Category: Timeline Stories

John Warner Backus (1924-2007), a bachelor of mathematics from Columbia University, saw his first computer in 1950, when he was hired as a programmer in the IBM Computer Center on Madison Avenue, to take care of the Selective Sequence Electronic Calculator (SSEC), an electromechanical computer (a hybrid of some 13000 vacuum tubes and 23000 electromechanical relays), built by IBM in January 1948. Wallace J. Eckert, the director of IBM’s Watson Scientific Computing Laboratory, did SSEC calculations of the moon’s orbit that would show up 20 years later in the Apollo space program.

Programming the SSEC was a real challenge, as there was no set way of doing it. Backus spent three years working on the SSEC, during which time he created a program called Speedcoding. The program was the first to include a scaling factor, which allowed both large and small numbers to be easily stored and manipulated.

In late 1953, Backus wrote a memo to his boss that outlined the design of a programming language for IBM’s new computer, the IBM 701, which, only the year before, had launched the company into a brand new world of electronic data processing. IBM approved Backus’ proposal, and in 1954 he was appointed as a boss of a small team of four people at the IBM Watson Scientific Laboratory. In May 1954 IBM launched a new computer, IBM 704 Data Processing System (an advanced computer with high-speed magnetic core memory, a magnetic drum storage unit, and a tape device, holding up to 5 million characters, see the below image), and the group switched to it.

IBM 704 had also a built-in scaling factor (automatic floating point operation), and index registers, which significantly reduced operating time. The inefficient computer programs of the time however would hamper the 704’s high performance, that’s why Backus wanted to design not only a better language but one that would be easier and faster for programmers to use when working with the machine. Backus wanted it to accept a concise formulation of a problem in terms of mathematical notation and to produce automatically a high-speed 704 program for its solution. Thus he decided to create a device that would translate the new language into something the machine could understand. This device, known as a translator, would eliminate the laborious hand-coding that characterized computer programming at the time. It contained an element known as a parser, which identified the various components of the program and translated them from a high-level language (one that people understand) into the binary language of the computer.

In November 1954, Backus and his team published the first formal proposal for the language—Preliminary Report, Specifications for the IBM Mathematical FORmula TRANslating System, FORTRAN. At the time, Backus anticipated completion of the compiler in six months. Instead, it would take almost three years, to be released commercially as late as 1957. FORTRAN appears to be the first high-level programming language to be put to broad use, after Konrad Zuse‘s Plankalkül, that (sadly) remained only on paper.

When completed, the Fortran compiler consisted of some 25000 lines of machine code, stored on a magnetic tape. A copy of the program was provided with every IBM 704 installation, along with a 54-page manual (see FORTRAN Programmer’s Reference Manual). The first versions of the program were understandably buggy, but later versions would refine and eliminate them.

The new language was designed preliminary for mathematicians and scientists and remains the preeminent programming language in these areas for more than three decades. It was the first widely used language, which allows people to work with their computers without having to understand how the machines actually work, and without having to learn the machine’s assembly language.

After Fortran, Backus turned his focus to other elements of computer programming. In 1959, in order to express the grammar of the new ALGOL language, he developed a notation (a formal way to describe formal languages) which will be called later the Backus-Naur Form. It describes grammatical rules for high-level languages and has been adapted for use in a number of languages. Backus-Naur Form quickly became the de facto worldwide standard for publishing algorithms. This contribution helped Backus win the Turing Award.

In the 1970s, Backus worked on finding better programming methods and developed what he called a function-level language, or FP (for functional programming).

Biography of John Backus

John Warner Backus was born in Philadelphia on 3 December 1924, to Cecil Franklin Backus (1885-1966) and Elizabeth Warner Edsall (1894-1933). Cecil Backus graduated with a degree in chemistry from the University of Virginia in 1906 and worked for the Eastern Laboratory of the Dupont De Nemours Powder Company before moving to work for the Atlas Powder Company in Wilmington, Delaware. He worked for the investment banking firm Gillespie & Meeds from 1920 to 1922. This firm became Laird, Bissell & Meeds and he was a partner from 1923 to 1940. Elizabeth Edsall, John’s mother, was the daughter of a Wilmington physician. Cecil and Elizabeth married on 28 May 1921 in Wilmington, New Castle, Delaware. They had three children, Anne Hall (born 25 March 1922), John Warner, and Cecil Franklin Jr. The family was well off and during the years that Cecil and Elizabeth Backus were married, they collected high-quality American antique furniture. After the early death of John’s mother Elizabeth in 1933, his father married Alice Beaver Candee (1901-1992) on 12 June 1935 in Wilmington, Delaware.

John spent his first years in Wilmington, Delaware, and then attended the Hill School in Pottstown, Pennsylvania. This family boarding school, founded in 1851, was highly regarded and run by the headmaster James Wendell. Backus graduated from the Hill School in 1942 although, according to his own account, he did not take his studies there too seriously.

John Backus entered the University of Virginia to study chemistry at his father’s request. In his first semester, he enjoyed the theory part of chemistry but disliked the laboratory work intensely. He enjoyed the social life, however, and was at every party that he could find. He was no more diligent than at school, however, and in his second semester, he only enrolled in one course – a music appreciation class. This was not what the University of Virginia expected of their students and in 1943 his studies were terminated. With America playing a major role in World War II, that year he joined the army. He was given the rank of corporal and put in charge of an antiaircraft crew at Fort Stewart, Georgia.

When he took this army aptitude test, his performance led to him being sent to the University of Pittsburgh to take the pre-engineering program. Given a medical aptitude test by the army, he was sent to Haverford College to take pre-medical training. Later in life, he thought that this may have saved his life since many of his friends at Pittsburgh were sent to Europe to serve on the Western Front. The Battle of the Bulge, the major German offensive in December 1944, saw the largest number of American casualties in the war, and many of Backus’s friends were killed. After a while at Haverford College, Backus was sent to an Atlantic City hospital where he worked in a neurosurgery ward that treated head wounds.

Strangely, a large bump on his head was noticed and he was found to have a bone tumor. After an operation to remove the tumor, he had a plate fitted in his head. For a while he was recovering, he had no duties and was able to enjoy the nightlife of Atlantic City. Again without any idea which direction he should take, he took an apartment in New York. The plate that had been put in his skull was giving problems so had a new one with the correct curvature fitted at a hospital on Staten Island. While in New York he met up with one of his friends from the University of Virginia. This friend took him to an apartment shared by three girls. One of the girls was Marjorie Ruth Jamison (30 September 1922—24 May 2010). Backus married Marjorie in 1947, and they had two daughters, Karen and Paula.

In 1945 Bakhus went to a radio technicians’ school, where he got interested in math. As a consequence, he entered Columbia University, New York, to study mathematics. He graduated with a B.S. in Mathematics in 1949 and continued to a Master’s Degree in 1950. Just before he graduated he visited the IBM Computer Center on Madison Avenue. When he told the guide that he was looking for a job she told him to talk to a director. There he took a test which he solved and was offered a job on the spot.

Backus joined IBM as a programmer in the Pure and Applied Science Departments in late 1950. The first problem he worked on was to write a program in machine code for the Selective Sequence Electronic Calculator (SSEC) to calculate the position of the moon from a function given by a series expansion with about 1000 terms. In 1954 he was appointed as manager of the Programming Research Department at IBM, a position he held for four years. He is considered the inventor of FORTRAN, the first high-level computer language to be developed. In 1959 he invented what is now called the Backus Naur Form (BNF), a standard notation to describe the syntax of a high-level programming language. (Peter Naur invented a similar scheme in 1960.) His third major contribution to computer science was to develop a functional programming language called FP, which advocates a mathematical approach to programming.

In 1966 Backus and his wife Marjorie were divorced. Just before they split up, Marjorie introduced Backus to Barbara Una Stannard (1927-2004) who was born Barbara Garlitz. Backus and Barbara, a poet and author with a Ph.D. from Harvard, were married on 18 July 1968 in San Francisco.

Backus received the President’s National Medal of Science from the National Science Foundation in 1975. For his pioneering contributions to computer programming languages, especially the development of the FORTRAN language which made the modern digital computer directly available to countless scientists and engineers. The Medal was presented by President Ford in a ceremony at the White House on 18 October 1976. He received the Turing Award from the Association for Computing Machinery in 1977.

John Backus died at his home in Ashland, Oregon, on 17 March 2007.

Rear Admiral Dr. Grace Murray Hopper (1906-1992) was a Ph.D. in mathematics, who devoted almost her entire life to computers and programming. She was one of the most incisive strategic futurists in the world of computing in the middle of the 20th century. Perhaps her best-known contribution to computing was the invention of the first compiler, the intermediate program that translates English language instructions into the language of the target computer.

