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City Technology College

In England, a City Technology College (CTC) is an urban all-ability specialist school for students aged 11 to 18 specialising in science, technology and mathematics. They charge no fees and are independent of local authority control, being overseen directly by the Department for Education. One fifth of the capital costs are met by private business sponsors, who also own or lease the buildings. The rest of the capital costs, and all running costs, are met by the Department.

Description
CTCs operate as limited companies with articles of association and a board of governors. A CTC is governed through an operating agreement made between the Secretary of State for Education and whoever is responsible for establishing and running the school. This agreement includes the regulations for the school's educational provision (e.g. its curriculum and admissions policy). These are negotiated between the two parties and must be enforced by the school should it wish to receive government funding from the Secretary of State. This funding covers most capital costs and all running costs, although one fifth of capital costs are instead met by private business sponsors, who also own or lease the buildings. More government funding is granted to be spent towards the school's pupils. This funding fluctuates on a per capita basis and depends on the size of the total pupil population.

CTCs teach the National Curriculum, but specialise in mainly technology-based subjects such as technology, science and mathematics. Like maintained schools, they are regularly inspected by the Office for Standards in Education. CTCs also forge close links with businesses and industry (mainly through their sponsors), and often their governors are directors of local or national businesses that are supporting or have supported the colleges. The programme has been successful in the long term with all the CTCs being considered strong establishments with consistently high academic results.

Development
Plans to establish schools or colleges for technology in major urban areas were first reported in an article from The Sunday Times in December 1985. There would be between sixteen and twenty of these institutions serving 1000 pupils each. They would charge no fees and would be publicly funded through an educational trust, but would select their pupils on a "special" basis. Unlike other state-funded schools at this time, these institutions would not be run by their local education authority (LEA or simply local authority). These plans were the brainchild of Schools Minister Bob Dunn, who had been pushing the Secretary of State for Education and Science Keith Joseph to introduce British magnet schools, with the ultimate aim of encouraging specialisation and increased parental choice in the education system. These schools, if introduced, would be known as technology-plus schools, specialist schools for technology with extra funding from private sector sponsors.

In January 1986, a Centre for Policy Studies meeting was held in the House of Lords. The meeting was organised by Cyril Taylor and focused on the growing issue of unemployment amongst the youth. Among the attendees were Prime Minister Margaret Thatcher, Secretary of State for Employment David Young, who chaired the meeting, and sixty other business leaders and politicians, twenty of whom were invited by Taylor. The twenty business leaders explained to Thatcher that the cause of youth unemployment was schools teaching the wrong skills to their pupils. They recommended, with Taylor, the creation of a hundred secondary schools similar to Bob Dunn's proposed technology-plus schools to deal with this issue. They would be urban inner city specialist schools for technological and technical education, funded by the central government via direct grant legislation and independent of local authority control, instead being partially controlled by private sector sponsors investing into them. Taylor thought that these schools could meet the growing demands for business qualifications in the workforce and also proposed a new provision for teacher training in these schools to combat the ongoing teacher shortage at the time.

A new Secretary of State for Education and Science, Kenneth Baker, was appointed on 21 May 1986. An advocate of technical education and technology in general, Baker was drawn towards the concept of schools for information technology, having formed this interest during his tenure as the Minister for Industry and Information Technology in the early 1980s. Computers were a rarity in schools at the time, so Baker set up an initiative to introduce a computer to every school in the country. Now in his position as Education Secretary, Baker wished to further improve digital learning and computing in the education system, and wanted to introduce schools for computing and information technology as a way to do so. In addition, schools for general technology were expected to give pupils the correct skills for employment, which supported the recommendations made some months prior by Cyril Taylor and his business leaders.

The policy for the schools proposed in January's meeting, dubbed City Technology Colleges or simply CTCs, was developed in the five months following Baker's appointment. This was influenced from talks surrounding other proposed technical schools, namely the technology-plus schools proposed by Bob Dunn, which occurred at the same time. Like CTCs, Dunn's technology-plus schools would be inner city specialist schools for technology with independence from their local authorities with some involvement from industry sponsors. Baker and Dunn worked together to develop the CTC policy, with the help of six other main individuals. They were Chris Patten, Cyril Taylor, George Walden, Virginia Bottomley, Alistair Burt and Tony Kerpel, all of whom served as ministers or advisers to Baker and his predecessor at the Department for Education and Science, Keith Joseph. The schools' independence from local authority control attracted Prime Minister Margaret Thatcher and her policy adviser Brian Griffiths, both of whom wanted local authorities phased out of the education system. Thatcher supported the policy on these grounds, alongside the belief that it would improve education and give schools increased autonomy from their local authorities.

Implementation
Finally, Baker announced the City Technology Colleges programme at the 1986 Conservative Party Conference, which had a goal of creating a national network of new CTCs that would boost educational diversity and parental choice in the school system, while also improving educational standards in their local areas. As expected, around twenty of these new schools were planned for creation in urban inner cities next to secondary schools already in operation, and all of them would have total independence from their LEA. They would serve pupils aged from eleven to eighteen, selecting them based on their "attitudes" towards a technological education. Despite this, the schools would not use an eleven-plus exam as was customary in other selective schools, and would be classified as comprehensive schools. They would specialise in science, technology and mathematics and have a strong provision for information technology and vocational education.

The first CTCs opened under the terms of the Education Reform Act 1988 in the late 1980s and early 1990s. The first City Technology College opened was The City Technology College, Kingshurst in 1988, which was later converted to an academy in 2008. The original intention was to improve education inside cities, but the programme was hampered by the refusal of local authorities in the targeted areas to provide suitable school sites. Building entirely new schools was much more expensive, requiring a greater contribution from the government, and the resulting schools tended to be on the outskirts of cities. After the programme was abandoned, the government embarked on the more modest aim of designating some existing schools as Technology Colleges, the first non-CTC specialist schools.

The Learning and Skills Act 2000 introduced a similar type of school, the City Academy, later renamed Academy. Differences from CTCs include halving the financial commitment of the sponsor, and being bound by the Schools Admissions Code. The Labour government encouraged CTCs to convert into academies.

Established
In all, 15 City Technology Colleges were created, of which all but three have converted to academies:

Proposed
Although there were only 15 City Technology Colleges by the end of the programme, there were a number of additional proposed CTCs that never opened:

title: City Technology College


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Grade (slope)

The grade (US) or gradient (UK) (also called stepth, slope, incline, mainfall, pitch or rise) of a physical feature, landform or constructed line refers to the tangent of the angle of that surface to the horizontal. It is a special case of the slope, where zero indicates horizontality. A larger number indicates higher or steeper degree of "tilt". Often slope is calculated as a ratio of "rise" to "run", or as a fraction ("rise over run") in which run is the horizontal distance (not the distance along the slope) and rise is the vertical distance.

Slopes of existing physical features such as canyons and hillsides, stream and river banks and beds are often described as grades, but typically the word "grade" is used for human-made surfaces such as roads, landscape grading, roof pitches, railroads, aqueducts, and pedestrian or bicycle routes. The grade may refer to the longitudinal slope or the perpendicular cross slope.

