Lee Felsenstein is an American computer engineer who played a central role in the development of the personal computer. He was one of the original members of the Homebrew Computer Club and the designer of the Osborne 1, the first mass-produced portable computer. Before the Osborne, Felsenstein designed the Intel 8080 based "SOL" computer from Processor Technology, the PennyWhistle modem, other early "S-100 bus" era designs, his shared-memory alphanumeric video display design, the Processor Technology VDM-1 video display module board, was copied and became the basis for the standard display architecture of personal computers. Many of his designs were leaders in reducing costs of computer technologies for the purpose of making them available to large markets, his work featured a concern for the social impact of technology and was influenced by the philosophy of Ivan Illich. Felsenstein was the engineer for the Community Memory project, one of the earliest attempts to place networked computer terminals in public places to facilitate social interactions among individuals, in the era before the commercial Internet.
In 2016, Lee was made a Fellow of the Computer History Museum. Felsenstein graduated from Central High School in Philadelphia as a member of class 219; as a young man, Felsenstein was a New Left radical. From October through December 1964, he was a participant in the Free Speech Movement and was one of 768 arrested in the climactic "Sproul Hall Sit-In" of December 2–3, 1964, he wrote for the Berkeley Barb, one of the leading underground newspapers. He had entered University of California, Berkeley first in 1963, joined the Co-operative Work-Study Program in Engineering in 1964 and dropped out at the end of 1967, working as a Junior Engineer at the Ampex Corporation from 1968 through 1971, when he re-enrolled at Berkeley, he received a B. S. in Electrical Engineering and Computer Science from the University of California, Berkeley in 1972. From 1981–1983, Felsenstein was employed at the Osborne Computer Corporation. At Osborne, he was the designer of the first mass-produced portable computer, he returned to freelance consulting.
In 1992, he joined Interval Research Corporation, where he worked until 2000 before joining Pemstar Pacific Consultants, where he worked until 2005. Throughout, he acted as an occasional free-lance consulting designer or worked at his own design firm. Many of his designs were leaders in reducing the costs of computer technologies for the purpose of making them available to large markets, his work featured a concern for the social impact of technology. The Community Memory project, begun as a project of Resource One, Inc. in 1972 and incorporated in 1977 by Felsenstein with Efrem Lipkin, Ken Colstad, Jude Milhon, Mark Szpakowski, was one of the earliest attempts to place networked computer terminals in such places as Berkeley supermarkets to attract casual use by persons from all walks of life passing through and facilitate social interactions among non-technical individuals, in the era before the Internet. Felsenstein was influenced in his philosophy by the works of Ivan Illich Tools for Conviviality.
This book advocated a "convivial" approach to design which allowed users of technologies to learn about the technology by encouraging exploration and modification. Felsenstein had learned about electronics in much the same fashion, summarized his conclusions in several aphorisms, to wit – "In order to survive in a public-access environment, a computer must grow a computer club around itself." Others were – "To change the rules, change the tools," and "If work is to become play tools must become toys." Felsenstein was one of the original members of the Homebrew Computer Club, which formed in 1975 in response to the appearance of the Altair 8800 computer kit. With a handy yardstick, Felsenstein "moderated" meetings at the SLAC Auditorium, he was less a chair than a keeper of chaos. In this heyday of the development of the first personal computers, Felsenstein designed the Intel 8080 based "SOL" computer from Processor Technology, the Pennywhistle modem, other early "S-100 bus" era designs; these existed in a market space with early generation hobbyist microcomputers from Altair, IMSAI, Morrow Designs and other vendors.
Felsenstein's shared-memory alphanumeric video display design, the Processor Technology VDM-1 video display module board, was copied and became the basis for the standard display architecture of personal computers. Felsenstein was named a "Pioneer of the Electronic Frontier" in 1994 by the Electronic Frontier Foundation, in 2007, he was given the Editor's Choice Award for Creative Excellence by EE Times magazine. In 1998, Felsenstein founded the Free Speech Movement Archives as an online repository of historical information relating to that event, its antecedents and successors. In 2003, while working with the Jhai Foundation of San Francisco, he designed an open-source telecommunications and computer system for installation in remote villages in the developing world; this system was dubbed "the Pedal-Powered Internet" by The New York Times Magazine due to its reliance on pedal power generation. Installation of the first system in Laos was unsuccessful, but the design has been tested on an Indian reservation in the US and continues in development in India.