Hopper started her career in computing in 1943, when she entered the Computation Project at Harvard University, to join the research team of Howard Aiken. Aiken, known to be rough-spoken, greeted her with the words, “Where the hell have you been?”, then pointed to his electromechanical Mark I computer, saying “Here, compute the coefficients of the arc tangent series by next Thursday.”

Hopper quickly plunged in and learned to program the machine, putting together a 500-page Manual of Operations for the Aiken’s computers in which she outlined the fundamental operating principles of computing machines. Later she joined the newly formed Eckert-Mauchly Corporation and remained associated with its successors (Remington-Rand, Sperry-Rand, and Univac) until her official retirement in 1971. There was a funny story from 1947 about Hopper finding the first computer “bug”: a dead moth that had gotten into the Mark I and whose wings were blocking the reading of the holes in the paper tape. In fact, the word “bug” had been used to describe a defect since at least 1889 but Hopper is credited with coining the word “debugging” to describe the work to eliminate program faults.

In 1952, Hopper completed her first compiler (for the Sperry-Rand computer), known as the A-0 System. As she said later, she did this, because she was lazy and hoped that the programmer may return to being a mathematician.

The A-0 System actually was a set of instructions that could translate symbolic mathematical code into machine language. In producing A-0, Hopper took all the subroutines she had been collecting over the years and put them on a tape. Each routine was given a call number so that the machine could find it on the tape. As described by Hopper—”All I had to do was to write down a set of call numbers, let the computer find them on the tape, bring them over and do the additions. This was the first compiler.”

After the A-0, Grace Hopper and her group produced versions A-1 and A-2, improvements over the older version. The A-2 compiler was the first compiler to be used extensively, paving the way for the development of programming languages.

The A-0 System was hardly accepted and dissuaded by the establishment, but Hopper followed her philosophy of “Go ahead and do it. You can apologize later.”. She was disappointed —”I had a running compiler, and nobody would touch it because, they carefully told me, computers could only do arithmetic; they could not do programs. It was a selling job to get people to try it. I think with any new idea because people are allergic to change, you have to get out and sell the idea.”

Hopper also originated the idea that computer programs could be written in English. She viewed letters as simply another kind of symbol that the computer could recognize and convert into machine code. Hopper’s compiler later evolved into the FLOW-MATIC compiler, which will be the base for the extremely important language—COBOL. FLOW-MATIC was aimed at business applications, such as calculating payroll and automatic billing. By the end of 1956, Hopper had UNIVAC I & II understanding of twenty English-like statements using FLOW-MATIC.

Biography of Grace Hopper

Grace Brewster Murray was born on 9 December 1906 in New York. She was the eldest of three children. Her parents, Walter Fletcher Murray (1873-1947) and Mary Campbell Van Horne (1883-1960) were of Scottish and Dutch descent and married in May 1903 in Manhattan. Walter Murray (Yale B.A. 1894, Phi Beta Kappa) was an insurance broker, as his father was before him. Mary Campbell was the daughter of the senior civil engineer of New York City, had always loved mathematics, and instilled this love in her first daughter. Grace had a sister, Mary Campbell (1909–2000), and a brother, Roger Franklin (1911–1998).

In an era when girls were expected to play house, Grace loved climbing trees, hiking, sailing, and reading. She also played basketball, hockey, and water polo, what a strange activity for girls?! She did have a dollhouse but was more interested in building toy furniture for it than in playing with dolls. She even built an elevator for it.

Grace’s parents encouraged her curiosity. They took her to museums, libraries, concerts, and lectures. Grace liked figuring out how things worked. When she was 7, she took apart her alarm clock. Gears and cogs flew out of the clock, but she couldn’t make sense of the mechanism. Instead of giving up, she dismantled all the other alarm clocks in the house, determined to discover how they worked.

Unfortunately, when Grace was 8, her father became ill and had to have both legs amputated. He never complained. His bravery inspired Grace to face challenges head-on. If her father could be so brave, Grace felt that she could conquer anything.

Grace’s father worried that he might not always be able to provide for his daughters. He wanted them to get a good education and be able to support themselves. He encouraged them to go to college and envision careers. Grace attended two private schools in New York: The Graham School and Miss Mary Schoonmaker’s School for Girls, then started at Vassar College, a private liberal arts college in Poughkeepsie when she was 17. She graduated from Vassar in 1928 with honors in physics and math and went on to study mathematics at Yale. Getting a master’s degree in 1930, then a Ph.D. in mathematics in 1934, the little girl who’d spent her days tinkering with clocks would become one of the greatest computer minds of her generation.

In 1930 Grace headed back to Vassar College to become a professor in math while also completing a Ph.D. at Yale. While attending Vassar College, Grace met Vincent Foster Hopper (1906–1976), a tall and handsome coeval, who was a professor of literature at New York University. They married in June 1930, but the family didn’t have children and in 1941 separated (finally divorcing in 1945). Although Grace never remarried, she retained his surname.

After the United States’ entry into World War II, Hopper decided to join the war effort. She was initially rejected because of her age and diminutive size (she was 16 pounds underweight for her height of five feet and six inches), but she persisted and eventually received a waiver to join the U.S. Naval Reserve (Women’s Reserve). In December 1943, she took a leave of absence from Vassar, where she was an associate professor, and completed sixty days of intensive training at the Midshipmen’s School for Women at Smith College in Northampton, Massachusetts. After receiving her commission (lieutenant junior grade), Hopper was assigned to the Bureau of Ships Computation Project at Harvard University, where began her long journey in the amazing world of computers.

Following a remarkable career that spanned more than 42 years, Rear Admiral Hopper, nicknamed “Amazing Grace” by her subordinates, took retirement from the Navy in August 1986. Following her retirement from the Navy, Hopper was hired as a senior consultant to Digital Equipment Corporation (DEC).

On New Year’s Day, 1 Jan 1992, Hopper died in her sleep of natural causes at her home in Arlington County, Virginia, at 85 years of age. She was interred with full military honors in Arlington National Cemetery.

The Computer Trainer Model 650 (named also CT-650), was developed at the beginning of 1967 by a man named Irving Becker (1917-2005), whose company produced a number of radios. CT-650 is considered to be one of the earliest digital personal computers, although it was not a personal computer, as we understand the term today, but rather a manually operated simulator. Some sources list this computer as the Arkay CT-650 because, like many who were involved with early computers, Irving Becker started off in radio and from 1945 was an owner of a company, that specialized in manufacturing of radio and hi-fi kits—Arkay (after Radio Kits) International Co., located in Hicksville, NY. By the time this computer was offered, however, Becker has already changed (in 1965) the name of the company from Arkay International Co. to Comspace Corporation of Farmingdale, N.Y. (Irving Becker was the president; his wife Helen Becker, was a secretary‐treasurer of the company, and their son Nelson was an employee, a genuine family business). 🙂

By the 1960’s Irving Becker was developing many educational products, including the digital computer CT-650 and a cardboard kit for Bell Laboratories, called CARDIAC (a reference to its cardboard construction and the names of other kits like the popular Simon, Brainiac, and Geniac of Edmund Berkeley). In fact, the CT-650 was designed by the chief engineer of Comspace—Frederick E. Barrett (1935-1983), who practically single-handedly engineered Comspace’s products.

Irving Becker was dedicated to education and even made a special version of the CT-650 that was made for blind students. Aside from Braille lettering, the bulbs under each light were extra strong so as to generate more heat, that way the student could “read” the results by feeling which lights were lit.

The CT-650 is sometimes called the paperclip computer, which is a reference to a very interesting 1967 book from Edward Alcosser, James P. Phillips, and Allen M. Wolk (see the nearby image), entitled How To Build A Working Digital Computer (see the book). The book describes how to make a simple digital computer out of things one might find around the house, such as tin cans (for drum memory), screws, paper clips (for switches), and even wooden spools of thread. The design of the CT-650 seems to have relied on the book’s plans and, therefore, it is called the paperclip computer. As a matter of fact, the authors of the book sued Becker and Comspace on that basis, but unsuccessfully, because the judge ruled that as the CT-650 was not a kit and not made of paperclips, etc. it did not infringe. Moreover, the book was published in June 1967, and Comspace was granted a copyright for a “General Operating Manual for Arkay CT-650 computer trainer” on 22 June 1967, so hardly Becker had enough time to read the book and then put together an operating manual.