Nomenclature
There are several ways to express slope:
 * 1) as an angle of inclination to the horizontal. (This is the angle $α$ opposite the "rise" side of a triangle with a right angle between vertical rise and horizontal run.)
 * 2) as a percentage, the formula for which is $$ 100 \times \frac{\text{rise}}{\text{run}}$$ which is equivalent to the tangent of the angle of inclination times 100. In Europe and the U.S. percentage "grade" is the most commonly used figure for describing slopes.
 * 3) as a per mille figure (denoted with the symbol ‰), the formula for which is $$ 1000 \times \frac{\text{rise}}{\text{run}}$$ which could also be expressed as the tangent of the angle of inclination times 1000. This is commonly used in Europe to denote the incline of a railway.  It is sometimes written as mm/m or m/km instead of the ‰ symbol.
 * 4) as a ratio of one part rise to so many parts run. For example, a slope that has a rise of 5 feet for every 1000 feet of run would have a slope ratio of 1 in 200.  (The word "in" is normally used rather than the mathematical ratio notation of "1:200".) This is generally the method used to describe railway grades in Australia and the UK. It is used for roads in Hong Kong, and was used for roads in the UK until the 1970s.
 * 5) as a ratio of many parts run to one part rise, which is the inverse of the previous expression (depending on the country and the industry standards). For example, "slopes are expressed as ratios such as 4:1. This means that for every 4 units (feet or metres) of horizontal distance there is a 1 unit (foot or metre) vertical change either up or down."

Any of these may be used. Grade is usually expressed as a percentage, but this is easily converted to the angle $α$ by taking the inverse tangent of the standard mathematical slope, which is rise / run or the grade / 100. If one looks at red numbers on the chart specifying grade, one can see the quirkiness of using the grade to specify slope; the numbers go from 0 for flat, to 100% at 45 degrees, to infinity as it approaches vertical.

Slope may still be expressed when the horizontal run is not known: the rise can be divided by the hypotenuse (the slope length). This is not the usual way to specify slope; this nonstandard expression follows the sine function rather than the tangent function, so it calls a 45 degree slope a 71 percent grade instead of a 100 percent. But in practice the usual way to calculate slope is to measure the distance along the slope and the vertical rise, and calculate the horizontal run from that, in order to calculate the grade (100% × rise/run) or standard slope (rise/run). When the angle of inclination is small, using the slope length rather than the horizontal displacement (i.e., using the sine of the angle rather than the tangent) makes only an insignificant difference and can then be used as an approximation. Railway gradients are often expressed in terms of the rise in relation to the distance along the track as a practical measure. In cases where the difference between sin and tan is significant, the tangent is used. In either case, the following identity holds for all inclinations up to 90 degrees: $$\tan{\alpha} = \frac{\sin{\alpha}}{\sqrt{1-\sin^2{\alpha}}}$$. Or more simply, one can calculate the horizontal run by using the Pythagorean theorem, after which it is trivial to calculate the (standard math) slope or the grade (percentage).

In Europe, road gradients are signed as a percentage.

Equations
Grades are related using the following equations with symbols from the figure at top.

Tangent as a ratio

 * $$\tan{\alpha} = \frac{\Delta h}{d}$$

The slope expressed as a percentage can similarly be determined from the tangent of the angle:
 * $$\%\,\text{slope} = 100 \tan{\alpha}$$

Angle from a tangent gradient

 * $$\alpha = \arctan{\frac{\Delta h}{d}}$$

If the tangent is expressed as a percentage, the angle can be determined as:
 * $$\alpha = \arctan{\frac{\%\,\text{slope}}{100}}$$

If the angle is expressed as a ratio (1 in n) then:
 * $$\alpha = \arctan{\frac{1}{n}}$$

Example slopes comparing the notations
For degrees, percentage (%) and per-mille (‰) notations, larger numbers are steeper slopes. For ratios, larger numbers n of 1 in n are shallower, easier slopes.

The examples show round numbers in one or more of the notations and some documented and reasonably well known instances.

Roads
In vehicular engineering, various land-based designs (automobiles, sport utility vehicles, trucks, trains, etc.) are rated for their ability to ascend terrain. Trains typically rate much lower than automobiles. The highest grade a vehicle can ascend while maintaining a particular speed is sometimes termed that vehicle's "gradeability" (or, less often, "grade ability"). The lateral slopes of a highway geometry are sometimes called fills or cuts where these techniques have been used to create them.

In the United States, maximum grade for Federally funded highways is specified in a design table based on terrain and design speeds, with up to 6% generally allowed in mountainous areas and hilly urban areas with exceptions for up to 7% grades on mountainous roads with speed limits below 60 mph.

The steepest roads in the world according to the Guinness Book of World Records are Baldwin Street in Dunedin, New Zealand, Ffordd Pen Llech in Harlech, Wales and Canton Avenue in Pittsburgh, Pennsylvania. The Guinness World Record once again lists Baldwin Street as the steepest street in the world, with a 34.8% grade (1 in 2.87) after a successful appeal against the ruling that handed the title, briefly, to Ffordd Pen Llech.

A number of streets elsewhere have steeper grades than those listed in the Guinness Book. Drawing on the U.S. National Elevation Dataset, 7x7 (magazine) identified ten blocks of public streets in San Francisco open to vehicular traffic in the city with grades over 30 percent. The steepest at 41 percent is the block of Bradford Street above Tompkins Avenue in the Bernal Heights neighborhood. The San Francisco Municipal Railway operates bus service among the city's hills. The steepest grade for bus operations is 23.1% by the 67-Bernal Heights on Alabama Street between Ripley and Esmeralda Streets.

Likewise, the Pittsburgh Department of Engineering and Construction recorded a grade of 37% (20°) for Canton Avenue. The street has formed part of a bicycle race since 1983.

Environmental design
Grade, pitch, and slope are important components in landscape design, garden design, landscape architecture, and architecture; for engineering and aesthetic design factors. Drainage, slope stability, circulation of people and vehicles, complying with building codes, and design integration are all aspects of slope considerations in environmental design.

Railways
Ruling gradients limit the load that a locomotive can haul, including the weight of the locomotive itself. On a 1% gradient (1 in 100) a locomotive can pull half (or less) of the load that it can pull on level track. (A heavily loaded train rolling at 20 km/h on heavy rail may require ten times the pull on a 1% upgrade that it does on the level at that speed.)

Early railways in the United Kingdom were laid out with very gentle gradients, such as 0.07575% (1 in 1320) and 0.1515% (1 in 660) on the Great Western main line, nicknamed Brunel's Billiard Table, because the early locomotives (and their brakes) were feeble. Steep gradients were concentrated in short sections of lines where it was convenient to employ assistant engines or cable haulage, such as the 1.2 km section from Euston to Camden Town.

Extremely steep gradients require the use of cables (such as the Scenic Railway at Katoomba Scenic World, Australia, with a maximum grade of 122% (52°), claimed to be the world's steepest passenger-carrying funicular ) or some kind of rack railway (such as the Pilatus railway in Switzerland, with a maximum grade of 48% (26°), claimed to be the world's steepest rack railway ) to help the train ascend or descend.