In 2003, Felsenstein was named a Laureate of The Tech Museum of Innovation for this work. Felsenstein is the Founding Sensei of the Hacker Dojo in Mountain View and was featured on a Fox News segment in late 2009 covering the non-profit facility. Felsenstein's older brother is the evolutionary biologist Joseph Felsenstein, a National Academy of Sciences member whose PHYLIP system was one of the earliest examples
Motorola, Inc. was an American multinational telecommunications company founded on September 25, 1928, based in Schaumburg, Illinois. After having lost $4.3 billion from 2007 to 2009, the company was divided into two independent public companies, Motorola Mobility and Motorola Solutions on January 4, 2011. Motorola Solutions is considered to be the direct successor to Motorola, as the reorganization was structured with Motorola Mobility being spun off. Motorola Mobility was sold to Google in 2012, acquired by Lenovo in 2014. Motorola designed and sold wireless network equipment such as cellular transmission base stations and signal amplifiers. Motorola's home and broadcast network products included set-top boxes, digital video recorders, network equipment used to enable video broadcasting, computer telephony, high-definition television, its business and government customers consisted of wireless voice and broadband systems, public safety communications systems like Astro and Dimetra. These businesses are now part of Motorola Solutions.
Google sold Motorola Home to the Arris Group in December 2012 for US$2.35 billion. Motorola's wireless telephone handset division was a pioneer in cellular telephones. Known as the Personal Communication Sector prior to 2004, it pioneered the "mobile phone" with DynaTAC, "flip phone" with the MicroTAC, as well as the "clam phone" with the StarTAC in the mid-1990s, it had staged a resurgence by the mid-2000s with the Razr, but lost market share in the second half of that decade. It focused on smartphones using Google's open-source Android mobile operating system; the first phone to use the newest version of Google's open source OS, Android 2.0, was released on November 2, 2009 as the Motorola Droid. The handset division was spun off into the independent Motorola Mobility. On May 22, 2012, Google CEO Larry Page announced that Google had closed on its deal to acquire Motorola Mobility. On January 29, 2014, Page announced that, pending closure of the deal, Motorola Mobility would be acquired by Chinese technology company Lenovo for US$2.91 billion.
On October 30, 2014, Lenovo finalized its purchase of Motorola Mobility from Google. Motorola started in Chicago, Illinois, as Galvin Manufacturing Corporation in 1928 when brothers Paul V. and Joseph E. Galvin purchased the bankrupt Stewart Battery Company's battery-eliminator plans and manufacturing equipment at auction for $750. Galvin Manufacturing Corporation set up shop in a small section of a rented building; the company had $565 in five employees. The first week's payroll was $63; the company's first products were the battery eliminators, devices that enabled battery-powered radios to operate on household electricity. Due to advances in radio technology, battery-eliminators soon became obsolete. Paul Galvin learned that some radio technicians were installing sets in cars, challenged his engineers to design an inexpensive car radio that could be installed in most vehicles, his team was successful, Galvin was able to demonstrate a working model of the radio at the June 1930 Radio Manufacturers Association convention in Atlantic City, New Jersey.
He brought home enough orders to keep the company in business. Paul Galvin wanted a brand name for Galvin Manufacturing Corporation's new car radio, created the name “Motorola” by linking "motor" with "ola", a popular ending for many companies at the time, e.g. Moviola, Crayola; the company sold its first Motorola branded radio on June 23, 1930, to Herbert C. Wall of Fort Wayne, for $30. Wall went on to become one of the first Motorola distributors in the country; the Motorola brand name became so well known that Galvin Manufacturing Corporation changed its name to Motorola, Inc. Galvin Manufacturing Corporation began selling Motorola car-radio receivers to police departments and municipalities in November 1930; the company's first public safety customers included the Village of River Forest, Village of Bellwood Police Department, City of Evanston Police, Illinois State Highway Police, Cook County Police with a one-way radio communication. In the same year, the company built its research and development program with Dan Noble, a pioneer in FM radio and semiconductor technologies, who joined the company as director of research.
