making use of Jack St. Clair Kilby's^[82] and Robert Noyce's^[83] independent invention of the integrated circuit (or microchip), which led to the invention of the microprocessor. While the subject of exactly which device was the first microprocessor is contentious, partly due to lack of agreement on the exact definition of the term "microprocessor", it is largely undisputed that the first single-chip microprocessor was the Intel 4004,^[84] designed and realized by Ted Hoff, Federico Faggin, and Stanley Mazor at Intel.^[85]

While the earliest microprocessor ICs literally contained only the processor, i.e. the central processing unit, of a computer, their progressive development naturally led to chips containing most or all of the internal electronic parts of a computer. The integrated circuit in the image on the right, for example, an Intel 8742, is an 8-bit microcontroller that includes a CPU running at 12 MHz, 128 bytes of RAM, 2048 bytes of EPROM, and I/O in the same chip.

During the 1960s there was considerable overlap between second and third generation technologies.^[86] IBM implemented its IBM Solid Logic Technology modules in hybrid circuits for the IBM System/360 in 1964. As late as 1975, Sperry Univac continued the manufacture of second-generation machines such as the UNIVAC 494. The Burroughs large systems such as the B5000 were stack machines, which allowed for simpler programming. These pushdown automatons were also implemented in minicomputers and microprocessors later, which influenced programming language design. Minicomputers served as low-cost computer centers for industry, business and universities.^[87] It became possible to simulate analog circuits with the simulation program with integrated circuit emphasis, or SPICE (1971) on minicomputers, one of the programs for electronic design automation (EDA). The microprocessor led to the development of the microcomputer, small, low-cost computers that could be owned by individuals and small businesses. Microcomputers, the first of which appeared in the 1970s, became ubiquitous in the 1980s and beyond.

In April 1975 at the Hannover Fair, was presented the P6060 produced by Olivetti, the world's first personal computer with built-in floppy disk: Central Unit on two plates, code names PUCE1/PUCE2, TTL components made, 8" single or double floppy disk driver, 32 alphanumeric characters plasma display, 80 columns graphical thermal printer, 48 Kbytes of RAM, BASIC language, 40 kilograms of weight. He was in competition with a similar product by IBM but with an external floppy disk.

MOS Technology KIM-1 and Altair 8800, were sold as kits for do-it-yourselfers, as was the Apple I, soon afterward. The first Apple computer with graphic and sound capabilities came out well after the Commodore PET. Computing has evolved with microcomputer architectures, with features added from their larger brethren, now dominant in most market segments.

Systems as complicated as computers require very high reliability. ENIAC remained on, in continuous operation from 1947 to 1955, for eight years before being shut down. Although a vacuum tube might fail, it would be replaced without bringing down the system. By the simple strategy of never shutting down ENIAC, the failures were dramatically reduced. The vacuum-tube SAGE air-defense computers became remarkably reliable – installed in pairs, one off-line, tubes likely to fail did so when the computer was intentionally run at reduced power to find them. Hot-pluggable hard disks, like the hot-pluggable vacuum tubes of yesteryear, continue the tradition of repair during continuous operation. Semiconductor memories routinely have no errors when they operate, although operating systems like Unix have employed memory tests on start-up to detect failing hardware. Today, the requirement of reliable performance is made even more stringent when server farms are the delivery platform.^[88] Google has managed this by using fault-tolerant software to recover from hardware failures, and is even working on the concept of replacing entire server farms on-the-fly, during a service event.^[89][90]

In the 21st century, multi-core CPUs became commercially available.^[91] Content-addressable memory (CAM)^[92] has become inexpensive enough to be used in networking, although no computer system has yet implemented hardware CAMs for use in programming languages. Currently, CAMs (or associative arrays) in software are programming-language-specific. Semiconductor memory cell arrays are very regular structures, and manufacturers prove their processes on them; this allows price reductions on memory products. During the 1980s, CMOS logic gates developed into devices that could be made as fast as other circuit types; computer power consumption could therefore be decreased dramatically. Unlike the continuous current draw of a gate based on other logic types, a CMOS gate only draws significant current during the 'transition' between logic states, except for leakage.