Gradients can be expressed as an angle, as feet per mile, feet per chain, 1 in $n$, $x$% or $y$ per mille. Since designers like round figures, the method of expression can affect the gradients selected. The steepest railway lines that do not use a rack system include:
 * 13.5% (1 in 7.40) – Lisbon tram, Portugal
 * 11.6% (1 in 8.62) – Pöstlingbergbahn, Linz, Austria
 * 11.0% (1 in 9.09) – Cass Scenic Railway, US (former logging line)
 * 9.0% (1 in 11.11) – Ligne de Saint Gervais – Vallorcine, France
 * 9.0% (1 in 11.11) – Muni Metro J Church, San Francisco, US
 * 8.8% (1 in 11.4) – Iași tram, Romania
 * 8.65% (1 in 11.95) – Portland Streetcar, Oregon, US
 * 8.33%(1 in 12) – Nilgiri Mountain Railway Tamil Nadu, India
 * 8.0% (1 in 12.5) – Just outside the Tombstone Jct. Station in the Tombstone Junction Theme Park, Kentucky, US. The railroad line there had a ruling grade of 6% (1 in 16.7).
 * 7.85% (1 in 12.7) – Near Washington Street station on the Green Line B branch, Boston, Massachusetts, US.
 * 7.1% (1 in 14.08) – Erzberg Railway, Austria
 * 7.0% (1 in 14.28) – Bernina Railway, Switzerland
 * 6.0% (1 in 16.7) – Arica, Chile to La Paz, Bolivia
 * 6.0% (1 in 16.6) – Docklands Light Railway, London, UK
 * 6.0% (1 in 16.6) – Ferrovia Centrale Umbra, Italy
 * 6.0% (1 in 16.6) - Link Light Rail, Seattle, US
 * 5.89% (1 in 16.97) – Madison, Indiana, US
 * 5.6% (1 in 18) – Flåm Line, Norway
 * 5.3% (1 in 19) – Foxfield Railway, Staffordshire, UK
 * 5.1% (1 in 19.6) – Saluda Grade, North Carolina, US
 * 5.0% (1 in 20) – Khyber Pass Railway, Pakistan
 * 4.5% (1 in 22.2) – The Canadian Pacific Railway's Big Hill, British Columbia, Canada (prior to the construction of the Spiral Tunnels)
 * 4.0% (1 in 25) – Cologne-Frankfurt high-speed rail line, Germany
 * 4.0% (1 in 25) – Bolan Pass Railway, Pakistan
 * 4.0% (1 in 25) – (211.2 ft per 1 mi ) – Tarana – Oberon branch, New South Wales, Australia.
 * 4.0% (1 in 25) – Matheran Light Railway, India
 * 4.0% (1 in 26) – Rewanui Incline, New Zealand. Fitted with Fell center rail but was not used for motive power, but only braking
 * 3.6% (1 in 27) – Ecclesbourne Valley Railway, Heritage Line, Wirksworth, Derbyshire, UK
 * 3.6% (1 in 28) – The Westmere Bank, New Zealand has a ruling gradient of 1 in 35, however peaks at 1 in 28
 * 3.33% (1 in 30) – Umgeni Steam Railway, South Africa
 * 3.0% (1 in 33) – several sections of the Main Western line between Valley Heights and Katoomba in the Blue Mountains Australia.
 * 3.0% (1 in 33) – The entire Newmarket Line in central Auckland, New Zealand
 * 3.0% (1 in 33) – Otira Tunnel, New Zealand, which is equipped with extraction fans to reduce chance of overheating and low visibility
 * 3.0% (1 in 33) – The approaches to the George L. Anderson Memorial Bridge crossing the Neponset River, Boston, Massachusetts, US. The Ruling Gradient of the Braintree Branch of the Red Line (MBTA).
 * 2.7% (1 in 37) – Braganza Ghats, Bhor Ghat and Thull ghat sections in Indian Railways, India
 * 2.7% (1 in 37) – Exeter Central to Exeter St Davids, UK (see Exeter Central railway station)
 * 2.7% (1 in 37) – Picton- Elevation, New Zealand
 * 2.65% (1 in 37.7) – Lickey Incline, UK
 * 2.6% (1 in 38) – A slope near Halden on Østfold Line, Norway – Ok for passenger multiple units, but an obstacle for freight trains which must keep their weight down on this international mainline because of the slope. Freight traffic has mainly shifted to road.
 * 2.3% (1 in 43.5) – Schiefe Ebene, Germany
 * 2.2% (1 in 45.5) – The Canadian Pacific Railway's Big Hill, British Columbia, Canada (after the construction of the Spiral Tunnels)
 * 2.0% (1 in 48) – Beasdale Bank (West Coast Scotland mainline), UK
 * 2.0% (1 in 50) – Numerous locations on New Zealand's railway network, New Zealand
 * 1.51% (1 in 66) – (1 ft per 1 chain) New South Wales Government Railways, Australia, part of Main South line.
 * 1.25% (1 in 80) – Wellington Bank, Somerset, UK
 * 1.25% (1 in 80) – Rudgwick, UK (West Sussex) platform before regrading – too steep if a train is not provided with continuous brakes.
 * 0.77% (1 in 130) – Rudgwick, UK platform after regrading – not too steep if a train is not provided with continuous brakes.

Compensation for curvature
Gradients on sharp curves are effectively a bit steeper than the same gradient on straight track, so to compensate for this and make the ruling grade uniform throughout, the gradient on those sharp curves should be reduced slightly.

Continuous brakes
In the era before they were provided with continuous brakes, whether air brakes or vacuum brakes, steep gradients made it extremely difficult for trains to stop safely. In those days, for example, an inspector insisted that Rudgwick railway station in West Sussex be regraded. He would not allow it to open until the gradient through the platform was eased from 1 in 80 to 1 in 130.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Grade (slope)


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Kenneth E. Iverson

Kenneth Eugene Iverson (17 December 1920 – 19 October 2004) was a Canadian computer scientist noted for the development of the programming language APL. He was honored with the Turing Award in 1979 "for his pioneering effort in programming languages and mathematical notation resulting in what the computing field now knows as APL; for his contributions to the implementation of interactive systems, to educational uses of APL, and to programming language theory and practice".

Life
Ken Iverson was born on 17 December 1920 near Camrose, a town in central Alberta, Canada. His parents were farmers who came to Alberta from North Dakota; his ancestors came from Trondheim, Norway.

During World War II, he served first in the Canadian Army and then in the Royal Canadian Air Force. He received a B.A. degree from Queen's University and the M.Sc. and Ph.D. degrees from Harvard University. In his career, he worked for Harvard, IBM, I. P. Sharp Associates, and Jsoftware Inc. (née Iverson Software Inc.).

Iverson suffered a stroke while working at the computer on a new J lab on 16 October 2004, and died in Toronto on 19 October 2004 at age 83.

Education
Iverson began school on 1 April 1926 in a one-room school, initially in Grade 1, promoted to Grade 2 after 3 months and to Grade 4 by the end of June 1927. He left school after Grade 9 because it was the depths of the Great Depression and there was work to do on the family farm, and because he thought further schooling only led to becoming a schoolteacher and he had no desire to become one. At age 17, while still out of school, he enrolled in a correspondence course on radios with De Forest Training in Chicago, and learned calculus by self-study from a textbook. During World War II, while serving in the Royal Canadian Air Force, he took correspondence courses toward a high school diploma.

After the war, Iverson enrolled in Queen's University in Kingston, Ontario, taking advantage of government support for ex-servicemen and under threat from an Air Force buddy who said he would "beat his brains out if he did not grasp the opportunity". He graduated in 1950 as the top student with a Bachelor's degree in mathematics and physics.

Continuing his education at Harvard University, he began in the Department of Mathematics and received a Master's degree in 1951. He then switched to the Department of Engineering and Applied Physics, working with Howard Aiken and Wassily Leontief.