The company produced the hand-held AM SCR-536 radio during World War II, vital to Allied communication. Motorola ranked 94th among United States corporations in the value of World War II military production contracts. Motorola went public in 1943, became Motorola, Inc. in 1947. At that time Motorola's main business was selling televisions and radios. In October 1946 Motorola communications equipment carried the first calls on Illinois Bell telephone company's new car radiotelephone service in Chicago; the company began making televisions in 1947, with the model VT-71 with 7-inch cathode ray tube. In 1952, Motorola opened its first international subsidiary in Toronto, Canada to produce radios and televisions. In 1953, the company established the Motorola Foundation to support leading universities in the United States. In 1955, years after Motorola started its research and development laboratory in Phoenix, Arizona, to research new solid-state technology, Motorola introduced the world's first commercial high-power germanium-based transistor.
Byte was an American microcomputer magazine, influential in the late 1970s and throughout the 1980s because of its wide-ranging editorial coverage. Whereas many magazines were dedicated to specific systems or the home or business users' perspective, Byte covered developments in the entire field of "small computers and software," and sometimes other computing fields such as supercomputers and high-reliability computing. Coverage was in-depth with much technical detail, rather than user-oriented. Byte started in 1975, shortly after the first personal computers appeared as kits advertised in the back of electronics magazines. Byte was published monthly, with an initial yearly subscription price of $10. Print publication ceased in 1998 and online publication in 2013. In 1975 Wayne Green was the editor and publisher of 73 and his ex-wife, Virginia Londner Green was the Business Manager of 73 Inc. In the August 1975 issue of 73 magazine Wayne's editorial column started with this item: The response to computer-type articles in 73 has been so enthusiastic that we here in Peterborough got carried away.
On May 25th we made a deal with the publisher of a small computer hobby magazine to take over as editor of a new publication which would start in August... Byte. Carl Helmers published a series of six articles in 1974 that detailed the design and construction of his "Experimenter's Computer System", a personal computer based on the Intel 8008 microprocessor. In January 1975 this became the monthly ECS magazine with 400 subscribers; the last issue was published on May 12, 1975 and in June the subscribers were mailed a notice announcing Byte magazine. Carl wrote to another hobbyist newsletter, Micro-8 Computer User Group Newsletter, described his new job as editor of Byte magazine. I got a note in the mail about two weeks ago from Wayne Green, publisher of'73 Magazine' saying hello and why don't you come up and talk a bit; the net result of a follow up is the decision to create BYTE magazine using the facilities of Green Publishing Inc. I will end up with the editorial focus for the magazine. Virginia Londner Green had returned to 73 in the December 1974 issue and incorporated Green Publishing in March 1975.
The first five issues of Byte were published by Green Publishing and the name was changed to Byte Publications starting with the February 1976 issue. Carl Helmers was a co-owner of Byte Publications; the first four issues were produced in the offices of 73 and Wayne Green was listed as the publisher. One day in November 1975 Wayne came to work and found that the Byte magazine staff had moved out and taken the January issue with them; the February 1976 issue of Byte has a short story about the move. "After a start which reads like a romantic light opera with an episode or two reminiscent of the Keystone Cops, Byte magazine has moved into separate offices of its own." Wayne Green was not happy about losing Byte magazine so he was going to start a new one called Kilobyte. Byte trademarked KILOBYTE as a cartoon series in Byte magazine; the new magazine was called Kilobaud. There was competition and animosity between Byte Publications and 73 Inc. but both remained in the small town of Peterborough, New Hampshire.