This has allowed computing to become a commodity which is now ubiquitous, embedded in many forms, from greeting cards and telephones to satellites. Computing hardware and its software have even become a metaphor for the operation of the universe.^[93] Although DNA-based computing and quantum qubit computing are years or decades in the future, the infrastructure is being laid today, for example, with DNA origami on photolithography^[94] and with quantum antennae for transferring information between ion traps.^[95] By 2011, researchers had entangled 14 qubits.^[96] Fast digital circuits (including those based on Josephson junctions and rapid single flux quantum technology) are becoming more nearly realizable with the discovery of nanoscale superconductors.^[97]

Fiber-optic and photonic devices, which already have been used to transport data over long distances, are now entering the data center, side by side with CPU and semiconductor memory components. This allows the separation of RAM from CPU by optical interconnects.^[98]

An indication of the rapidity of development of this field can be inferred by the history of the seminal article.^[99] By the time that anyone had time to write anything down, so it was obsolete. After 1945, others read John von Neumann's First Draft of a Report on the EDVAC, and immediately started implementing their own systems. To this day, the pace of development has continued, worldwide.^[100][101]

See also[link]

Computer Science portal

Notes[link]

References[link]

Further reading[link]

• Ceruzzi, Paul E., A History of Modern Computing, MIT Press, 1998

External links[link]

Wikimedia Commons has media related to: Historical computers

Wikimedia Commons has media related to: Computer modules

Wikiversity has learning materials about Introduction to Computers/History

• Obsolete Technology — Old Computers
• Historic Computers in Japan
• The History of Japanese Mechanical Calculating Machines
• Computer History — a collection of articles by Bob Bemer
• 25 Microchips that shook the world — a collection of articles by the Institute of Electrical and Electronics Engineers
• History of Computers and Calculators
• Rao/Scaruffi's History of Silicon Valley

Robert Metcalfe
Robert Metcalfe wearing the United States National Medal of Technology (2003).
Born	(1946-04-07) April 7, 1946 (age 66) Brooklyn, New York, United States.
Residence	United States
Citizenship	United States
Fields	Computer networking
Institutions	MIT, Xerox PARC, 3Com, The University of Texas at Austin.
Alma mater	MIT, Harvard University.
Doctoral advisor	Jeffrey P. Buzen
Known for	Co-invention of Ethernet.
Notable awards	National Medal of Technology, IEEE Medal of Honor, IEEE Alexander Graham Bell Medal, ACM Grace Murray Hopper Award, Computer History Museum Fellow Awards.

Robert Melancton Metcalfe (born April 7,^[1] 1946 in Brooklyn, New York) is an electrical engineer from the United States who co-invented Ethernet, founded 3Com and formulated Metcalfe's Law. As of January 2006^[update], he is a general partner of Polaris Venture Partners. Starting in January 2011, he holds the position of Professor of Electrical Engineering and Director of Innovation at The University of Texas at Austin.^[2]

Early life[link]

In 1964, Metcalfe graduated from Bay Shore Public High School. He graduated from MIT in 1969 with two B.S. degrees, one in Electrical Engineering and the other in Industrial Management from the MIT Sloan School of Management. He then went to Harvard for graduate school, earning his M.S. in 1970.

Career[link]

While pursuing a doctorate in computer science, Metcalfe took a job with MIT's Project MAC after Harvard refused to let him be responsible for connecting the school to the brand-new ARPAnet. At MIT's Project MAC, Metcalfe was responsible for building some of the hardware that would link MIT's minicomputers with the ARPAnet. Metcalfe was so enamored with ARPAnet, he made it the topic of his doctoral dissertation. However, Harvard flunked him. His inspiration for a new dissertation came while working at Xerox PARC where he read a paper about the ALOHA network at the University of Hawaii. He identified and fixed some of the bugs in the AlohaNet model and made his analysis part of a revised thesis, which finally earned him his Harvard PhD in 1973.^[3]