"Kenneth Iverson has recalled graduate study under Aiken as 'like an apprenticeship' in which the student 'learned the tools of the scholarship trade'. Every topic was 'used more as a focus for the development of skills such as clarity of thought and expression than as an end in itself'. Once admitted to the program, a graduate student underwent a rite of 'adoption into the fold'. He was given a desk (or a share of a desk) among a group of other graduate students, the permanent staff, or visiting scholars, 'most of whom were engaged in some aspect of the design and building of computers'. A student was thus 'made to feel part of a scholarly enterprise' and was provided, 'often for the first time, with easy and intimate access to others more experienced in his chosen field'."

"When interviewing Aiken, I had asked him whether Tropp and I might see his lecture notes; Aiken replied that he had always destroyed his lecture notes at the end of each year, so that he would not be tempted to repeat his lectures."

Howard Aiken had developed the Harvard Mark I, one of the first large-scale digital computers, while Wassily Leontief was an economist who was developing the input–output model of economic analysis, work for which he would later receive the Nobel prize. Leontief's model required large matrices and Iverson worked on programs that could evaluate these matrices on the Harvard Mark IV computer. Iverson received a Ph.D. in applied mathematics in 1954 with a dissertation based on this work.

At Harvard, Iverson met Eoin Whitney, a 2-time Putnam Fellow and fellow graduate student from Alberta. This had future ramifications.

Harvard (1955–1960)

Iverson stayed on at Harvard as an assistant professor to implement the world's first graduate program in "automatic data processing".

"Many people think that Aiken was interested only in scientific computers. This was simply not so. During one coffee hour, Aiken turned to Ken Iverson, who had just finished his Ph.D., and said: 'These machines are going to be immensely important for business, and I want you to prepare and teach a course in business data processing next fall.' There had never been such a course anywhere in the world. Ken was qualified only because he was a mathematician. I was so excited by the prospect that I immediately volunteered to be Ken's graduate teaching assistant."

It was in this period that Iverson developed notation for describing and analyzing various topics in data processing, for teaching classes, and for writing (with Brooks) Automatic Data Processing. He was "appalled" to find that conventional mathematical notation failed to fill his needs, and began work on extensions to the notation that were more suitable. In particular, he adopted the matrix algebra used in his thesis work, the systematic use of matrices and higher-dimensional arrays in tensor analysis, and operators in the sense of Heaviside in his treatment of Maxwell's equations, higher-order functions on function argument(s) with a function result. The notation was also field-tested in the business world in 1957 during a 6-month sabbatical spent at McKinsey & Company. The first published paper using the notation was The Description of Finite Sequential Processes, initially Report Number 23 to Bell Labs and later revised and presented at the Fourth London Symposium on Information Theory in August 1960.

Iverson stayed at Harvard for five years but failed to get tenure, because "[he hadn't] published anything but the one little book".

IBM (1960–1980)
Iverson joined IBM Research in 1960 (and doubled his salary). He was preceded to IBM by Fred Brooks, who advised him to "stick to whatever [he] really wanted to do, because management was so starved for ideas that anything not clearly crazy would find support." In particular, he was allowed to finish and publish A Programming Language and (with Brooks) Automatic Data Processing, two books that described and used the notation developed at Harvard. (Automatic Data Processing and A Programming Language began as one book "but the material grew in both magnitude and level until a separation proved wise". )

At IBM, Iverson soon met Adin Falkoff, and they worked together for the next twenty years. Chapter 2 of A Programming Language used Iverson's notation to describe the IBM 7090 computer. In early 1963 Falkoff, later joined by Iverson and Ed Sussenguth, proceeded to use the notation to produce a formal description of the IBM System/360 computer then under design. The result was published in 1964 in a double issue of the IBM Systems Journal, thereafter known as the "grey book" or "grey manual". The book was used in a course on computer systems design at the IBM Systems Research Institute. A consequence of the formal description was that it attracted the interest of bright young minds. One hotbed of interest was at Stanford University which included Larry Breed, Phil Abrams, Roger Moore, Charles Brenner, and Mike Jenkins, all of whom later made contributions to APL. Donald McIntyre, head of geology at Pomona College which had the first general customer installation of a 360 system, used the formal description to become more expert than the IBM systems engineer assigned to Pomona.

With the completion of the formal description Falkoff and Iverson turned their attention to implementation. This work was brought to rapid fruition in 1965 when Larry Breed and Phil Abrams joined the project. They produced a FORTRAN-based implementation on the 7090 called IVSYS (for Iverson system) by autumn 1965, first in batch mode and later, in early 1966, in time-shared interactive mode. Subsequently, Breed, Dick Lathwell (ex University of Alberta), and Roger Moore (of I. P. Sharp Associates) produced the System/360 implementation; the three received the Grace Murray Hopper Award in 1973 "for their work in the design and implementation of APL\360, setting new standards in simplicity, efficiency, reliability and response time for interactive systems." While the 360 implementation work was underway "Iverson notation" was renamed "APL", by Falkoff. The workspace "1 cleanspace" was saved at 1966-11-27 22.53.58 UTC. APL\360 service began within IBM several weeks before that and outside IBM in 1968. Additional information on the implementation of APL\360 can be found in the Acknowledgements of the APL\360 User's Manual and in "Appendix. Chronology of APL development" of The Design of APL.

The formal description and especially the implementation drove the evolution of the language, a process of consolidation and regularization in typography, linearization, syntax, and function definition described in APL\360 History, The Design of APL, and The Evolution of APL. Two treatises from this period, Conventions Governing the Order of Evaluation and Algebra as a Language, are apologias of APL notation.

The notation was used by Falkoff and Iverson to teach various topics at various universities and at the IBM Systems Research Institute. In 1964 Iverson used the notation in a one-semester course for seniors at the Fox Lane High School, and later in Swarthmore High School. After APL became available its first application was to teach formal methods in systems design at NASA Goddard. It was also used at the Hotchkiss School, Lower Canada College, Scotch Plains High School, Atlanta public schools, among others. In one school the students became so eager that they broke into the school after hours to get more APL computer time; in another the APL enthusiasts steered newbies to BASIC so as to maximize their own APL time.

In 1969, Iverson and the APL group inaugurated the IBM Philadelphia Scientific Center. In 1970 he was named IBM Fellow. He used the funding that came with being an IBM Fellow to bring in visiting teachers and professors from various fields, including Donald McIntyre from Pomona and Jeff Shallit as a summer student. For a period of several months the visitors would start using APL for expositions in their own fields, and the hope was that later they would continue their use of APL at their home institutions. Iverson's work at this time centered in several disciplines, including collaborative projects in circuit theory, genetics, geology, and calculus. When the PSC closed in 1974, some of the group transferred to California while others including Iverson remained in the East, later transferring back to IBM Research. He received the Turing Award in 1979.

The following table lists the publications which Iverson authored or co-authored while he was at IBM. They reflect the two main strands of his work.