The CT-650 computer (see the nearby image) is quite big—54″ in length by 22″ in depth. Due to its educational destination, it has six clearly labeled sections:
• Input Unit—accepts numerical inputs in decimal form and converts these to binary or binary-coded decimal (BSD) form
• Arithmetic Unit—performs binary arithmetic and processing functions as directed by the computer program
• Control Unit—interprets the programmed instructions and directs the sequence of operations for all computer units
• Output Unit—converts problem solutions from binary or BCD form to decimal form and displays them
• Core Memory—simulates a core memory, used in storing data while solving a problem
• Program Drum—performs as magnetic drum memory and is used to store the program. It was an aluminum cylinder with spring steel contactors that could read holes in a mylar sheet that represented various instructions in a program.

The CT-650 is easily programmed and has a versatile instruction set. The users may write their own programs, or order existing or new programs from a library, called the Arkay Program Library. A small number of CT-650 devices were sold (less than 100 were made), and the price was about $1000.

The funny thing is that the first “personal computer” in the world was (in fact) a calculator. It seems the earliest documented use of the term personal computer was in the 4 October 1968, issue of Science (Science is the academic journal of the American Association for the Advancement of Science and is considered one of the world’s most prestigious scientific journals). The issue contains a Hewlett-Packard ad for its new HP 9100A, saying: “The new Hewlett-Packard 9100A personal computer, is ready, willing, and able… to relieve you of waiting to get on the big computer… Ready to relieve you of waiting to get on the big computer… Willing to perform log and trig functions, even hyperbolics and coordinate transformations at the touch of a key. Able to take on roots of a fifth-degree polynomial, Bessel functions, elliptic integrals and regression analysis.

The development of the Hewlett-Packard 9100A started in 1965 in Palo Alto when a physicist named McMillian approached HP with a small calculator he invented. Tomas Osborne, another inventor, also approached HP with his own home-built calculator (when in 1971 the machine was patented (first application was filed in 1966), namely Osborne was specified as the inventor—see the US patent Nr. 3623156). The best features of the two products were combined, and Osborne was hired as a consultant to continue the development work in HP Labs.

In the early 1960s, as a graduate student in electrical engineering at the University of California at Berkeley (he earned an M.S.E.E. degree from Berkeley in 1962), Thomas E. Osborne began thinking about the design of a desktop electronic calculator suited for calculating the very large and very small numbers encountered in scientific work. In January 1964, he formed the firm Logic Design, Inc., to develop his ideas. By late 1964, he had built this prototype keyboard and display (see the nearby image), as well as a prototype logic unit (prototype overall measurements: 16.5 cm x 21.5 cm x 40 cm). In early 1965 Osborne demonstrated his calculator to several companies (like IBM and Monroe) in his apartment, where he’d built the machine, but without success, before being hired by Hewlett Packard in the spring of 1965 as a consultant with the responsibility for developing the architecture of the HP9100A.

The 9100A Desktop Computing Calculator (see the lower image) was introduced in March 1968. It was the first, totally self-contained programmable unit of its kind, which could fit on a desk (see the HP 9100A Brochure). It included a display with three registers and a magnetic card reader. An optional printer, which fit neatly on the top of the 9100A, was offered separately. The 9100A used a PC board ROM for its algorithms, including log and trig functions. Its volatile core memory used small ferrite rings through which were woven copper wires. The initial price of $4900 was rather steep, and it was later lowered to $4400. The 9100A was about the size and weight (18 kg) of a typewriter (see the Technical Description of HP 9100A) The device and the inventor have been presented in the September 1968 issue of HEWLETT-PACKARD Journal.

Programs and data were entered either through the 63-key keyboard or by means of wallet-sized magnetic cards capable of holding up to two complete read/write memory images. Data in the 9100A were represented as decimal floating-point numbers with two-digit exponents and twelve digits of mantissa precision. Results were displayed on a 5-in electrostatic CRT in three lines (numeric only), displaying the contents of three registers. Support was provided also for a full complement of arithmetic, logarithmic, exponential, trigonometric, hyperbolic, coordinate, memory, and programming functions. The speed of calculations was remarkable for the time—typical add/subtract operations completed in 2 ms, multiply required 22 ms, square-root 30 ms, and trigonometric functions 330 ms. Conditional and unconditional branching using flags and/or arithmetic comparisons were also provided, along with program halt, pause, and single-step execution.

The 9100A’s performance seems insignificant today with limited internal memory that stored only 196 steps. It was truly innovative for its time, however. It was organized into a 368-word by 6-bit read/write coincident current core memory for programs and data; a 64-word by 29-bit, 800 ns, threaded core ROM for control sequences; and a 512-word by 64-bit program ROM for microcode. The latter memory utilized a 16-layer printed circuit board with inductive coupling to sense lines from reference and address lines. This unusual technology achieved a density of 1000 bits per square inch using no integrated circuits!

A lot of peripheral devices can be connected to 9100A, let’s mention only:
• 9101A Extended Memory (adding 248 registers capable of storing 3472 additional program steps)
• 9104A Tape Reader (reads data into the 9100 from punched paper tape)
• 9107A Digitizer
• 9120A Printer
• 9125A X-Y Plotter
• 9150A Display Monitor (large Screen Display, with a 17-inch diagonal CRT (cathode ray tube) for use in classrooms or for displaying to any large group)
• 9160A Optical Card Reader (inputs program steps or data to the calculator using cards marked with a soft lead pencil)

Although the HP 9100A was really a desktop computer (but yet specialized for scientific and engineering purposes), the company decided to sell it as a calculator. At the time, the perception was that a computer had to be big to be accepted by the market. Calculators were also more likely to be bought than computers, she adds. Purchasing agents were authorized to buy calculators, whereas computers required top management participation, regardless of the cost. One of the company’s co-founders, Bill Hewlett, had another reason for marketing the 9100A as HP did:
“If we had called it a computer, it would have been rejected by our customer’s computer gurus because it didn’t look like an IBM. We, therefore, decided to call it a calculator and all such nonsense disappeared.”

Hewlett-Packard soon followed up with the 9100B, an enhanced version that provided several new features. In 1972 HP introduced the HP 9830A—the most powerful model of the original 9800 series calculators. It greatly blurred the lines between traditional computers and calculators due in part to its use of the BASIC programming language and options such as terminal emulation and a hard disk drive.

Alan Curtis Kay is an American computer scientist, known for his early pioneering work on computers, object-oriented programming, and windowing graphical user interface design. He was born on 17 May 1940, in Springfield, Massachusetts, and earned a Bachelor’s degree in Mathematics and Molecular Biology at the University of Colorado at Boulder. Before and during this time, he worked as a professional jazz guitarist.

In 1966, Kay began graduate school at the University of Utah College of Engineering, earning a Master’s degree and a Ph.D. degree in 1969. There, he worked with Ivan Sutherland, who had done pioneering graphics programs including Sketchpad. This greatly inspired Kay’s evolving views on objects and programming.

In 1967 Kay started his first attempt at designing a meta medium (the FLEX machine), focused on children as the future “user community.”

In 1968, Kay met mathematician and computer scientist Seymour Papert (1928-2016) and learned of the Logo programming language, a dialect of LISP optimized for educational use. Papert, a great influence on Kay, was creating computer systems for children to use creatively on the other side of the United States, at MIT. There, he developed LOGO. Kay’s previous work on FLEX had sought to create a computer that users could program themselves. This work led to the definition of object-oriented programming (inspired, in part, by Sutherland’s “Sketchpad”. From Papert’s work, Kay saw how far this idea could be carried, and refined his notion of why it was important. The next stage of Kay’s work in this area culminated in Smalltalk.

In 1970, Kay joined Xerox Corporation’s Palo Alto Research Center, PARC. In the 1970s he was one of the key members there to develop prototypes of networked workstations using the programming language Smalltalk. Kay was later a research fellow at Apple and then at Disney. Before these, and after his work at PARC, he directed Atari’s sizeable but short-lived research lab, which was the victim of the collapse of the U.S. videogame industry in the mid-1980s.

In 1968 Kay created a very interesting concept—the Dynabook. He wanted to make A Personal Computer For Children Of All Ages—a thin portable computer, a highly dynamic device that weighed no more than two pounds The ideas led to the development of the Xerox Alto prototype, which was originally called the interim Dynabook. It embodied all the elements of a graphical user interface, or GUI, as early as 1972. The software component of this research was Smalltalk, which went on to have a life of its own independent of the Dynabook concept.

The Dynabook concept described what is now known as a netbook computer or, (in some of its other incarnations) a tablet PC or slate computer with nearly eternal battery life and software aimed at giving children access to digital media. Adults could also use a Dynabook, but the target audience was children.

