148 Fun Facts About Computers

Which daughter of the poet Lord Byron is often called the first computer programmer for her notes on Babbage's Analytical Engine?

Ada Lovelace translated an Italian engineer's paper on the Analytical Engine in 1843 and added far longer notes of her own, including the first published step-by-step sequence of operations for the machine.

What does the acronym RAM stand for in computing?

RAM stands for Random Access Memory: any location can be read or written in about the same time regardless of where it physically sits, unlike sequential tape.

Which 1977 personal computer was one of the first highly successful mass-produced microcomputers?

The Apple II came ready to use, with keyboard, power supply and BASIC built into one case, where the earlier Apple I had been a bare board for hobbyists; it was sold as a computer for ordinary people.

What is the full form of CPU in the context of computer hardware?

Central Processing Unit: early CPUs were built from many separate components, until chip designers in 1971 squeezed the whole CPU onto a single chip, the microprocessor, as nearly all are made today.

What software manages hardware and resources and provides common services for programs?

An Operating System was a later invention: the first computers of the 1940s had none and were programmed directly, and the earliest systems of the 1950s simply ran one batch job after another.

Who is credited with inventing the World Wide Web?

Tim Berners-Lee, a CERN scientist, proposed the Web in March 1989 and by the end of 1990 had written the first browser, web server, HTML and HTTP.

What network security system controls incoming and outgoing traffic based on predetermined rules?

A firewall borrows its name from the fireproof wall built to stop a blaze spreading through or between buildings.

What job was a computer's GPU originally designed to do?

Accelerating image rendering is still a GPU's core job: its many small cores work on thousands of pixels at once, a parallel design since adopted for training AI models.

In computing, what playful name is given to half a byte?

A nibble continues the edible pun of bit and byte, since 'byte' sounds like 'bite'; it is sometimes spelled 'nybble' to match, and holds exactly one hexadecimal digit.

In computing, what is a 'byte' composed of?

A byte is 8 bits largely thanks to IBM's System/360 of 1964, whose success made that size the standard; other machines of the 1960s used six-bit or nine-bit bytes.

What does IDE stand for in the world of programming?

Integrated Development Environment: 'integrated' because it combines the code editor, build tools and debugger, which programmers would otherwise run as separate programs, in one application.

What does VPN stand for?

VPN stands for Virtual Private Network: traffic is wrapped in an encrypted tunnelling protocol so a remote user appears to be plugged straight into the private network.

In computing, what is a 'daemon'?

A background process got the name at MIT in the 1960s after Maxwell's demon, the imaginary being of physics that tirelessly sorts molecules behind the scenes; Unix later inherited the term.

Which programming paradigm builds software from entities that bundle data together with the functions that act on it?

Object-Oriented Programming took its classes and inheritance from Simula, written in 1960s Norway by Ole-Johan Dahl and Kristen Nygaard to simulate real-world systems; the ideas later shaped Smalltalk and Java.

Which kind of chip is built to be configured by the customer after it leaves the factory?

FPGA stands for Field-Programmable Gate Array: it can be reconfigured again and again, so engineers prototype new chip designs on one before committing them to an ASIC, whose logic is fixed for good.

What term describes data sets characterized by the 'three Vs' of volume, velocity and variety?

Big Data outgrew single machines, so tools such as Google's 2004 MapReduce and the freely available Hadoop split the work across clusters of servers processing in parallel.

What type of cyberattack exploits leaked information such as timing, power use or electromagnetic emissions?

A side-channel attack lay behind Meltdown and Spectre, the notorious processor flaws: by watching side effects inside the chip, a rogue program could read passwords and other secrets held by other programs.

In cryptography, what maps data of arbitrary size to fixed-size values, used for integrity checks and password storage?

A hash function only runs one way, so a website can store the hash of your password instead of the password itself and simply compare hashes when you log in.

ENIAC, completed in 1945, was originally built to calculate what for the US Army?

Artillery firing tables were the Army's reason for funding ENIAC, but the war ended before it was ready, and its first real job, in December 1945, was a calculation for the hydrogen-bomb project.

Where was ENIAC formally dedicated in February 1946?

Penn unveiled ENIAC in February 1946 with a showpiece demonstration programmed by two women mathematicians, whose work went uncredited in the press coverage that hailed the machine.

Which Charles Babbage design did London's Science Museum finally build from his plans in 1991?

The Difference Engine No. 2 existed only on paper in Babbage's lifetime; built for his 1991 bicentenary with no more precision than Victorian workshops could manage, it worked, settling whether his design was sound.