 * Education
 * Automatic Data Processing
 * Elementary Functions: An Algorithmic Treatment
 * The Use of APL in Teaching
 * Using the Computer to Compute
 * Algebra: An Algorithmic Treatment
 * APL in Exposition
 * An Introduction to APL for Scientists and Engineers
 * Introducing APL to Teachers
 * Elementary Analysis
 * Programming Style in APL

 * Language design & implementation
 * A Programming Language
 * A Programming Language
 * A Common Language for Hardware, Software, and Applications
 * Programming Notation in System Design
 * Formalism in Programming Languages
 * A Method of Syntax Specification
 * A Formal Description of System/360
 * APL\360 User's Manual
 * Communication in APL Systems
 * The Design of APL
 * APL as an Analytic Notation
 * APLSV User's Manual
 * APL Language
 * Two Combinatoric Operators
 * The Evolution of APL
 * Operators and Functions
 * The Role of Operators in APL
 * The Derivative Operator
 * Operators
 * Notation as a Tool of Thought

I. P. Sharp Associates (1980–1987)

In 1980, Iverson left IBM for I. P. Sharp Associates, an APL time-sharing company. He was preceded there by his IBM colleagues Paul Berry, Joey Tuttle, Dick Lathwell, and Eugene McDonnell. At IPSA, the APL language and systems group was managed by Eric Iverson (Ken Iverson's son); Roger Moore, one of the APL\360 implementers, was a vice president.

Iverson worked to develop and extend APL on the lines presented in Operators and Functions. The language work gained impetus in 1981 when Arthur Whitney and Iverson produced a model of APL written in APL at the same time they were working on IPSA's OAG database. (Iverson introduced Arthur Whitney, son of Eoin Whitney, to APL when he was 11-years-old and in 1974 recommended him for a summer student position at IPSA Calgary. ) In the model, the APL syntax was driven by an 11-by-5 table. Whitney also invented the rank operator in the process. The language design was further simplified and extended in Rationalized APL in January 1983, multiple editions of A Dictionary of the APL Language between 1984 and 1987, and A Dictionary of APL in September 1987. Within IPSA, the phrase "dictionary APL" came into use to denote the APL specified by A Dictionary of APL, itself referred to as "the dictionary". In the dictionary, APL syntax is controlled by a 9-by-6 table and the parsing process was precisely and succinctly described in Table 2, and there is a primitive (monadic ⊥, modeled in APL) for word formation (lexing).

In the 1970s and 1980s, the main APL vendors were IBM, STSC, and IPSA, and all three were active in developing and extending the language. IBM had APL2, based on the work of Jim Brown. Work on APL2 proceeded intermittently for 15 years, with actual coding starting in 1971 and APL2 becoming available as an IUP (Installed User Program, an IBM product classification) in 1982. STSC had an experimental APL system called NARS, designed and implemented by Bob Smith. NARS and APL2 differed in fundamental respects from dictionary APL, and differed from each other.

I.P. Sharp implemented the new APL ideas in stages: complex numbers, enclosed (boxed) arrays, match, and composition operators in 1981, the determinant operator in 1982, and the rank operator, link, and the left and right identity functions in 1983. However, the domains of operators were still restricted to the primitive functions or subsets thereof. In 1986, IPSA developed SAX, SHARP APL/Unix, written in C and based on an implementation by STSC. The language was as specified in the dictionary with no restrictions on the domains of operators. An alpha version of SAX became available within I.P. Sharp around December 1986 or early 1987.

In education, Iverson developed A SHARP APL Minicourse used to teach IPSA clients in the use of APL, and Applied Mathematics for Programmers and Mathematics and Programming which were used in computer science courses at T.H. Twente.

Publications which Iverson authored or co-authored while he was at I. P. Sharp Associates:

 * Education
 * The Inductive Method of Introducing APL
 * A SHARP APL Minicourse
 * Applied Mathematics for Programmers
 * Mathematics and Programming

 * Language design & implementation
 * Operators and Enclosed Arrays
 * Direct Definition
 * Composition and Enclosure
 * A Function Definition Operator
 * Determinant-Like Functions Produced by the Dot-Operator
 * Practical Uses of a Model of APL
 * Rationalized APL
 * APL Syntax and Semantics
 * Language Extensions of May 1983
 * An Operator Calculus
 * APL87
 * A Dictionary of APL
 * Processing Natural Language: Syntactic and Semantic Mechanisms

Jsoftware (1990–2004)

Iverson retired from I. P. Sharp Associates in 1987. He kept busy while "between jobs". Regarding language design, the most significant of his activities in this period was the invention of "fork" in 1988. For years, he had struggled to find a way to write f+g as in calculus, from the "scalar operators" in 1978, through the "til" operator in 1982, the catenation and reshape operators in 1984, the union and intersection operators in 1987, "yoke" in 1988, and finally forks in 1988. Forks are defined as follows:

Moreover, (f g p q r) ←→ (f g (p q r)). Thus to write f+g as in calculus, one can write f+g in APL. Iverson and Eugene McDonnell worked out the details on the long plane rides to the APL88 conference in Sydney, Australia, with Iverson coming up with the initial idea on waking up from a nap.

Iverson presented the rationale for his work post 1987 as follows:

"When I retired from paid employment, I turned my attention back to this matter [the use of APL for teaching] and soon concluded that the essential tool required was a dialect of APL that:
 * • Is available as 'shareware', and is inexpensive enough to be acquired by students as well as by schools
 * • Can be printed on standard printers
 * • Runs on a wide variety of computers
 * • Provides the simplicity and the generality of the latest thinking in APL

The result has been J, first reported in [the APL 90 Conference Proceedings]."

Roger Hui described the final impetus that got J started in Appendix A of An Implementation of J:

"One summer weekend in 1989, Arthur Whitney visited Ken Iverson at Kiln Farm and produced—on one page and in one afternoon—an interpreter fragment on the AT&T 3B1 computer. I studied this interpreter for about a week for its organization and programming style; and on Sunday, August 27, 1989, at about four o'clock in the afternoon, wrote the first line of code that became the implementation described in this document.

Arthur's one-page interpreter fragment is as follows: ..."

Hui, a classmate of Whitney at the University of Alberta, had studied A Dictionary of the APL Language when he was between jobs, modelled the parsing process in at least two different ways, and investigated uses of dictionary APL in diverse applications. As well, from January 1987 to August 1989 he had access to SAX, and in the later part of that period used it on a daily basis.

J initially took A Dictionary of APL as the specification, and the J interpreter was built around Table 2 of the dictionary. The C data and program structures were designed so that the parse table in C corresponded directly to the parse table in the dictionary. In retrospect, Iverson's APL87 paper APL87, in five pages, prescribed all the essential steps in writing an APL interpreter, in particular the sections on word formation and parsing. Arthur Whitney, in addition to the "one-page thing", contributed to J development by suggesting that primitives be oriented on the leading axis, that agreement (a generalization of scalar extension) should be prefix instead of suffix, and that a total array ordering be defined.

One of the objectives was to implement fork. This turned out to be rather straightforward, by the inclusion of one additional row in the parse table. The choice to implement forks was fortuitous and fortunate. It was realized only later that forks made tacit expressions (operator expressions) complete in the following sense: any sentence involving one or two arguments that did not use its arguments as an operand, can be written tacitly with fork, compose, the left and right identity functions, and constant functions.

Two obvious differences between J and other APL dialects are: (a) its use of terms from natural languages instead of from mathematics or computer science (the practice began with A Dictionary of APL): noun, verb, adverbs, alphabet, word formation, sentence, ... instead of array, function, operator, character set, lexing, expression, ... ; and (b) its use of 7-bit ASCII characters instead of special symbols. Other differences between J and APL are described in J for the APL Programmer and APL and J.