The Dynabook was never built, simply because it was too far ahead of technologies in the 1960s and 1970s. Kay and his group however continued to develop the concept. The first working prototype of Dynabook was built almost 20 years after creating the concept (see the nearby image). But it largely inspired not only the development of the first desktop personal and portable computers (e.g. Xerox NoteTaker drew heavily on Dynabook), graphical user interface, multimedia, as well as the devices we now call laptops, although it’s taken four decades to slim the tech down to the point where usable computers actually weigh is bellow 1 kg.

When later Kay accepted a position in Xerox’s PARC, he tried to interest Xerox execs in his project. His thoughts about an intimate personal computer were mostly of a service nature—that is, how could and should it act as an amplifier for human, especially child, endeavors? This is what led to quite a bit of UI, language, and media design, some of which made it out to the commercial world in the 1980s.

The concept of Dynabook is described in an August 1972 article by Kay A personal computer for children of all ages, presented at the ACM National Conference in Boston.

In the abovementioned paper is specified:
Although it (i.e. Dynabook) can be used to communicate with others through the “knowledge utilities” (or business information system), we think that a large fraction of its use will involve reflexive communication of the owner with himself through this personal medium, much as paper and notebooks are currently used…
What then is a personal computer? One would hope that it would be both medium for containing and expressing arbitrary symbolic notions, and also a collection of useful tools for manipulating these structures, with ways to add new tools to the repertoire… “Personal” also means owned by its user (needs to cost no more than a TV) and portable (which to me means that the user can easily carry the device and other things at the same time). Need we add that it be usable in the woods?
The size should be no larger than a notebook; weight less than 4 lbs.; the visual display should be able to present at least 400 printing quality characters with contrast ratios approaching that of a book; dynamic graphics of reasonable quality should be possible; there should be removable local file storage of at least one million characters traded off against several hours of audio files.
The active interface should be a language which uses linguistic concepts not far removed from the owner of the device. The owner will be able to maintain and edit his own files and programs when and where he chooses. He can use his Dynabook as a terminal when at work (or as a connection to the library system when in school). When he is done perusing and has discovered information that he wishes to abstract and take with him, it can rapidly be transferred to his local file storage…
A combination of this “carry anywhere” device and a global information utility such as ARPA network or two-way cable TV, will bring the libraries and schools (not to mention stores and billboards) of the world to the home. One can imagine one of the first programs an owner will write is a filter to eliminate advertising!

Sounds good, even for the 2020s, isn’t it?! Personal notebook computer with easy rechargeable battery and local drive memory, price some 500 USD, multimedia capabilities, wireless network access, Internet, etc. Let’s remind, this concept was created as early as the end of the 1960s and beginning of 1970s, when under “personal computer”, people recognize something like a DEC PDP-8 machine (see the nearby photo), wardrobe-size box, which cost 18000 USD, and didn’t have any of the abovementioned advanced features of Dynabook.

The work on advanced Laboratory INstrument Computer (LINC) was started in May 1961 by Wesley Clark and a team of engineers, led by Charles Molnar (Clark designed the logic, while Molnar did the engineering) at Lincoln Laboratory of MIT, Massachusetts, and the machine was eventually launched by Digital Equipment Corporation (DEC) in March 1962 (see the nearby photo). With its digital logic and stored programs, the LINC is accepted to be the first interactive personal computer in the world.

In 1961 Wesley Allison Clark (1927-2016), an electrical engineer at Lincoln Laboratory of MIT, who had contributed substantially to the development of the large TX-0 and TX-2 computers, ordered by the US Navy, realized that time sharing, used in these highly advanced machines, is not the only solution to the problem of direct access. He proposed building a relatively inexpensive, general-purpose computer that could be controlled easily by biomedical researchers.

Initially ignored by Lincoln Lab’s management, Clark continued to work on his idea for a small computer. He disappeared from the Lab for about three weeks at the end of 1961, and returned with a complete design for a small computer, with characteristics that marketing representatives would later call user-friendly.

Clark’s computer was designed to satisfy four basic criteria:
1. Easy to program
2. Easy to communicate with while in operation
3. Easy to maintain
4. To be able to process biotechnical signals directly.
No computer in the early 1960s could come close to fulfilling those objectives. Later, Clark added two shrewd criteria:
5. It could not be too high to see over, and
6. It must cost at most $25,000 (this was the amount a lab director could spend without higher-level approval).

LINC originally had one kilobit of core memory (1024 words), which was expanded to 2 Kb later. It was designed for interactive use via Graphical User Interface, with a 256 x 256 CRT display and four knobs (the equivalent of a mouse in those days) to enter variable parameters. The Soroban keyboard, for alpha-numeric entry, has keys that lockdown when pressed, and pop back up when the computer has read them, thereby solving the problem of type-ahead! Removable media was two LINC tape drives — the predecessor of DEC tape, each spool holds 512 blocks of 256 12-bit words, or 512 bytes—the characters (upper-case, plus various greek and math symbols) fit into 6 bits.

The standard program development software (an assembler and screen editor) of LINC—so-called Assembly Program (LAP), designed by Mary Allen Wilkes, was integrated with the Assembler and File System and was written for users, not computer professionals. LAP made it fairly easy to program LINC for biomedical experiments and, in its last version, was sufficiently flexible to allow for word processing.

A typical configuration of the machine (see the nearby image for one of the prototypes in MIT) included an enclosed 6’X20″ rack, four boxes holding tape drives, a small display, a control panel, and a keyboard. Analog inputs and outputs were part of the basic design. In these, the tall cabinet sitting behind a white-Formica-covered table held two somewhat smaller metal boxes holding the same instrumentation, a Tektronix display oscilloscope over the “front panel” on the user’s left, a bay for interfaces over two LINC-Tape drives on the user’s right, and a chunky keyboard between them.

Linc was manufactured commercially by DEC (starting in 1964) and Spear Inc. of Waltham, MA. The first LINC included two oscilloscope displays. Over the ensuing years, nearly a hundred LINCs were built for use in medical research before the design was absorbed into the DEC PDP-12. Twenty-one were sold by DEC at $43600 (a bargain at the time).

When a scientist sat down at the LINC keyboard, he had at his disposal a complete and comprehensible computer system. He could create a program and execute it in one sitting. Perhaps most elegantly, as the data were displayed an experiment could be tuned instantly by turning a knob hooked to an analog-to-digital converter. What sixth graders now take for granted was a remarkable achievement that led to a “computer pioneer” award to Wesley Clark—by the IEEE (Institute of Electrical and Electronic Engineers), which acknowledged Clark as the designer of the first personal computer, Eckert-Mauchly Award and membership to the National Academy of Engineering.

Wesley Clark had a small but key role in the planning for the ARPANET (the predecessor to the Internet). He suggested to Larry Roberts the idea of using separate small computers (later named Interface Message Processors) as a way of standardizing the network interface and reducing the load on the local computers.

Biography of Wesley Clark

Wesley Allison Clark Jr. was born in New Haven, Connecticut, on 10 April 1927, to Wesley Allison Clark Sr. (1897–1959) and Eleanor Southard Ella Kittell (1898–1982). He had a sister: Joan Murphy. Wesley Jr. grew up in Kinderhook, New York, and in northern California, where the family moved at the end of the 1920s. He attended the University of California, Berkeley, where he graduated with a degree in physics in 1947.

Clark became interested in computers while attending graduate school. In 1951, he began working in the computer lab at MIT where he learned programming and was involved in the Whirlwind project. Clark worked for MIT in various capacities three different times. “I’m probably the only person in the world fired three times by MIT for insubordination,” Clark used to say.

After leaving MIT for the final time, Clark worked at Washington University from 1964 to 1972. He has been a consultant since 1972 and was a co-founder of Clark, Rockoff, and Associates in Brooklyn, N.Y., with his wife, Maxine Lieberman Rockoff (born 1938). The family had four children—a daughter, Alison Eleanor, and three sons: Brian, Douglas Wells, and Peter. Clark’s oldest son, Douglas Wells, was a professor of computer science at Princeton University.

In 1981, Wesley Clark received the Eckert–Mauchly Award for his work on computer architecture. He was awarded an honorary degree by Washington University in 1984 and was elected to the National Academy of Engineering in 1999. Clark is a charter recipient of the IEEE Computer Society Computer Pioneer Award for “First Personal Computer”.

Wesley Clark died on 22 February 2016, at his home in Brooklyn due to severe atherosclerotic cardiovascular disease.