Articles in the first issue included Which Microprocessor For You? by Hal Chamberlin, Write Your Own Assembler by Dan Fylstra and Serial Interface by Don Lancaster. Advertisements from Godbout, MITS, Processor Technology, SCELBI, Sphere appear, among others. Early articles in Byte were do-it-yourself electronic or software projects to improve small computers. A continuing feature was Ciarcia's Circuit Cellar, a column in which electronic engineer Steve Ciarcia described small projects to modify or attach to a computer. Significant articles in this period included the "Kansas City" standard for data storage on audio tape, insertion of disk drives into S-100 computers, publication of source code for various computer languages, coverage of the first microcomputer operating system, CP/M. Byte ran Microsoft's first advertisement, as "Micro-Soft", to sell a BASIC interpreter for 8080-based computers. In spring of 1979, owner/publisher Virginia Williamson sold Byte to McGraw-Hill, she became a vice president of McGraw-Hill Publications Company.
Shortly after the IBM PC was introduced, in 1981, the magazine changed editorial policies. It de-emphasized the do-it-yourself electronics and software articles, began running product reviews, it continued its wide-ranging coverage of hardware and software, but now it reported "what it does" and "how it works", not "how to do it". The editorial focus remained on home and personal computers). By the early 1980s Byte had become an "elite" magazine, seen as a peer of Rolling Stone and Playboy, others such as David Bunnell of PC Magazine aspired to emulate its reputation and success, it was the only computer publication on the 1981 Folio 400 list of largest magazines. Byte's 1982 average number of pages was 543, the number of paid advertising pages grew by more than 1,000 while most magazines' amount of advertising did not change, its circulation of 420,000 was the third highest of all computer magazines. Byte earned $9 million from revenue of $36.6 million in 1983, twice the average profit margin for the magazine industry.
It remained successful while many other magazines failed in 1984 during economic weakness in the computer industry. The October 1984 issue had about 300 pages of ads sold at an average of $6,000 per page. From 1975 to 1986 Byte covers featured the artwork of Robert Tinney. Thes
Cromemco's Dazzler was a graphics card for S-100 bus computers. Released in 1976, it is the first commercial color bit-mapped graphics card available for microcomputers. Multiple Dazzler cards could be installed in a single machine and synced together, a feature which could, with minor modification, be used to genlock. Genlocked Dazzler cards drove ColorGraphics Weather Systems displays that generated most of the weather imagery seen on US television in the early 1980s; the Dazzler came about in a roundabout fashion after Les Solomon, an editor for Popular Electronics magazine, demonstrated the original Altair 8800 to Roger Melen of Stanford University. After seeing it, Melen purchased Altair # 2 for his friend; the two built a number of add-ons for the machine, starting with an early video digitizer called the Cyclops and moving on to the prototype Dazzler. The Dazzler was first introduced at the Homebrew Computer Club on November 12, 1975. Like many early microcomputer projects of the era, the Dazzler was announced as a self-built kit in Popular Electronics.
In order to "kick start" construction, they offered kits including a circuit board and the required parts, which the user would assemble on their own. This led to sales of assembled Dazzler systems, which became the only way to purchase the product some time after. Sales were so fruitful that Melen and Garland formed Cromemco to sell the Dazzler and their other Altair add-ons, selecting a name based on Crothers Memorial Hall, their residence while attending Stanford; when Federico Faggin's new company - Zilog - introduced the Z80, Cromemco branched out into their own line of Z80-based S-100 compatible computers immediately. Over time these became the company's primary products. Combinations of their rackmount machines and the Dazzler formed the basis of ColorGraphics Weather Systems product line into the late 1980s, when CWS was purchased by Dynatech in 1987, Dynatech purchased Cromemco to supply them; the original advertisement for the Dazzler offered three different software programs for sale These were Conway's Game of Life, Dazzlewriter and a colorful pattern-generating program, Kaleidoscope.
The cover of the June 1976 issue of Byte magazine shows a Dazzler image from Conway's Game of Life, credits Ed Hall as author of the Life software for the Dazzler. Byte credits Steve Dompier with authoring the animation tool "Dazzlemation" and the first animation made with Dazzlemation called "Magenta Martini". George Tate is credited with a Tic-Tac-Toe game for the Dazzler, Li-Chen Wang is credited as the author of "Kaleidoscope". Stan Veit, owner of the Computer Mart of New York, described the reaction when he displayed the changing patterns of Kaleidoscope on a color television in his store window at the corner of 5th Avenue and 32nd Street in New York City in early 1976. “People driving by began to stop and look – they had never seen anything like it before. In a short time the Dazzler had caused a traffic jam on 5th Avenue!” The police had to make him disconnect the television. Over time, Cromemco introduced additional software for the Dazzler, at first on paper tape and floppy disk, including Spacewar! in October 1976.