Alan Turing's portrait appears on which Bank of England banknote, first issued on his birthday in 2021?

The £50 note carrying Turing was first issued on 23 June 2021, his birthday; he had been convicted in 1952 over a homosexual relationship and received a posthumous royal pardon in 2013.

During World War II, Alan Turing worked at which British codebreaking centre?

Bletchley Park housed the Government Code and Cypher School, where Turing led the attack on German naval messages and designed the bombe, the electromechanical machine that worked out Enigma settings.

Which device, first demonstrated at Bell Labs in December 1947, went on to replace the vacuum tube in most electronics?

The transistor was built by John Bardeen and Walter Brattain as the phone company sought a replacement for its unreliable, power-hungry vacuum tubes; Bell Labs kept it quiet until a press conference in June 1948.

Jack Kilby demonstrated the first working integrated circuit in 1958 while working for which company?

Texas Instruments had hired Kilby only months earlier, so he had no holiday to take when the plant emptied for its summer break; alone in the lab he worked out the idea, and showed a working chip that September.

In 1975 Gordon Moore revised his forecast to say transistors per chip would double roughly how often?

Every two years turned from forecast into target: chipmakers planned their research around Moore's revised 1975 figure, making his observation a self-fulfilling prophecy for decades.

Steve Jobs secured the Apple-1's first order, for 50 machines, from which retailer?

The Byte Shop ordered its 50 machines fully assembled, not as the bare boards hobbyists soldered up themselves; filling that order turned Wozniak's hobby design into Apple's first product.

The original IBM Personal Computer, model 5150, was powered by which processor?

The IBM PC 5150 ran a 4.77 MHz Intel 8088; released on 12 August 1981, its open architecture spawned the PC-compatible industry.

The team that created the IBM PC worked in which Florida city?

Boca Raton was home to the IBM lab whose director, William Lowe, was given a year to ship a PC; to make the deadline his team broke with company habit and built it from off-the-shelf parts.

Windows 1.0, released in November 1985, was originally developed under what working name?

Interface Manager was the planned name until shortly before the 1983 announcement, when it gave way to 'Windows', after the on-screen boxes each program ran in; the product then took two more years to ship.

Which animal is the official mascot of Linux?

A penguin named Tux has fronted Linux since 1996; artist Larry Ewing drew it with free software and lets anyone use or alter the image, asking only to be given credit.

Most of Unix was rewritten in 1973 in which programming language, making it far easier to move to other computers?

C grew up alongside Unix: Dennis Ritchie had its essentials finished by early 1973, and that summer the Unix kernel was rewritten in it, freeing the system from the assembly code of a single machine.

Douglas Engelbart's 1968 presentation unveiling the computer mouse has become known by what nickname?

The Mother of All Demos showed far more than the mouse: Engelbart also premiered on-screen windows, hyperlinks and shared-screen video conferencing, years before any of them reached the public.

Which American gunmaker began producing the first QWERTY typewriters in 1873?

Remington, the arms company, gave the job to its sewing-machine department, so the first QWERTY typewriters looked the part, with painted flowers and a stand like a sewing table's.

IBM's first hard disk drive, a 1956 unit the size of two refrigerators, stored roughly how much data?

A few megabytes, five million characters on fifty spinning disks, was all the one-ton unit held, yet it could find any record in about a second where searching tape had taken far longer.

What was the diameter of the first floppy disks, introduced by IBM in 1971?

8 inches across, the first floppy was a read-only disk IBM devised simply to load control software into its mainframe hardware; the smaller sizes that reached home computers came later.

Intel's 4004 chip was created in 1971 to run what product?

A calculator made by Japan's Busicom was the 4004's first job; Busicom had planned a set of custom chips, but Intel's Ted Hoff proposed a single general-purpose chip that could be programmed for the job.

Colossus, the wartime codebreaking machine, was designed by which General Post Office telephone engineer?

Tommy Flowers built Colossus at the Post Office's Dollis Hill labs and had a second model running days before D-Day; the machines stayed secret for decades, denying him recognition as a computer pioneer.

Colossus was built to crack which German teleprinter cipher?

Lorenz, not the better-known Enigma, was Colossus's target: it carried messages between Hitler and his generals, so breaking it gave the Allies a view into the thinking of the German high command.

Grace Hopper popularised the term "bug" after operators found what trapped in a Harvard Mark II relay?

Operators traced a Mark II error to a moth in a relay around 1947 and taped it into the log book with the note 'First actual case of bug being found'.

Guinness World Records lists which machine as the best-selling desktop computer model of all time?