Edmund Callis Berkeley (1909–1988) was an American computer scientist, publisher, and social activist, who worked to achieve conditions that might minimize the threat of nuclear war. The first meeting of Berkeley with computers was in 1939 when he visited Bell Laboratories to see George Stibitz’s Complex Number Computer. Next was in 1942 when he joined the U. S. Navy and worked at Dahlgren Laboratory as a mathematician. There, he was assigned to Howard Aiken‘s Harvard Laboratory and observed Mark I, and worked on building on the next sequential calculator project (Mark II). In November 1946 he drafted a specification for Sequence Controlled Calculators for the Prudential, which led to signing a contract with the Eckert-Mauchly Computer Corporation in 1947 for one of the first UNIVAC computers.

In 1949, when Prudential forbade him to work on projects related to avoiding nuclear war, even on his own time, Edmund Berkeley left to become an independent consultant and found his own company—Berkeley Associates.

Shortly after the establishment of his company, in 1949, Edmund Berkeley wrote one of the first books on electronic computers for a general audience, which made him famous—Giant Brains, or Machines That Think (see the book). In the book, he described the principles behind computing machines (called then “electric brains”, “mechanical brains”, “sequence-controlled calculators”, or various other terms), and then gave a technical but accessible survey of the most prominent examples of the time, including machines from MIT, Harvard, the Moore School, Bell Laboratories, and elsewhere. Berkeley stated, that in the future “automated library” catalogue records (and, eventually, the documents) would be on microfilm and retrieved by a digital computer: “You will be able to dial into the catalogue machine ‘making biscuits.’ There will be a flutter of movie film in the machine. Soon it will stop, and, in front of you on the screen will be projected the part of the catalogue which shows the names of three or four books containing recipes for biscuits.”

In the above-mentioned book, Berkeley also outlined his own project, which seems to be the first personal computer in the world, called Simon—We shall now consider how we can design a very simple machine that will think. Let us call it Simon, because of its predecessor, Simple Simon… Simon is so simple and so small in fact that it could be built to fill up less space than a grocery-store box; about four cubic feet… It may seem that a simple model of a mechanical brain like Simon is of no great practical use. On the contrary, Simon has the same use in instruction as a set of simple chemical experiments has: to stimulate thinking and understanding, and to produce training and skill. A training course on mechanical brains could very well include the construction of a simple model mechanical brain, as an exercise.

Plans on how to build this computer, as well as a general description of the computer’s state of the art, were published in a series of 13 consecutive articles (see the first article, which is an introduction to Simon and relay logic) of the journal Radio Electronics, starting from October 1950 issue (see the nearby photo of the front cover of the journal).

Simon is a simple Harvard architecture machine, containing 129 relays (readily available at army surplus stores at that time), a stepping switch, and a five-hole paper tape feed. The program is executed directly from paper tape. Program instructions and data are input via a 5-level paper tape reader (5 bits or holes wide), as the 5-level paper tape was standard for use with teletypes before the advent of ASCII. Data may also be input manually via the front-panel switches during program execution.

Various registers are provided, some for general data storage, and others for targeted purposes. The registers and busses of Simon are a mixture of 2-bit and 4-bit wide. The processor (ALU) is also 2-bits wide.

Output is via the five lamps, connected to the Output Registers.

Operations performed by Simon included: addition, negation, greater than, selection, and several bitwise operations. To program Simon one has to prepare a paper tape with the machine instructions and data. The paper tape is the program memory: Simon executes the program instructions as it reads the tape, it does not load the program.

The tape reader reads in one direction only. All instructions on the tape are executed in sequence, there is no opportunity to skip instructions or branches. Some degree of conditional operation is provided for by the selective assignment function of the ALU. There is one opportunity to create a loop by forming the entire program tape into a loop.

A program may include programmed halts. Program execution stops, and the machine waits for manual indication before resuming execution. The output lamps can be observed at this point and/or a data value can be input from the front panel.

As an educational instrument, Simon was directed more towards the electrical implementation of logic and introducing the principles of binary arithmetic, logic, and automatic computation to a wider public, than towards programming. As such, and as a minimal machine, programmability is rather limited. The one saving grace may be that the program can be quite long (limited only by paper tape handling), a feature that certainly would not have been feasible in an attempt to make an inexpensive stored-program machine at the time.

Initially, Simon cost about $600 to construct. The first working model was built at Columbia University with the help of two graduate students. By 1959, over 400 Simon plans were sold.

What makes “Simon” unique? According to Edmund Berkeley, the machine has established at least half a dozen world records.
– It is the smallest complete mechanical brain in existence.
– It knows not more than four numbers; it can express only the numbers 0, 1, 2, and 3.
– It is “guaranteed to make every member of an audience feel superior to it.”
– It is a mechanical brain that has cost less than $1,000.
– It can be carried around in one hand (and the power supply in the other hand).
– It can be completely understood by one man.
– It is an excellent device for teaching, lecturing, and explaining.

Later Edmund Berkeley designed and sold several other simple calculating devices and robots like Squee (an electronic robot squirrel), Geniac (Genius Almost-Automatic Computer) (see the lower image), Tyniac (Tiny Almost-Automatic Computer), Weeniac (Weeny Almost-Automatic Computer), Brainiac (Brain-Imitating Almost-Automatic Computer), and Relay Moe (a tick-tack-toe machine with variable strategies).

The Squee robot was the featured construction project on the cover of the December 1951 issue of the journal Radio-Electronics (see the nearby image). It was an electronic robot squirrel, which had four sense organs (two photo-tubes, two contact switches), three acting organs (a drive motor, a steering motor, and a motor that opens and closes the scoop or “hands” in the front), and a small brain of half a dozen relays.

The primary goal of the Squee is to hunt for a “nut”. The “nut” is a tennis ball designated by a member of the audience who steadily holds a flashlight above the ball, pointing the light at Squee. Then Squee approaches, picks up the “nut” in its “hands” (the scoop), stops paying attention to the steady light, sees instead a light that goes on and off 120 times a second shining over its “nest”, takes the “nut” to its “nest”, then leaves the nuts, and then returns to hunting more “nuts”. When Squee is operating, it is a dramatic and exciting example of a robot. The machine however is sensitive to the surrounding light level, and usually has to be shown in a room about 8 by 10 ft. with only a small amount of overhead light and black curtained walls.

In 1956 Edmund Berkeley published an article (see Small Robots Report), summarizing his ideas, by presenting his small robot machines and also offering two electric brain construction kits.

As a whole, Edmund Berkeley’s books and computer/robot kits had a significant impact on the future of computer development (he wrote 16 books on computers and mathematics, and traveled the world lecturing on computers and the social responsibilities of computer scientists) and directly influenced many computer pioneers like Ivan Sutherland and Wesley Clark.

Biography of Edmund Berkeley

Edmund Callis Berkeley was born in Manhattan, New York, on 22 February 1909, to William Nathaniel Berkeley (1868-1928), a pathology doctor, and Clara Helene (Ellen) Berkeley. Besides Edmund, the family had one daughter: Ella Katherine.

Edmund’s primary school was St. Bernard’s School for Boys, an elite, private all-male elementary school in Manhattan, which he attended from 1918 to 1923. Then (from 1923 to 1925) he continued at Phillips Exeter Academy, a distinguished college preparatory school for boys in New Hampshire, where he was the youngest student, and graduated first in his class. There his teachers recognized his exceptional mathematical talent and directed him to individual instruction. At this time Edmund was already a very intelligent and socially awkward boy, who did not fit well with the sons of the elite families, who made the majority of students and were some 5-10 years older than him.

Edmund was only 16 when he graduated from Phillips Exeter Academy, so his parents decided to give him a break before college. For a year he lived in his family home near Columbia University, working as an instructor at St. Bernard’s School.

In 1926, Edmund entered Harvard College and graduated summa cum laude in Mathematics and Logic in June 1930. His dream from childhood was to become a mining engineer, but at Harvard he changed his mind, deciding on a career as a creative mathematician. For him, mathematics was not only rigorous reasoning, it was magic, the wizardry of Arabia. However, upon his graduation in 1930, the Great Depression was deepening, and his parents pressured him to be practical and to seek a career in business, instead of creative mathematics. That’s why after receiving his BA from Harvard, Edmund pursued a career as an actuarial clerk at Mutual Life Insurance of New York.

1934 was a happy year for Berkeley. In June he married Ruth Pirkle (1898-1991) of Cummings, Georgia, a 35 years old Ph.D. in biology and teacher at Hunter College in Manhattan. At the same time, he was happy to inherit over 8000 USD from his aunt. Thus the couple decided to go for three and half months honeymoon tour in Europe. They visited ten countries, including Italy, Greece, Turkey, Norway, and even Soviet Union.