The J source code is available from Jsoftware under the GNU General Public License version 3 (GPL3), or a commercial alternative.

Eric Iverson founded Iverson Software Inc., in February 1990 to provide an improved SHARP APL/PC product. It quickly became obvious that there were shared interests and goals, and in May 1990 Iverson and Hui joined Iverson Software Inc.; later joined by Chris Burke. The company soon became J only. The name was changed to Jsoftware Inc., in April 2000.

Publications which Iverson authored or co-authored while he was at Iverson Software Inc. and Jsoftware Inc.:

 * Education
 * Tangible Math
 * Programming in J
 * Arithmetic
 * Calculus
 * Concrete Math Companion
 * Exploring Math
 * J Phrases
 * ICFP '98 Contest Winners
 * Math for the Layman

 * Language design & implementation
 * A Commentary on APL Development
 * Phrasal Forms
 * APL/?
 * Tacit Definition
 * A Personal View of APL
 * J Introduction and Dictionary
 * Revisiting Rough Spots
 * Computers and Mathematical Notation
 * Mathematical Roots of J
 * APL in the New Millennium

Awards and honors

 * IBM Fellow, IBM, 1970
 * Harry H. Goode Memorial Award, IEEE Computer Society, 1975
 * Member, National Academy of Engineering (USA), 1979
 * Turing Award, Association for Computing Machinery, 1979
 * Computer Pioneer Award (Charter recipient), IEEE Computer Society, 1982
 * Honorary doctorate, York University, 1998
 * In 2015, a new moth species, Agdistis iversoni, was named after him.

title: Kenneth E. Iverson


text:
TRW Inc.

TRW Inc., was an American corporation involved in a variety of businesses, mainly aerospace, electronics, automotive, and credit reporting. It was a pioneer in multiple fields including electronic components, integrated circuits, computers, software and systems engineering. TRW built many spacecraft, including Pioneer 1, Pioneer 10, and several space-based observatories. It was #57 on the 1986 Fortune 500 list, and had 122,258 employees. The company was called Thompson Ramo Wooldridge Inc., after the 1958 merger of the Ramo-Wooldridge Corporation and Thompson Products. This was later shortened to TRW.

The company was founded in 1901 and lasted for just over a century until being acquired by Northrop Grumman in 2002. It spawned a variety of corporations, including Pacific Semiconductors, The Aerospace Corporation, Bunker-Ramo and Experian. Its automotive businesses were sold off by Northrop Grumman as TRW Automotive, which is now part of ZF Friedrichshafen. TRW veterans were instrumental in the founding of corporations like SpaceX.

In 1953, the company was recruited to lead the development of the United States' first ICBM. Starting with the initial design by Convair, the multi-corporate team launched Atlas in 1957. It flew its full range in 1958 and was then adapted to fly the Mercury astronauts into orbit. TRW also led development of the Titan missile, which was later adapted to fly the Gemini missions. The company served the U.S. Air Force as systems engineers on all subsequent ICBM development efforts but TRW never produced any missile hardware because of the conflict of interest. In 1960, Congress spurred the formation of the non-profit Aerospace Corporation to provide systems engineering support to the U.S. government but TRW continued to guide the ICBM efforts.

History
TRW originated in 1901 with the Cleveland Cap Screw Company, founded by David Kurtz and four other Cleveland residents. Their initial products were bolts with heads electrically welded to the shafts. In 1904, a welder named Charles E. Thompson adapted their process to making automobile engine valves and by 1915, the company was the largest valve producer in the United States. Charles Thompson was named general manager of the company, which became Thompson Products in 1926. Their experimental hollow sodium-cooled valves aided Charles Lindbergh's solo flight across the Atlantic.

In 1937, Thompson Motor Products bought J.A. Drake and Sons (JADSON). The company made high-performance valves that were used in many racing engines of the day, including the Miller Offy. Dale Drake (son of J.A. Drake) bought the Offy engine design with his partner Louis Meyer in 1946 and won the Indianapolis 500 twenty-seven times, more than any other engine design.

During the period leading up to World War II, through the end of the Korean war, Thompson Products was a key manufacturer of component parts for aircraft engines, including cylinder valves. The TAPCO plant, owned by the U.S. government but operated by Thompson Products, extended for almost a mile along Cleveland's Euclid Avenue. It employed over 16,000 workers at the peak of WW II production. As jet aircraft replaced piston-engined aircraft, Thompson Products became a major manufacturer of turbine blades for jet engines.

In 1950, Simon Ramo and Dean Wooldridge while working for Hughes Aircraft, led the development of the Falcon radar-guided missile, among other projects. They grew frustrated with Howard Hughes' management, and formed the Ramo-Wooldridge Corporation in September 1953, with the financial support of Thompson Products. The detonation of a thermonuclear bomb by the Soviet Union spurred Trevor Gardner to form the Teapot Committee in October 1953. Chaired by John von Neumann, its purpose was to study the development of ballistic missiles, including ICBMs. Ramo and Wooldridge were committee members, and Ramo-Wooldridge Corp. became the lead contractor of the resulting ICBM development effort, reporting to the United States Air Force.

With continued backing from Thompson Products, Ramo-Wooldridge diversified into computers and electronic components, founding Pacific Semiconductors in 1954. They also produced scientific spacecraft such as Pioneer 1. Thompson Products and Ramo-Wooldridge merged in October 1958 to form Thompson Ramo Wooldridge Inc., unofficially known as "TRW". In February 1959, Jimmy Doolittle became chairman of the board of Space Technology Laboratories (STL), the division which continued to support the Air Force ICBM efforts.

Other aerospace companies believed TRW's Air Force advisory role granted it unfair access to their technologies and in September 1959, Congress issued a report recommending that STL be converted to a non-profit organization. With nearly half of STL's employees, The Aerospace Corporation was formed in June 1960. It headed the Atlas conversion for Mercury, Titan conversion for Gemini, and provided ongoing systems engineering support for the government. The Air Force continued its ICBM work with TRW.

Dean Wooldridge retired in January 1962 to become a professor at California Institute of Technology (Caltech). Simon Ramo became president of the Bunker-Ramo Corporation in January 1964, jointly owned by TRW and Martin Marietta for the production of computers and monitors. Thompson Ramo Wooldridge officially became TRW Inc. in July 1965. Free of anti-competitive restrictions short of ICBM hardware, STL was renamed TRW Systems Group that same month. In 1968, the company entered the credit reporting industry by purchasing Credit Data Corporation and renaming it TRW Information Systems and Services Inc. The Credit Data group was formed in 1970 to compete with Dun & Bradstreet, from the combination of TRWISS and ESL Incorporated to specialize in technical strategic reconnaissance. TRW Information Systems and Services Division (Credit Data) was spun off in 1996 to form Experian. TRW acquired LucasVarity in 1999, then selling Lucas Diesel Systems to Delphi Automotive and Lucas Aerospace (then called TRW Aeronautical Systems) to Goodrich Corporation.

The company was 57th on the Fortune 500 list of highest revenue American companies in 1986 and had 122,258 employees in 2000. It operated in 25 countries.

On 3 February 1986, the TRW plant in Harrisburg, Pennsylvania, burned to the ground in an eight-alarm fire. The damage was estimated to be greater than US$10 million and was the most serious fire to date in the area.