The Commodore 64 was sold in ordinary retail stores, not just by specialist computer dealers; estimates of how many were bought range from 12.5 million to 30 million.

IBM's chess computer took its final name as a play on which IBM nickname?

Big Blue, IBM's nickname, gave Deep Blue its name; the machine was previously Deep Thought, after the computer in The Hitchhiker's Guide to the Galaxy, and in 1997 it beat world champion Garry Kasparov.

The Alto, which pioneered the graphical user interface in 1973, was developed at which research centre?

The Alto was built at Xerox PARC in Palo Alto, pairing a graphical screen of windows and icons with a mouse; Apple's engineers saw it on visits to the lab, and its ideas resurfaced in the Macintosh.

The Altair 8800 grew famous after appearing on the cover of the January 1975 issue of which magazine?

The Altair 8800 was the cover story of Popular Electronics' January 1975 issue; its Altair BASIC, written by Gates and Allen, was Microsoft's founding product.

The Antikythera mechanism, often called the earliest known analog computer, was designed to calculate what?

Astronomical positions were only part of it: scans of the corroded bronze gears, recovered from an ancient shipwreck, revealed a dial that also tracked the four-year cycle of the Olympic Games.

Which German engineer built the Z3, the first working programmable relay computer, in 1941?

Konrad Zuse built the Z3 in Berlin, cut off from computing work elsewhere; the machine was destroyed by Allied bombing, and the Nazi government declined to fund the electronic successor he proposed.

In which English city did the first stored-program computer run its first program in 1948?

Manchester's 'Baby' ran its first program on 21 June 1948 as a mere test rig for a new kind of memory, yet by 1951 it had grown into the Ferranti Mark 1, sold to customers as a standard product.

Which British tea-shop firm's LEO I ran the world's first routine office computer job in 1951?

J. Lyons & Co. helped pay to finish a university research computer, then built its own version; from 1951 LEO worked out what the firm's bread and cakes cost to make.

The Atanasoff-Berry Computer, tested in 1942, was developed at which university?

Iowa State physicist John Atanasoff built it with student Clifford Berry; decades later, in 1973, a US court threw out the ENIAC patent, finding its inventors had drawn key ideas from Atanasoff's machine.

Which 2016 film follows the Black women mathematicians, known as 'computers', who calculated NASA's early spaceflights?

Hidden Figures follows Katherine Johnson, Dorothy Vaughan and Mary Jackson, whose job title really was 'computer': the word meant a person who calculates long before it meant a machine.

Which Harvard physicist conceived the Mark I, the room-sized machine that IBM built for the university in 1944?

Howard Aiken's press release named himself as sole inventor; IBM chairman Thomas Watson, whose engineers had built the machine, was furious at the lack of credit, and Aiken built his later machines without IBM.

In 1952, CBS used a UNIVAC I on live television to predict the outcome of what?

CBS used UNIVAC I on election night 1952 to forecast the presidential election; with a few percent of the vote counted it called an Eisenhower landslide that the network doubted and delayed airing.

EDSAC, which ran its first program in May 1949, was built by Maurice Wilkes's team at which university?

Cambridge's Mathematical Laboratory ran EDSAC's first program, a table of squares, on 6 May 1949; team member David Wheeler devised the subroutine there, a building block of programming ever since.

Hollerith's tabulating machines were built to speed up which US government task?

The census of 1890 was the machines' first big job; their success led countries from Canada to Russia to adopt them for their own counts, and Hollerith's firm grew into IBM.

Joseph Marie Jacquard's loom of the early 1800s controlled its woven patterns using what?

Punched cards laced into a chain told Jacquard's loom which threads to lift, row by row; Babbage later borrowed the idea to feed programs and data into his Analytical Engine.

The ARPANET's first message in 1969 crashed after 'lo', the first two letters of which intended word?

Login was all UCLA student Charley Kline meant to type; the receiving computer crashed after two letters, so the network's first message was 'lo', as in 'lo and behold', and the full word got through an hour later.

Robert Metcalfe's 1973 design for wired local networks is named after which discarded physics concept?

Luminiferous aether was the invisible medium once thought to carry light through space; Metcalfe recycled the word 'ether' for the shared cable carrying his network's signals, hence Ethernet.

Which programming language did John Backus's team at IBM release in 1957 so scientists could stop hand-coding machine instructions?

Fortran, short for 'formula translation', let scientists write something close to algebra instead of hand-coding every machine instruction, opening programming to people who were not specialists.

Guido van Rossum named his 1991 programming language after which British comedy series?

Monty Python's Flying Circus scripts were Guido van Rossum's reading while he built the language; he wanted a name that was short, unique and slightly mysterious, so Python it was.