Upon his return in the autumn of 1934, Berkeley took a position in the actuarial department of Prudential Insurance of America in New Jersey, where he eventually became chief research consultant. In 1937 he published an article in the magazine The Record of the American Institute of Actuaries, in which he argued for the use of symbolic logic for resolving insurance problems like analyzing risk and developing rules for writing policies.

During World War II Berkeley was given leave for military duty. In 1942 he was enlisted in the United States Navy as a Naval Reserve officer for three and a half years. Initially, he was an Inspector of supply, but later he was reassigned under Howard Aiken at the Harvard Computation Laboratory and was assigned to help run of Mark I computer. The work with Mark I was a really stimulating experience for Berkeley.

In 1946 Berkeley returned to his work at Prudential as a Senior Methods Analyst, later advancing to Chief Research Consultant. He was assigned a very interesting task—to determine how the company could use the new automatic electronic equipment for data processing. However, in 1948 a change in the company management resulted in an extensive reduction of his assignment, later he had other differences with them regarding the book, he was writing. Thus in 1948, he decided to go into his own business as a lecturer, consulting actuary, publisher, and developer of computers. His new-founded company, Berkeley Enterprises, was particularly interested in symbolic logic, computers, robots, mathematics, operations research, language, and explanation.

In 1949, Berkeley wrote one of the first books on electronic computers for a general audience, which made him famous—Giant Brains, or Machines That Think, in which he described the principles behind computers, and then gave a technical but accessible survey of the most prominent examples of the time, including machines from MIT, Harvard, the Moore School, Bell Laboratories, and others. In this book Berkeley envisioned that computers would be applied not only to mathematical and computational problems but also to a wide range of other problems, like finding information in a library, typing text from voice, translating languages, and controlling other machines.

Edmund and Ruth Berkeley divorced in 1948 (they had a daughter, Laura Helen), and in 1949 he married Susan Slocum Wallace (16 Aug. 1911—18 Feb. 2001) from Newtonville, Mass., adopting her three children to his family.

In the 1950s Berkeley devoted much effort to developing robots and made them available to anyone, who could pay a small sum for a mail ordered kit. In the October 1950 issue of the journal Radio Electronics was published an article, which was an introduction to Simon and relay logic. In the next issues were published 12 articles, dedicated to plans on how to build a computer, as well as a general description of the computers state of the art.

In 1950 Berkeley founded, published, and edited a journal, which was developed in 1951 to Computers and Automation, thought to be the first computer magazine.

Edmund Berkeley was a genius, whose eccentricities had become proverbial even before his talents were widely recognized. He died of liver cancer in Boston on 7 March 1988 and was buried in Newton Cemetery, Massachusetts. He was survived by his wife, Susan, two sons, a daughter, and a granddaughter.

Seymour Cray (1925–1996) is a legendary USA engineer and supercomputer architect who designed a series of computers, that were the fastest in the world for decades. Sometimes recognized as the Father of Supercomputing, Cray has been credited with creating the supercomputer industry. How does this story start?

After his 2-years service in the US Army during WWII, Seymour Cray, a native of Chippewa Falls, a small town in Wisconsin, returned to the United States in 1945 and enrolled at the University of Minnesota, where he graduated in 1949 with a Bachelor’s degree in Electrical Engineering, followed by a Masters degree in Applied Mathematics in 1951.

Still in the University, in 1950, Cray joined a new local company—Engineering Research Associates (ERA) in Saint Paul, Minnesota, which built specialized cryptographic equipment for the US Navy. While in ERA, he worked with a gamut of computer technologies, ranging from vacuum tubes and magnetic amplifiers to transistors. It was here that he quickly came to be regarded as an expert on digital computer technology, especially following his design work on the ERA 1103 (known as UNIVAC 1103)—the first commercially successful scientific computer (see the photo below).

ERA 1103 used electrostatic main storage (the first commercial computer to use RAM—random access memory), consisting of 36 Williams tubes (each was five inches in diameter) with a capacity of 1024 bits each, giving a total memory of 1024 words (36 bits each). It had a magnetic drum memory with 16384 words and a magnetic tape storage, four Raytheon or Potter units. The instruction set was 41 arithmetic and logical operations. The standard input and output equipment was a paper tape reader, a typewriter, and a paper tape punch, while optional can include a line printer, oscilloscope display unit, teletype, etc.

In 1958 Cray left ERA, to join the new Control Data Corporation (CDC), just established by his colleagues from ERA. By 1960 he had completed the design of the CDC 1604, an improved low-cost version of ERA 1103, that had an impressive performance for its price range. Then Cray designed the new CDC 6600, the first commercial supercomputer, outperforming everything then available by a wide margin. Although in terms of hardware, the 6600 was not truly advanced, Cray invested considerable effort into the design of the computer, in an attempt to enable it to run as fast as possible. Unlike most high-end projects of the time, Cray realized that there was considerably more to performance than simple processor speed and that I/O bandwidth had to be maximized as well in order to avoid “starving” the processor of data to crunch.

The CDC 6600 (see the nearby photo) was a large-scale, solid-state, general-purpose computing system. It had a distributed architecture (central scientific processor supported by ten very fast peripheral machines) and was a reduced instruction set (RISC) machine many years before such a term was invented. CDC 6600, announced in September 1964, was quite expensive for the time (base model price $2370000) and was the first computer designed in the new Chippewa Falls laboratory, in the hometown of Cray.

Input to the computer was by punch cards or digital magnetic tape, while output was two line printers, a card punch, a photographic plotter, and standard magnetic tape. Operator input was via a keyboard. An interactive display console allowed users to view graphical results as data were being processed. The computer had 65000 60-bit words of memory and was equipped with a large disk storage device and six high-speed drums as storage intermediate in speed and accessibility between the central core storage and magnetic tapes. The computer supported the FORTRAN 66 compiler and a program library. The still ubiquitous programming language Pascal was created on the CDC 6000 series computers at ETH Zurich.

After successful 6600, Cray worked on 2 other computers while in CDC—7600 and 8600. In 1972 he decided to left and establish his own company. Using the support of the CDC, as well as a group of former CDC employees, Cray founded Cray Research, using the same lab in Chippewa Falls and establishing a new production facility.

At first, it did not seem that there would be any way for Cray Research to afford to develop a new supercomputer, given that the now-large CDC had been unable to support more than one. But when Cray approached Wall Street to look for seed capital, he was surprised to find that his reputation was very well known. It seems the financial world was more than willing to provide Cray with all the money it would need to develop a new machine.

In 1975 the 80 MHz Cray-1 was announced, while the first box machine was delivered in 1976. Its theoretical performance was 160 MIPS (80 MHz x 2 instructions per cycle), although there were a few limitations that made floating point performance generally about 136 MFLOPS. Surprisingly, excitement was so high that something like a bidding war for the first system broke out between Lawrence Livermore National Laboratory and Los Alamos National Laboratory, the latter eventually winning and receiving serial number 1 in 1976 for a six-month trial. Cray-1 with serial number 3 went to the National Center for Atmospheric Research in 1977 (the machine was decommissioned in 1989), paying US$8.9 million ($7.9 million plus $1 million for the disks).

Cray Research expected to sell perhaps a dozen of the machines and set the selling price accordingly, but over eighty Cray-1s of all types were sold, priced from $5M to $8M. The machine made Cray a celebrity and the company a success, lasting until the supercomputer crash in the early 1990s.

When it was released it easily beat almost every machine in terms of speed, including the STAR-100 which had beaten the 8600 for funding. The only machine able to perform on the same sort of level was the ILLIAC IV, a specialized one-off machine that rarely operated near its maximum performance except on very specific tasks. In general, the Cray-1 beat anything on the market by a wide margin.

Designing the CDC supercomputers, Cray was able to look at the failure of the CDC STAR computer and learn from it. For Cray-1, he decided that in addition to fast vector processing, his design would also require excellent all-around scalar performance. That’s why Cray-1 has scalar and vector processing modes, that way when the machine switched modes, it would still be the fastest out there. Additionally, they noticed that the workloads could be dramatically improved in most cases through the use of registers. Cray implemented also his concept of chaining, as it allowed programmers to chain together several instructions and extract higher performance. Cray spent considerable time on the mechanical and electrical design of the system, improving performance through shortened cycle times.

The Cray-1 was a 64-bit system, with a 12.5 nanosecond clock period. Addressing was 24-bit, for a maximum of 1048576 72-bit words (64 data bits and 8 error correction bits) of main memory. Memory was spread across 16 banks, each with a 50 ns cycle time, allowing up to four words to be read per cycle. The main register set consisted of eight 64-bit scalar (S) registers and eight 24-bit address (A) registers, backed by a set of sixty-four registers each for S and A temporary storage known as T and B respectively, which could not be seen by the functional units.