Cromemco customers developed software for a wide range of graphics applications, from monitoring the manufacturing processes at a coffee factory in Columbia to displaying real-time images of heart blood flow, generated through cardiac radionuclide imaging, in Scotland. The Dazzler used over 70 MOS and TTL ICs, which required two cards to hold all the chips, "Board 1" held the analog circuits, while "Board 2" held the bus interface and digital logic; the two cards were connected together with a 16-conductor ribbon cable. Although the analog card did not talk on the bus, it would be plugged into the bus for power connections and physical support within the chassis; the manual described a way to "piggyback" the two cards with a separate power cable to save a slot. Output from the analog card was composite color, an RF modulator was available for direct connection to a color TV; the Dazzler lacked its own frame buffer, accessing the host machine's main memory using a custom DMA controller that provided 1 Mbit/s throughput.
The card read data from the computer at speeds that demanded the use of SRAM memory, as opposed to lower cost DRAMs. Control signals and setup was sent and received using the S-100 bus's input/output "ports" mapped to 0E and 0F. 0E contained an 8-bit address pointing to the base of the frame buffer in main memory, while 0F was a bit-mapped control register with various setup information. The Dazzler supported four graphics modes in total, selected by setting or clearing bits in the control register that controlled two orthogonal selections; the first selected the size of the frame buffer, either 512 bytes or 2 kB. The other selected normal or "X4" mode, the former using 4-bit nybbles packed 2 to a byte in the frame buffer to produce an 8-color image, or the latter, a higher resolution monochrome mode using 1-bits per pixel, 8 to a byte. Selecting the mode indirectly selected the resolution. In normal mode with a 512 byte buffer there would be 512 bytes × 2 pixels per byte = 1,024 pixels, arranged as a 32 by 32 pixel image.
A 2 kB buffer produced a 64 by 64 pixel image, while the highest resolution used a 2 kB buffer in X4 mode to produce a 128 by 128 pixel image. In normal mode the color was selected from a fixed 8-color palette with an additional bit selecting intensity, while in X4 mode the foreground color was selected by setting three bits in the control register to turn on red, green or blue while
Pirates of Silicon Valley
Pirates of Silicon Valley is an original 1999 American made for television biographical drama film, directed by Martyn Burke and starring Noah Wyle as Steve Jobs and Anthony Michael Hall as Bill Gates. Spanning the years 1971–1997 and based on Paul Freiberger and Michael Swaine's 1984 book Fire in the Valley: The Making of the Personal Computer, it explores the impact of the rivalry between Jobs and Gates on the development of the personal computer. Steve Jobs is speaking with director Ridley Scott, about the creation of the 1984 commercial for Apple Computer, which introduced the first Macintosh. Jobs is trying to convey his idea that "We're creating a new consciousness." Scott is more concerned with the technical aspects of the commercial. Next in 1997 with Jobs, returning to Apple, announcing a new deal with Microsoft at the 1997 Macworld Expo, his partner, Steve Wozniak or "WOZ", is introduced as one of the two central narrators of the story. Wozniak notes to the audience the resemblance between Big Brother and the image of Bill Gates on the screen behind Jobs during this announcement.
Asking how they "got from there to here," the film turns to flashbacks of his youth with Jobs, prior to the forming of Apple. The earliest flashback is in 1971 and takes place on the U. C. Berkeley campus during the period of the student anti-war movements. Teenagers Steve Jobs and Steve Wozniak are shown caught on the campus during a riot between students and police, they flee and after finding safety, Jobs states to Wozniak, "Those guys think they're revolutionaries. They're not revolutionaries, we are." Wozniak comments that "Steve was never like you or me. He always saw things differently; when I was in Berkeley, I would see something and just see kilobytes or circuit boards while he'd see karma or the meaning of the universe." Using a similar structure, the film next turns to a young Bill Gates at Harvard University, in the early 1970s, with classmate Steve Ballmer, Gates' high school friend Paul Allen. As with Wozniak in the earlier segment, Ballmer narrates Gates' story the moment when Gates discovers the existence of Ed Roberts's MITS Altair causing him to drop out of Harvard.