In February 2002, Northrop Grumman launched a US$5.9 billion hostile bid for TRW. Northrop Grumman, BAE Systems, and General Dynamics contended for the company with Northrop's increased bid of US$7.8 billion ultimately being accepted on July 1, 2002. Soon afterward, the automotive assets of LucasVarity and TRW's own automotive group were sold to The Blackstone Group as TRW Automotive.

A portion of TRW's Lyndhurst campus was developed as Legacy Village. The headquarters building became home to the Cleveland Clinic Wellness Institute. The TRW headquarters building was demolished in 2023.

Bill Gates, the founder of Microsoft, says that he got "his first big break" at age fifteen, debugging energy-grid control software for TRW. "It was kind of scary", Gates said, realizing the things the program was going to help operate. "This thing needs to work".

Aerospace

TRW Inc. was active in the development of missile systems and spacecraft, notably, the early development of the U.S. ICBM program under the leadership of the Teapot Committee led by John von Neumann. TRW pioneered systems engineering, creating the ubiquitous N2 chart and the modern functional flow block diagram. It served as the primary source of systems engineering for the United States Air Force ballistic missile programs.

Space exploration
Space Technology Laboratories (STL), then a division of Ramo-Wooldridge Corp., designed and produced the identical payloads for Pioneer 0, Pioneer 1 and Pioneer 2. These were intended to orbit and photograph the Moon, but launch vehicle problems prevented this. NASA launched Pioneer 1 as its first spacecraft on 11 October 1958. It set a distance record from Earth, and provided data on the extent of Earth's radiation belts.

Pioneer 10 and 11 were nearly identical spacecraft, designed and fabricated by TRW Systems Group. They were optimized for ruggedness since they were the first man-made objects to pass through the asteroid belt and Jupiter's radiation belt. Simplicity, redundancy, and use of proven components were essential. As NASA's first all-atomic powered spacecraft, these used plutonium-238 units developed by Teledyne Isotopes. Pioneer 10 carried eleven instruments and Pioneer 11 carried twelve for investigating Jupiter and Saturn, respectively. Data was transmitted back to Earth at 8 watts, 128 bytes/s at Jupiter, and 1 byte/s from further out. Pioneer 10 was the first man-made object to pass the planetary orbits and its last telemetry was received in 2002, thirty years after launch.

TRW Systems Group designed and built the instrument package which performed the Martian biological experiments, searching for life aboard the two Viking Landers launched in 1975. The 15.5 kg system performed four experiments on Martian soil using a gas chromatograph-mass spectrometer (GC-MS) and a combined biological instrument.

Space-based observatories
TRW designed and built the following space observatories:
 * HEAO 1, 2, and 3, with HEAO 2 being the Einstein Observatory, the first fully imaging X-ray telescope put into space
 * Compton Gamma Ray Observatory which is the second of four among NASA's Great Observatories program
 * Chandra X-ray Observatory is the third of NASA's Great Observatories

The teams developing the following observatories continued their work as part of Northrop Grumman Aerospace Systems:

 * SIM Lite space telescope which would have searched for Earth-sized planets in the habitable zones around nearby stars (project canceled)
 * James Webb Space Telescope which is the successor to the Hubble Space Telescope

Satellites
TRW Systems Group designed and manufactured the Vela series of nuclear detection satellites which monitored the 1963 establishment of the nuclear Partial Test Ban Treaty. Subsequently, they produced the Advanced Vela series, first launched in 1967, which could detect nuclear air bursts using instruments actually called bhangmeters. It had the first dual-spin attitude control system with the total system momentum controlled to zero. The Vela and Advanced Vela satellites were the first to alert astronomers to the presence of gamma-ray bursts. They also reported a mysterious apparent nuclear test now called the Vela incident.

First launched in 1970, the company built all twenty-three reconnaissance satellites in the Defense Support Program (DSP), which are the principal components of the Satellite Early Warning System currently used by the United States. These are operated by the Air Force Space Command, and they detect missile or spacecraft launches and nuclear explosions using sensors that detect the infrared emissions from these intense sources of heat. During Desert Storm, for example, DSP satellites were able to detect the launches of Iraqi Scud missiles and provide timely warnings to civilians and military forces in Israel and Saudi Arabia.

The initial seven Tracking and Data Relay Satellite System (TDRSS) were built by TRW to improve communication coverage for the Space Shuttle, International Space Station (ISS), and U.S. military satellites. When first launched in 1983, the TDRS satellites were the largest, most sophisticated communications satellites built at the time. The seventh vehicle in the series was ordered as a replacement when TDRS-B was lost in the Challenger accident.

Launched in 2002, TRW produced the Aqua spacecraft based on their modular standardized satellite bus. A joint project of the U.S. Global Change Research Program (NASA), Japan Aerospace Exploration Agency (JAXA), and National Institute for Space Research (INPE), Brazil, Aqua delivers 750 Gigabytes per day detailing the Earth's water cycle in the oceans, lakes, atmosphere, polar ice caps, and vegetation.

Rocket engines
TRW designed and built the descent engine or (LMDE) for the Apollo lunar lander. Due to the need for a soft landing on the Moon, it was the first throttleable engine for crewed space flight. This, and the requirements for high thrust, low weight, and crushability (in case of landing on a large rock), earned surprising praise from NASA's history pages, considering the complexity of the lunar missions: "The lunar module descent engine probably was the biggest challenge and the most outstanding technical development of Apollo". This engine was used on Apollo 13 to achieve free return trajectory and make a minor course correction after damage to the Service Module.

After the Apollo program Moon landings, the LMDE was further developed into the TRW TR-201 engine. This engine was used in the second stage Delta-P of the Delta launch vehicle for 77 launches between 1972–1988.

Weapons
At the turn of 1964-65, the United States started the ambitious Bushmaster program to create small-caliber assault guns for arming promising infantry fighting vehicles (IFVs) of the American Army. The result of this program was the creation of a whole series of automatic cannons with an external automatic drive in caliber from 25 to 40 mm, which received their own general name Bushmaster.

At the early stage of American research, TRW was one of the companies involved in the development of automatic guns of the Bushmaster program, where, under the leadership of engineer Eugene Stoner, the author of the famous M16 rifle, a 25 mm automatic cannon was developed under the internal designation TRW model 6425, an ordinary system with automatic gas venting and locking the barrel with a rotary bolt is enough.

The TRW-6425 design was later bought from Oerlikon-Bührle, it was improved and manufactured as the Oerlikon KBA 25 mm.

Semiconductors and computers
The Ramo-Wooldridge Corp formed Pacific Semiconductors in June 1954, under the leadership of Harper North who had been head of electronics R+D at Hughes Aircraft Company. The funding for this endeavor from Thompson Products was about ten times their initial investment in Ramo-Wooldridge. The original goal was to produce the recently invented transistor for commercial sales.

In 1957, Howard Sachar and Sanford "Sandy" Barnes invented the Varicap electronic component (also known as the varactor diode) at Pacific Semiconductors. This device reduced the physical size of radio tuners and eliminated the need for moving mechanical parts. This simplified the implementation of remote control TV tuners. Sachar and Barnes were awarded an Emmy in 2007.

The company manufactured the RW-300 for sales in 1959, one of the first "all-transistor" computers with a power supply that used vacuum tubes. The computer was targeted at industrial control applications, with 1024 analog inputs multiplexed to a 1.9K sample/s 10-bit analog-to-digital converter which was transparent to the programmer. It weighed about 600 lb. The real-time operating system was written by John Neblett, and was the intellectual precursor of the RSX-11 operating system for the PDP-11.