The vector system was implemented by eight 64-element by 64-bit vector (V) registers. Integer and floating point arithmetic were supported. Twelve input and output channels are provided. A comprehensive description of Cray-1 can be seen in the Reference Manual.

Seymour Cray is universally known as the father of supercomputing because he was a builder of quite a few supercomputers:
• 1958 CDC 1604, an early “supercomputer”
• 1964 CDC 6600, the first supercomputer (1 MFLOP)
• 1969 CDC 7600 (RISC, 30 MFLOP)
• 1972 Cray-1 (vector processor, 160 MFLOP)
• 1982 Cray-XMP (parallel v-p, 800 MFLOP)
• 1985 Cray-2 (multi-CPU, 1.9 GFLOP)
• 1996 Cray 3 (GaAs, 16 GFLOP)

Biography of Seymour Cray

Seymour Roger Cray was born on 28 September 1925 in Chippewa Falls, a small town situated in the heart of Wisconsin’s dairy farm country, to Seymour Ruesink Cray (1900-1996), a civil engineer, and Lillian Grace Scholer Cray (1898-1992), a homemaker. After Seymour, the family had a daughter, Carol Jane Cray Kersten (1930–2009).

Seymour Cray Sr., the son of Seymour Romeo Cray (1866-1944) and Alice Eliza Beavington (1884-1967), was a good engineer who fostered his son’s interest in science and engineering. The basement of the family home was given over to the young Cray as a “laboratory”, to tinker with chemistry sets and radio gear. As early as the age of ten he was able to build a device out of Erector Set components that converted punched paper tape into Morse code signals.

Cray graduated from Chippewa Falls High School in 1943. While attending Chippewa Falls High School, Cray sometimes taught the physics class in his teacher’s absence. During his senior year, he received the Bausch & Lomb Science Award for meritorious achievement in science. Immediately after graduation, he was drafted for World War II as a radio operator. He saw action in Europe and then moved to the Pacific theatre where he worked on breaking Japanese naval codes. On his return to the United States, Cray earned a B.Sc. in electrical engineering at the University of Minnesota, graduating in 1949, followed by an M.Sc. in applied mathematics in 1951.

Cray began his career in 1950 at Engineering Research Associates (ERA), a leading digital computer company, to design computers for the Navy in a converted glider factory in St. Paul, Minn. While at ERA, he met John von Neumann. Company founder William Norris spotted Cray’s talents, and the young man blossomed under his mentoring. When in the mid-1950s ERA came under the control of the vast Sperry Rand Co., Norris and Cray set off on their own and formed Control Data Co. In 1976, Cray and Control Data parted ways when Norris, the company’s chief executive, placed a new computer on hold. Cray launched Cray Research Inc. and again set to work building supercomputers. In 1989, he started a new company, Cray Computer, but it went into bankruptcy in 1995.

Seymour Cray went down in history as one of the founding fathers of the computer industry. In 1972, he was awarded the Harry Goode Memorial Award for “outstanding achievement in the field of information processing.” The IEEE Computer Society’s Seymour Cray Computer Engineering Award, established in late 1997, recognizes innovative contributions to high-performance computing systems exemplifying Cray’s creative spirit.

Cray was not an ordinary man at all, even in the world of computer geniuses, where he belongs. His boss once asked him to develop a five-year plan. What he received in return was a short note that said Cray’s five-year plan was “to build the biggest computer in the world,” and his one-year plan was “to achieve one-fifth of the above.” And another time, when expected to write a multi-page detailed status report for the company executives, Cray’s two-sentence report read: “Activity is progressing satisfactorily as outlined under the June plan. There have been no significant changes or deviations from the June plan.” An avid sailor, Cray built a new sailboat each winter for several years. He also enjoyed skiing, windsurfing, tennis, and other sports. Another favorite pastime was digging a tunnel under his home; he attributed the secret of his success to “visits by elves” while he worked in the tunnel: “While I’m digging in the tunnel, the elves will often come to me with solutions to my problem.”

Cray married Verene Alice Voll (1926-2017) in 1947. They had known each other since childhood. She was the daughter of Obert Voll, a Methodist minister, just as was Cray’s mother, and Verene had a degree in home economics and nutrition. They had two daughters and a son—Susan Ruth (1949-), Stephen Ronald (1951-), and Carolyn Ann (1952-), but divorced in 1975. In 1980 Cray married Geri Martha Harrand (1936-).

The genius inventor Seymour Cray died in his Colorado Springs home, on 5 October 1996, two weeks after his automobile was struck on the highway and rolled several times, causing severe head and neck injuries.

After the famous PDP-1 in 1960, DEC established a successful business and during the middle 1960s launched its remarkable 12-bit PDP-8 series of minicomputers. During the late 1960s however, the time had come for the introduction of a 16-bit machine to replace the PDP-8. In 1967, one of DEC’s key design engineers, the 28 years old Edson de Castro was assigned to design a 16-bit machine, with the code name PDP-X. In the spring of 1968 however, the project was canceled and Ed de Castro and some of his friends went off to form another company, Data General, building the initial success of that company on his 16-bit NOVA computer. It seems however that the design by de Castro PDP-X has little relationship to DEC’s eventual 16-bit architecture, the PDP-11.

Gordon Bell, the vice president of research in DEC, was involved with recommending what became the PDP-11, while the actual design was made by Harold McFarland, who just graduated from the Electrical Engineering Department of Carnegie-Mellon University and was a protege of Gordon Bell, who was a professor at the University. McFarland had been working on several computer architectures while at University, and one of these architectures was essentially what became the PDP-11. McFarland joined DEC in September 1968 and was appointed chief architect of the project, the prototype of PDP-11 was ready in 1969, and in the spring of 1970, the computer was launched to the market.

The PDP-11 (Programmed Data Processor 11) was one the (if not the) most successful computers of all time. It began its career as a minicomputer and ended up as a micro or supermicro/supermini. It was manufactured from 1970 until the early 1990s. Members of its line were sold in very high numbers, more than 600000 computers were sold, thanks to the growing OEM industry. The VAX line of DEC began its life as an enhancement to the PDP-11 architecture, the first VAX computers are sometimes mentioned as PDP11-7xx, in contrast to the official label VAX-11/7xx.

The venerable PDP-11 is still spry to this day, powering a GE nuclear power-plant robotic applications — and will do so until 2050! That’s right!

The first model of PDP-11, (priced at 20000 USD), named PDP-11/20, was shipped in the spring of 1970. It had a word length of 16 bits, a speed of 800 nanoseconds, the cycle time was 1.5 microseconds, and the access time, 0.75 microseconds. The CPU had eight 16-bit registers, six general purposed, the stack pointer, and the program counter. Primary memory was magnetic core, 56 Kbytes (28 KWords) maximum (some documentation referred to 32k max memory, but the top 4k was reserved for the I/O space). Initial software included a symbolic editor, debugger, and utilities. PAL Architecture was UNIBUS. The console is TTY ASR33. The typical I/O was a paper-tape reader/punch.

PDP-11 was the first system to run an AT&T UNIX which was written in C. It was also the PDP-11 on which BSD UNIX was first developed.

One of the reasons, which made the PDP-11 so successful, was that it was designed to be produced in a factory by semiskilled labor. All of the dimensions of its pieces were relatively non-critical.

The PDP-11, like the PDP-8 before it, was cloned and copied extensively behind the so-called Iron Curtain, i.e. in Eastern European Socialist countries. A number of plants produced PDP-11 compatible systems in the Soviet Union (СМ-4, СМ-1420/xxx, СМ-1600/xxx, Електроника-xxx, etc.), Bulgaria (СМ-4, СМ-1420/xxx), DDR (SM-1420/xxx), Poland (Mera-xxx), Hungary (SM-4). Nobody knows how many of these clones were issued by many of the plants in the socialist countries, but some believe that the total amounts of units should be counted by tens of thousands.