Metcalfe was working at Xerox PARC in 1973 when he and David Boggs invented Ethernet, a standard for connecting computers over short distances. Metcalfe identifies the day Ethernet was born as May 22, 1973, the day he circulated a memo titled "Alto Ethernet" which contained a rough schematic of how it would work. "That is the first time Ethernet appears as a word, as does the idea of using coax as ether, where the participating stations, like in AlohaNet or ARPAnet, would inject their packets of data, they'd travel around at megabits per second, there would be collisions, and retransmissions, and back-off," Metcalfe explained. Boggs identifies another date as the birth of Ethernet: November 11, 1973, the first day the system actually functioned.^[4]

In 1979, Metcalfe departed PARC and founded 3Com, a manufacturer of computer networking equipment. In 1980 he received the Association for Computing Machinery Grace Murray Hopper Award for his contributions to the development of local networks, specifically Ethernet. In 1990 Metcalfe lost a boardroom skirmish at 3Com in the contest to succeed Bill Krause as CEO. The board of directors chose Eric Benhamou to run the networking company Metcalfe had founded in his Palo Alto apartment in 1979. Metcalfe left 3Com and began a 10 year stint as a publisher and pundit, writing an Internet column for InfoWorld. He became a venture capitalist in 2001 and is now a General Partner at Polaris Venture Partners. He is a director of Pop!Tech, an executive technology conference he cofounded in 1997. He has recently been working with Polaris-funded startup Ember to work on a new type of energy grid, Enernet.

In November 2010 Metcalfe was selected to lead innovation initiatives at The University of Texas at Austin Cockrell School of Engineering. He began his appointment in January 2011.^[5]

Awards[link]

Metcalfe was awarded the IEEE Medal of Honor in 1996 for "exemplary and sustained leadership in the development, standardization, and commercialization of Ethernet."^[6]

Metcalfe received the National Medal of Technology from President Bush in a White House ceremony on March 14, 2003, "for leadership in the invention, standardization, and commercialization of Ethernet", having been selected for the honor in 2003.^[7] In May 2007, along with 17 others, Metcalfe, was inducted to the National Inventors Hall of Fame in Akron, Ohio, for his work with Ethernet technology.^[8]

In October 2008 Metcalfe received the Fellow Award from the Computer History Museum.^[9]

Incorrect predictions[link]

Outside of his technical achievements, Metcalfe is perhaps best known for his 1995 prediction that the internet would suffer a catastrophic collapse the following year; he promised to eat his words if it did not. During his keynote speech at the Sixth WWW International Conference in 1997, he took a printed copy of his column that predicted the collapse, put it in a blender with some liquid and then consumed the pulpy mass.^[10][11] This was after he tried to eat his words in the form of a very large cake, but the audience strongly protested.

During an event where he talked about predictions at the Eighth International World Wide Web Conference in 1999, a participant asked: what is the bet?. He stated that there was no bet as he was not ready to eat another column.

Metcalfe is also known for his harsh criticism of open source software, and Linux in particular, predicting that the latter would be obliterated after Microsoft released Windows 2000:

The Open Source Movement's ideology is utopian balderdash [... that] reminds me of communism. [...] Linux [is like] organic software grown in utopia by spiritualists [...] When they bring organic fruit to market, you pay extra for small apples with open sores – the Open Sores Movement. When [Windows 2000] gets here, goodbye Linux.^[12]

He later recanted to some extent, saying in a column two weeks later:

I am ashamed of myself for not resisting the temptation to take cheap shots in my column ... I should not have fanned the flames by joking about the Open Sores initiative.^[13]

He also predicted that wireless networking would die out in the mid 1990s.:

After the wireless mobile bubble bursts this year, we will get back to stringing fibers ... bathrooms are still predominantly plumbed. For more or less the same reason, computers will stay wired.^[14]

Selected publications[link]

• "Packet Communication", MIT Project MAC Technical Report MAC TR-114, December, 1973 (a recast version of Metcalfe's Harvard dissertation)
• "Zen and the Art of Selling", Technology Review, May/June 1992^[15]

See also[link]

• Metcalfe's Law

References[link]

External links[link]

Wikimedia Commons has media related to: Robert Metcalfe

• Robert Metcalfe on Twitter
• An interview with Robert Metcalfe
• Interview ITworld
• A more detailed interview
• Video - The History of Ethernet
• Why IT Matters
• Video Interview of Robert Metcalfe on March 10, 2009 at the Computer History Museum