Apple's '1984' commercial introducing the Macintosh was directed by which filmmaker?

Ridley Scott, fresh from Blade Runner, directed '1984'; Apple's board disliked it so much that the company tried to sell off its Super Bowl airtime, yet the one national airing became advertising legend.

Which 24-pound machine of 1981 is regarded as the first commercially successful portable computer?

The Osborne 1 sold on value: its $1,795 price included a bundle of business software worth about $1,500 on its own.

Compaq's first product, shipped in 1983, achieved IBM PC compatibility through what?

A reverse-engineered BIOS, rewritten from scratch in a clean-room process, let Compaq's 1983 portable run IBM PC software legally; its success opened the floodgates for IBM-compatible clones.

What was the launch price of the first Raspberry Pi Model B in February 2012?

$35 bought the Model B on launch day, 29 February 2012; its makers hoped a cheap computer would revive young people's fading programming skills, and demand crashed a supplier's website.

Sir Clive Sinclair's ZX Spectrum home computer was manufactured in Dundee, Scotland, by which company?

Timex assembled the Spectrum at its Dundee plant, but demand swamped it: within weeks of launch tens of thousands of mail orders were waiting, and Sinclair began selling through high-street chains as well.

The 1988 Morris worm was written by a graduate student at which university?

Robert Tappan Morris, a Cornell graduate student, released it from MIT to muddy the trail and became the first person convicted of a felony under the 1986 Computer Fraud and Abuse Act.

The ILOVEYOU worm of May 2000 was created by a college dropout from which country?

The Philippines had no law against hacking in 2000, so prosecutors had to drop every charge against the worm's creator, Manila student Onel de Guzman; the country passed one soon afterwards.

The Stuxnet worm damaged Iran's nuclear programme by wrecking which equipment?

Stuxnet made Natanz's gas centrifuges spin at damaging speeds while reporting normal readings; it exploited four Windows zero-day flaws to reach Siemens Step7 software controlling the PLCs.

Flash memory was invented in 1980 by Fujio Masuoka at which company?

Toshiba colleague Shoji Ariizumi is said to have named it 'flash' because wiping a whole chip at once reminded him of a camera flash; Masuoka presented the design publicly in 1984.

Claude Shannon's 1937 MIT thesis showed switching circuits could implement whose logic?

George Boole's algebra of true and false, Shannon showed, could be wired up with ordinary switches, the insight behind every digital circuit; it has been called possibly the most important master's thesis of the century.

Which unsold Apple computer, about 2,700 of them, was buried in a Utah landfill in 1989?

The Lisa, launched in 1983 at $9,995, sold so poorly that Apple buried its last 2,700 in a Logan landfill, taking a tax write-off on machines nobody would buy.

The first web server and browser were developed at CERN on a computer from which company?

NeXT was the company Steve Jobs founded after being forced out of Apple in 1985; one of its black cube computers at CERN became the world's first web server.

Michael Dell founded PC's Limited in 1984 from a dorm room at which university?

At UT Austin, eighteen-year-old freshman Michael Dell turned a hobby of building custom PCs into a business so brisk that he dropped out at the end of his first year to run it full time.

The 'traitorous eight' who founded Fairchild Semiconductor in 1957 left whose lab?

William Shockley's management style was so hard to bear that the eight asked the lab's backer to rein him in; when that failed they resigned together in September 1957 and set up Fairchild Semiconductor.

Intel's name is a contraction of which two words?

Integrated Electronics was shortened to Intel when Robert Noyce and Gordon Moore left Fairchild Semiconductor in 1968 to start a chip company of their own.

Alan Turing's 1950 paper introduced his famous test under what name?

Turing's 1950 paper 'Computing Machinery and Intelligence' called it the imitation game: in its original form an interrogator questions a man and a woman in another room and tries to tell which is which.

Which statement did Edsger Dijkstra's 1968 letter famously brand 'considered harmful'?

Go To got its famous label from the journal's editor, Niklaus Wirth: Dijkstra had called his piece 'A Case Against the Goto Statement', and the new headline inspired countless 'considered harmful' imitations.

Donald Knuth paid $2.56 for each error found in his books because 256 pennies make what?

One hexadecimal dollar is 256 cents, counting in base 16 instead of base 10; winners so rarely cashed the cheques that when fraud fears ended them in 2008, Knuth switched to certificates from his imaginary Bank of San Serriffe.

Which symbol did Ray Tomlinson pick in 1971 to separate a username from a machine name?

The at sign, @, let Tomlinson's adapted SNDMSG program tell a user's name from the host computer, so mail could travel between different machines on the ARPANET for the first time.