Gates' and Allen's early work with MITS is juxtaposed against the involvement of Jobs and Wozniak with the "Homebrew Computer Club". Jobs and Woz develop Apple Computer in the garage of Jobs' family home, with the help of Daniel and Elizabeth. Mike Markkula invests in the company which allows it to expand and move forward. In 1977, Jobs and Markkula demo the Apple II at the West Coast Computer Faire; this event is followed by the development of the IBM-PC with the help of Gates and Microsoft in 1981. The film follows Jobs' relationship with his high school girlfriend and early Apple employee and the difficulties he had acknowledging the birth and existence of their daughter, Lisa. Around the time his daughter was born, Jobs unveiled his next computer, The Lisa; the Lisa was followed in 1984 by the, a computer inspired by the Xerox Alto. The main body of the film concludes with a 30th birthday toast in 1985 to Steve Jobs shortly before he was fired by CEO John Sculley, from Apple Inc; the film ends in 1997, with 42 year old Jobs' return to Apple and with his announcement at the MacWorld Expo of an alliance between Apple and Microsoft.
It indicates that Jobs is now married, has children, has reconciled with Lisa. Noah Wyle as Steve Jobs Anthony Michael Hall as Bill Gates Joey Slotnick as Steve Wozniak John DiMaggio as Steve Ballmer Josh Hopkins as Paul Allen Gailard Sartain as Ed Roberts Jeffrey Nordling as Mike Markkula Allan Royal as John Sculley J. G. Hertzler as Ridley Scott Gema Zamprogna as "Arlene" Brooke Radding as Lisa Brennan-Jobs Marcus Giamatti as Daniel Kottke Melissa McBride as Elizabeth Holmes Burke notes that when he was shown the first draft of the screenplay, based upon Freiberger and Swaine's Fire in the Valley, "It was all about how the'286 computer' became the'386' and so on... I was bored by it." After the studio asked him for suggestions Burke states that "I'm a great believer in Shakespeare, what we had was a modern equivalent of Hamlet, featuring two young princes, Bill Gates and Steve Jobs... the more I read about Steve in particular, the more I saw him in those Shakespearean terms. He was brilliant, obsessive, suspicious vicious in a business sense.
He was about conquest, always conquest. I said,'That's the sort of movie I want to make." Burke rewrote the screenplay. In developing the characters themselves, Burke stated that he chose not to speak with any of the central figures portrayed in the film: I did not want to do an "authorized biography" on either Microsoft or Apple, so we made the decision going in that we would not talk or meet with them. With a team of Harvard researchers, I embarked on a seven-month research project that encompassed everything we could find on the history of both companies, including old technical magazines from the'70s. I intended every scene to be based on actual events, including such fantastic moments as Bill Gates' bulldozer races in the middle of the night and Steve Jobs' bare feet going up on the board room table during an applicant's job interview. I have two or more sources. Burke sought Noah Wyle for the part of Jobs. Wyle turned down the role, bu
Central processing unit
A central processing unit called a central processor or main processor, is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logic and input/output operations specified by the instructions. The computer industry has used the term "central processing unit" at least since the early 1960s. Traditionally, the term "CPU" refers to a processor, more to its processing unit and control unit, distinguishing these core elements of a computer from external components such as main memory and I/O circuitry; the form and implementation of CPUs have changed over the course of their history, but their fundamental operation remains unchanged. Principal components of a CPU include the arithmetic logic unit that performs arithmetic and logic operations, processor registers that supply operands to the ALU and store the results of ALU operations and a control unit that orchestrates the fetching and execution of instructions by directing the coordinated operations of the ALU, registers and other components.