Biography of Harold McFarland

Harold L. McFarland Jr. was born on 27 December 1945 in Portsmouth, Ohio, to Harold McFarland, Sr. (1922-1984) and Marilyn Frances Spence McFarland (1923-1984). In 1963 he enrolled at Carnegie Mellon University, where he graduated in 1968 with a degree in electrical engineering. McFarland worked for DEC from 1968 until the end of 1971, when he left to join Advanced Retail Systems (Litton). In 1979 McFarland became a member of the founding group (together with the electrical engineer Thampy Thomas) of Elxsi Corporation, a minicomputer manufacturing company established in Silicon Valley, USA. In 1986 McFarland and Thomas founded the semiconductor company NexGen Microsystems, best known for its unique implementation of the x86 architecture in its processors. McFarland worked for NexGen until his retirement in 1997. He was a holder of quite a few patents in the area of data processing and communications, e.g.: patent Nr. 3614741 (DATA PROCESSING SYSTEM) from 19 Oct. 1971, patent Nr. 4736124 (HIGH-SPEED DATABUS STRUCTURE) from 5 Apr. 1988, and patent Nr. 5414820 (CROSSING TRANSFERS FOR MAXIMIZING THE EFFECTIVE BANDWITH) from 9 May 1995, patent Nr. 5781753 (SEMI-AUTONOMOUS RISC PIPELINES) from 14 July 1998, and others.

Harold McFarland was married to Rita McFarland. They had three daughters: Sandi, Laurel, and Alana.

Harold L. “Mac” McFarland, who had a passion for knowledge and computer innovations throughout his life, passed away at age 72 on 14 July 2018 in Durham, North Carolina.

In 1959, a small and relatively new company (founded in 1957) for logic modules and other laboratory equipment, located in an old woolen mill in Maynard Massachusetts, named Digital Equipment Corporation (DEC), decided to build a computer. Ken Olsen, a cofounder of DEC, remembered: We had a dream of interactive computing. Normal computing was considered big, expensive, awesome, beyond ordinary people. Interactive computing was exciting and fun, and people could interact directly with the computer.

Announced in 1960 (the first machine was delivered in December 1959), DIGITAL’s landmark first computer, the PDP-1 (Programmed Data Processor-1), marked a radical shift in the philosophy of computer design: it was the first commercial computer that focused on interaction with the human user rather than the efficient use of computer cycles. Unlike the computers before it, it was centered around the user and actually it was the engineers, researchers, students, and hackers from a variety of companies and organizations, that brought DEC’s vision of the PDP-1 to life. The DEC people and the machine they created went on to have wide influence.

DEC management assigned the project to their best engineer and colleague from MIT, Ben Gurley. Benjamin Gurley (1926-1963) was a brilliant engineer and designer, who came to DEC from MIT’s Lincoln Laboratory, just like the founders of DEC—Ken and Stan Olsen brothers, and Harlan Anderson. While at MIT, Gurley worked on the TX-0 and TX-2 computers created at MIT in the second half of the 1950s (he designed the cathode ray tube display and light-pen of the TX-0), thus his computer design work at MIT greatly influenced the development of the PDP-1. The TX-0 and TX-2 computers, designed by Wesley Clark (the creator of the LINC computer), were (besides all) among the first transistor-driven computers in the world.

The work on PDP-1 began in the summer of 1959. Gurley formed a group to work on the computer with fellow engineers and former Lincoln Laboratory employees—Ken and Stan Olsen, Dick Best, Bob Savell, and Harlan Anderson. Amazingly, Gurley managed to build nearly the entire system himself in three-and-a-half months, making liberal use of DEC’s existing system building block product line—laboratory modules. He once joked that his assignment was “to make [the PDP-1] from inventory.” The truth, however, is that Gurley designed roughly half of the modules used in the PDP-1 from scratch.

The prototype was ready in November 1959, and the machine was featured in the November/December issue of the magazine Datamation (see the nearby image). The article outlining the many features of the new machine generated much advance interest in its appearance at Boston’s Eastern Joint Computer Conference.

The PDP-1 was a solid-state digital computer, built mostly of DEC 1000-series System Building Blocks, using Micro-Alloy and Micro-Alloy-Diffused transistors (it uses 2700 transistors and 3000 diodes) with a rated switching speed of 5 MHz. PDP-1 has an 18-bit word and 4 kilowords as standard main memory (equivalent to 9 kilobytes), upgradable to 64 kilowords (144 kB). The magnetic core memory’s cycle time was 5 microseconds, thus most arithmetic instructions took 10 microseconds (100000 operations per second) because they had two memory cycles: one for the instruction, and one for the operand data fetch.

PDP-1 was designed to operate with many types of input-output devices (among them typewriter, paper tape, cathode ray tube, light pen, magnetic tape, etc., see the list below) with no internal machine changes.

It is a single address, single instruction, stored program computer with powerful program features. It supports fully parallel processing and is unusually versatile. It is easy to install, operate and maintain. Conventional 110-volt power is used, neither air conditioning nor floor reinforcement is necessary, and preventive maintenance is provided for by built-in marginal checking circuits.

The PDP-1 used punched paper tape as its primary storage medium. Unlike punched card decks, which could be sorted and re-ordered, paper tape was difficult to physically edit. This inspired the creation of text-editing programs such as Expensive Typewriter and TECO.

The PDP-1 (see PDP-1 manual) was the first computer in Digital Equipment Corporation’s successful 14-members PDP series (The last model, PDP-16, was launched in 1972. The brilliant PDP-11 was produced up to 1996.). It is famous for being the computer most important in the creation of hacker culture at MIT, BBN, and elsewhere. The PDP-1 (with the optional high-resolution graphical display) was also the original hardware for playing history’s first game on a minicomputer, Steve Russell’s Spacewar!

Being the world’s first commercial interactive computer, the remarkable PDP-1 was used by its purchasers to pioneer timesharing systems, making it possible for smaller businesses and laboratories to have access to much more computing power than ever before.

The entire computer occupies below 2 sq. m. of floor space, dimensions of the system module are 1.5 x 2.5 x 1 m. PDP-1 consists of four equipment frames, one of which is used as the operating station.

CENTRAL PROCESSOR
The Central Processor contains the control, arithmetic, and memory addressing elements, and the memory buffer register. The word length is 18 binary digits. Instructions are performed in multiples of the memory cycle time of five microseconds. Add, subtract, deposit, and load, for example, are two-cycle instructions requiring 10 microseconds. Multiplication requires an average of 20 microseconds. Program features include single-address instructions, multiple-step indirect addressing, and logical arithmetic commands. Console features include flip-flop indicators grouped for convenient octal reading, six program flags for automatic setting and computer sensing, and six sense switches for manual setting and computer setting.

MEMORY SYSTEM
The coincident-current, magnetic core memory of a standard PDP-1 holds 4096 words of 18 bits each. The memory capacity may be readily expanded, in increments of 4096 words, to a maximum of 65536 words. The read-rewrite time of the memory is five microseconds, the basic computer rate. Driving currents are automatically adjusted to compensate for temperature variations between 50 and 110 degrees Fahrenheit. The core memory storage may be supplemented by up to 24 magnetic tape transports.

INPUT-OUTPUT
PDP-1 is designed to operate a variety of buffered input-output devices. Standard equipment consists of a perforated tape reader with a read speed of 400 lines per second, an alphanumeric typewriter for online operation in both input and output, and a perforated tape punch (alphanumeric or binary) with a speed of 63 lines per second. A variety of optional equipment is available, including the following:

• Precision CRT Display Type 30
• Ultra-Precision CRT Display Type 31
• Symbol Generator Type 33
• Light Pen Type 32
• Oscilloscope Display Type 34
• Card Punch Control Type 40-1
• Card Reader and Control Type 421
• Magnetic Tape Transport Type 50
• Programmed Magnetic Tape Control Type 51
• Automatic Magnetic Tape Control Type 52
• Automatic Magnetic Tape Control Type 510
• Parallel Drum Type 23
• Automatic Line Printer and Control Type 64
• 18-bit Real Time Clock
• 18-bit Output Relay Buffer Type 140
• Multiplexed A-D Converter Type 138/139

All in-out operations are performed through the In-Out Register or through the high-speed input-output channels.

The software included diagnostics routines, an assembler, a debugger, an editor, conversion routines for punching tapes, etc.

Despite its importance for the philosophy of computer design and its significant impact, the PDP-1 seems to be a commercial failure for DEC and was produced in relatively small quantities (53 machines, last built in 1969). The initial cost of a fully equipped system was $120000 ($85000 for minimal models), at a time when other computers sold for well over 1 million dollars.

Ben Gurley headed computer engineering in DEC until he left in 1962 to serve as vice president of Information International Inc., a consulting firm that created PDP-1 applications. His death in November 1963 at the hands of a deranged former colleague from DEC was a tragic loss to computer engineering (Gurley was murdered by a single rifle shot as he sat down to dinner with his wife and children at their home in Concord, Mass. The bullet entered the window and pierced his temple; he fell to the floor and died there in minutes, at the feet of his 5 children.)