The TRW-130 computer was introduced in 1961, and designated the AN/UYK-1 by the U.S. Navy as part of its pre-GPS TRANSIT (NAVSAT) satellite-based location system. It used Doppler shifts to compute a location in about 15 minutes, and had rounded corners to allow installation in submarines.

The Transistor Transistor Logic (TTL) logic gate, which was the electronics industry standard for two decades, was invented by TRW's James L. Buie in 1961.

In 1965, engineers Don Nelson and Dick Pick at TRW developed the Generalized Information Retrieval Language and System, for use by the U.S. Army to control the inventory of Cheyenne helicopter parts. This developed into the Pick Database Management System which is still in use as of 2016.

TRW LSI Products, Inc. was a wholly owned subsidiary formed to commercialize the integrated circuit technology the company had developed in support of its aerospace business. They produced some of the first commercially available digital signal processing ICs including the TDC1008 multiplier-accumulator. They also made the first 8-bit flash ADC IC, the TDC1007, resulting in an Emmy Award for analog/digital video conversion technology. TRW also pioneered gallium arsenide (GaAs) chip applications for local multipoint distribution service (LMDS) systems, radios, and satellite communications.

Music
Bel Canto Stereophonic Recordings, a TRW subsidiary, was a record label active from the mid-1950s to the early 1960s.

In the media
Christopher John Boyce was a TRW employee convicted of selling security secrets to the Soviet Union via the Soviet embassy in Mexico City in the mid-1970s. Boyce and his accomplice, Andrew Daulton Lee, were the subjects of the best-selling 1979 Robert Lindsey book The Falcon and the Snowman, and the 1985 film of the same title.

Representatives from Space Technology Laboratories (STL) present their ICBM expertise to Don and Pete in Mad Men season 2 episode "The Jet Set".

The Star Trek: The Original Series season 1 episode "Operation -- Annihilate!" (13 April 1967) was filmed on the then-TRW campus (now Northrop Grumman's Space Park) in Redondo Beach, California. The two sets of stairs shown are those leading to the cafeteria of Building S. William Shatner had previously filmed at the TRW campus for the Outer Limits episode "Cold Hands, Warm Heart". In the episode, he plays an astronaut for "Project Vulcan". The 1967 sci-fi film Countdown, also filmed at the TRW Space Park.

The TRW building is supposedly one of the credit company buildings demolished in the 1999 film Fight Club. This is because at the time the book was written, TRW was in the business of credit reporting. However, there is no TRW building in Delaware, where the demolition purportedly happens.

TRW equipment/boxes can be seen stored and being unloaded in the film Close Encounters of the Third Kind during scenes filmed at Devils Tower.

Awards

 * 1974 – Nelson P. Jackson Aerospace Award to TRW Systems Group with NASA Ames Research Center for Pioneer 10
 * 1978 – Nelson P. Jackson Aerospace Award for HEAO Program
 * 1988–1989 – Emmy Award for analog/digital video conversion technology to TRW LSI Products
 * 1990 – Goddard Award for Quality and Productivity to Space and Technology Group
 * 1992 – Nelson P. Jackson Aerospace Award to Space and Technology Group with NASA for Compton Gamma Ray Observatory
 * 1997 – TRW Systems Integration Group receives an award for the successful development, deployment and operation of one of the nation's most vital space systems
 * 2001 – Nelson P. Jackson Aerospace Award to TRW Systems Group with NASA Marshall Space Flight Center for Chandra X-ray Observatory
 * 2004 – Nelson P. Jackson Aerospace Award to Northrop Grumman (formerly TRW) Space Technology Sector with NASA Goddard Space Flight Center for TDRSS
 * 2007 – Emmy Award for Varicap to Sycom (formerly Pacific Semiconductors)

Superfund site
In the 1960s and 1970s, TRW stored trichloroethylene (TCE), a critical chemical for cooling and degreasing computer chips, in tanks deep underground in Sunnyvale, California for later use. TCE is also found in household cleaners. As a result of pipe and tank degradation, the tanks leaked into the ground, resulting in contaminated soil and groundwater. TCE was later determined to be toxic to humans at high concentrations. In 2013, The Atlantic referred to the site as a "paved-over environmental disaster zone".

In the 1980s, the US introduced the federal Superfund program to clean up the country's toxic waste sites. The site TRW (now Northrop Grumman) is responsible for is called the 'TRW Microwave site '. The United States Environmental Protection Agency (EPA) worked with TRW to treat the water with ultraviolet light and oxygenation and excavate the contaminated soil. In 1994, a public health study determined that the groundwater was still unacceptably contaminated, which can cause vapor intrusion. The EPA says the site has institutional controls to protect people from contact with affected water. Drinking water in the area comes from Hetch Hetchy and municipal wells.

In the 2000s, a bioremediation method developed by Stanford University using bacteria in molasses to naturally breakdown the TCE into harmless sub-compounds was implemented. Other measures included engineering vapor pathways to avoid direct human contact by releasing it into the air. Jared Blumenfeld, the former EPA director, said that TCE released in the air after the cleanup efforts reduces the concentrations to levels that eliminate health risks. Blumenfeld said that airborne TCE is not ideal, but the cleanup has reduced the toxins by 90%, according to Max Shahbacian, the project's lead at California State Water Resources Control Board before it was transferred to the EPA, and geologist Michael Calhoun.

In 2014 and 2015, a newly required vapor intrusion test of the surrounding residential area, including homes, apartment buildings, and four schools, showed unacceptable levels of TCE. A 2011 study had revealed TCE caused birth defects and cancer by all pathways of exposure. In 2014, the region's congressional representative Anna Eshoo expressed concerns that the EPA had not been properly monitoring the site and notififying residents of a possible health issue. The EPA litigated with the responsible parties in order update its notification and testing measures to warn residents about possible exposure as early as possible and keeping people away from any unsafe areas.

, the site is owned by GI Partners, an investment company, and has been leased by Apple Inc. since 2015 for research and development. The octagonal glass building was renovated in 2014 and made available for occupancy in 2015. The safety of the site was verified by the EPA. In 2016, the Donald Trump administration cut funding the Superfund program by $330 million and EPA funding by more than 30%, resulting in a significant reduction in enforcement and testing. During his presidency, the EPA increased its use of consent decrees, or administrative settlements, to ensure progress continued under the budget cuts, forcing responsible parties to pay for the cleanup. Scott Pruitt, Trump's head of the EPA threatened to cut budgets again for the enforcement. In 2019, the EPA and Philips Semiconductors agreed to a consent decree, with Northrop Grumman as a signatory, to fund the remaining cleanup and monitoring of the site, along with two nearby sites collectively known as the "Triple Site".

In March 2021, Ashley Gjøvik, a former Apple program manager, publicized concerns that the site had not been properly tested since 2015 after receiving an email from Apple notifying employees of forthcoming vapor intrusion testing. An EPA study in 2019 had confirmed the previous remedies effective, but Gjøvik told TechCrunch cracks in the floor were exposing employees to carcinogenic fumes. A site evaluation by the EPA done in August 2021 found that the likelihood for vapor intrusion was low and not expected. Based on field testing done between April 24, 2023 and May 5, 2023, the EPA concluded that vapor intrusion was being prevented.

title: TRW Inc.