Most modern CPUs are microprocessors, meaning they are contained on a single integrated circuit chip. An IC that contains a CPU may contain memory, peripheral interfaces, other components of a computer; some computers employ a multi-core processor, a single chip containing two or more CPUs called "cores". Array processors or vector processors have multiple processors that operate in parallel, with no unit considered central. There exists the concept of virtual CPUs which are an abstraction of dynamical aggregated computational resources. Early computers such as the ENIAC had to be physically rewired to perform different tasks, which caused these machines to be called "fixed-program computers". Since the term "CPU" is defined as a device for software execution, the earliest devices that could rightly be called CPUs came with the advent of the stored-program computer; the idea of a stored-program computer had been present in the design of J. Presper Eckert and John William Mauchly's ENIAC, but was omitted so that it could be finished sooner.
On June 30, 1945, before ENIAC was made, mathematician John von Neumann distributed the paper entitled First Draft of a Report on the EDVAC. It was the outline of a stored-program computer that would be completed in August 1949. EDVAC was designed to perform a certain number of instructions of various types; the programs written for EDVAC were to be stored in high-speed computer memory rather than specified by the physical wiring of the computer. This overcame a severe limitation of ENIAC, the considerable time and effort required to reconfigure the computer to perform a new task. With von Neumann's design, the program that EDVAC ran could be changed by changing the contents of the memory. EDVAC, was not the first stored-program computer. Early CPUs were custom designs used as part of a sometimes distinctive computer. However, this method of designing custom CPUs for a particular application has given way to the development of multi-purpose processors produced in large quantities; this standardization began in the era of discrete transistor mainframes and minicomputers and has accelerated with the popularization of the integrated circuit.
The IC has allowed complex CPUs to be designed and manufactured to tolerances on the order of nanometers. Both the miniaturization and standardization of CPUs have increased the presence of digital devices in modern life far beyond the limited application of dedicated computing machines. Modern microprocessors appear in electronic devices ranging from automobiles to cellphones, sometimes in toys. While von Neumann is most credited with the design of the stored-program computer because of his design of EDVAC, the design became known as the von Neumann architecture, others before him, such as Konrad Zuse, had suggested and implemented similar ideas; the so-called Harvard architecture of the Harvard Mark I, completed before EDVAC used a stored-program design using punched paper tape rather than electronic memory. The key difference between the von Neumann and Harvard architectures is that the latter separates the storage and treatment of CPU instructions and data, while the former uses the same memory space for both.
Most modern CPUs are von Neumann in design, but CPUs with the Harvard architecture are seen as well in embedded applications. Relays and vacuum tubes were used as switching elements; the overall speed of a system is dependent on the speed of the switches. Tube computers like EDVAC tended to average eight hours between failures, whereas relay computers like the Harvard Mark I failed rarely. In the end, tube-based CPUs became dominant because the significant speed advantages afforded outweighed the reliability problems. Most of these early synchronous CPUs ran at low clock rates compared to modern microelectronic designs. Clock signal frequencies ranging from 100 kHz to 4 MHz were common at this time, limited by the speed of the switching de
Ithaca Intersystems was a microcomputer manufacturer in the 1970s and 1980s, located in Ithaca, New York. The early years drew on engineering talent from Cornell University when the founders worked in a small rented space in the Collegtown neighborhood adjacent to the university campus, they produced the Ithaca Intersystems DPS-1 S-100 bus, Z80-based computer. As a large commercial success, the company moved to larger spaces outside of town, designed and produced a larger system, the Zilog Z8002-based DPS-8000; this used the Coherent Unix operating system from Mark Williams Company. The company languished in the 1980s, not being part of the domination of the IBM PC clones, they had an important role in the finalisation of the S-100 IEEE-696 Standard for S-100 and worked with Digicomp Research in Terrace Hill, who drew from Cornell Engineering. The Pascal-100 was supplied with an Ithaca S-100 box; the Pascal-100 was a dual processor Pascal MicroEngine front ended by a Z80: this board pair was designed built and supplied by Digicomp Research ) Marcus Bennett's InterSystems Datastore old-computer.com page on the DPS-1 Johnson Ithaca Audio page YouTube video of a working Ithaca InterSystems DPS-1