Google's name is a play on 'googol', the number written as 1 followed by how many zeros?

100 zeros follow the 1 in a googol; Page and Brin wanted a name that suggested indexing an immense amount of data, and the spelling 'Google' is said to come from a slip while checking if the web address was free.

Larry Page and Sergey Brin ran Google in 1998 from a garage rented from which future tech executive?

Susan Wojcicki rented them her Menlo Park garage, then joined as Google's sixteenth employee and went on to become chief executive of YouTube.

DEC's PDP-8 of 1965, priced under $20,000, was an early hit in which new class of smaller computers?

Minicomputer became the word for machines like the PDP-8, small and cheap enough for a single lab or factory to own; it was one of the most successful computers of its decade and ran to a dozen later versions.

The Apollo Guidance Computer was among the first computers built from which components?

Silicon integrated circuits were newly invented when MIT built the Apollo computer around them; its software was stored in 'rope' memory, with factory workers, mostly women, threading every bit into place by hand.

Apollo astronauts' DSKY unit, pronounced 'DISS-kee', was short for what?

Display and Keyboard was the astronauts' only way to talk to the computer: they punched in two-digit codes for a 'verb', the action, and a 'noun', the thing to act on.

Which Shanghai-born physicist patented a core-memory device developed at Harvard in 1949?

An Wang filed the patent alone because Harvard had no interest in promoting its lab's inventions; he later sold it to IBM and founded Wang Laboratories in 1951.

Spacewar!, the 1962 space-combat game from MIT, was written for which DEC computer?

The PDP-1 at MIT was Spacewar!'s home; Steve Russell wrote the first version in 1962 and fellow hackers kept improving it, and the game, more than any serious use, is what made the machine famous.

VisiCalc, released in 1979, was the first program of which kind for personal computers?

VisiCalc, by Dan Bricklin and Bob Frankston, was the first spreadsheet program for personal computers; people bought a machine just to run it, turning a hobbyist's gadget into a serious business tool.

Microsoft's Windows 95 launch campaign licensed which Rolling Stones song?

'Start Me Up' was a nod to the new Start button; Microsoft reportedly paid the Rolling Stones several million dollars for the rights.

Which wireless technology was named in 1999 as a catchier label than IEEE 802.11?

Wi-Fi was picked as a catchier label than 'IEEE 802.11'; the people who chose it say it never stood for 'wireless fidelity', though some dictionaries give that origin.

Microsoft bought the rights to 86-DOS, the basis of MS-DOS, from which company in 1981?

Seattle Computer Products' Tim Paterson had knocked it together while waiting for another system and called it QDOS, the Q and D standing for 'Quick and Dirty'; Microsoft bought it a month before the IBM PC went on sale.

Linus Torvalds began writing Git in 2005 after losing free use of which tool?

BitKeeper's owner withdrew its free licence in April 2005, accusing programmer Andrew Tridgell of reverse-engineering its protocols; Torvalds began writing Git that same month.

The first known 'hello, world' program appeared in a 1972 tutorial for which language?

Brian Kernighan's 1972 'A Tutorial Introduction to the Language B' printed 'hello, world'; he reused the example in a 1974 Bell Labs C memo and the 1978 C book that made it famous.

An IPv4 address is how many bits long?

An IPv4 address is 32 bits, written as four 8-bit octets; that allows about 4.29 billion addresses, too few for the global Internet, forcing the move to 128-bit IPv6.

IBM's Watson beat champions Ken Jennings and Brad Rutter in 2011 on which quiz show?

Jeopardy champions Jennings and Rutter lost the February 2011 match to Watson, which played with no internet connection, answering only from documents stored in its own memory.

Joseph Weizenbaum's 1960s chatbot ELIZA was named after a character from which play?

Weizenbaum named it after Eliza Doolittle of Shaw's Pygmalion: like her learning an upper-class accent, the program could be incrementally improved by its users.

Which researcher co-coined the term CAPTCHA and went on to co-found the language app Duolingo?

Luis von Ahn followed CAPTCHA with reCAPTCHA, which put all that typing to work helping to digitise old books; Google bought it in 2009.

In 2019 Google said its Sycamore chip had reached which milestone?

Quantum supremacy means beating any classical computer at some task: Google said Sycamore took 200 seconds over one that would need 10,000 years, though rival IBM countered that 2.5 days would do.

Years before Britain's wartime codebreakers, mathematicians from which country first cracked the Enigma cipher in 1932?

Poland's Marian Rejewski worked out Enigma's wiring by mathematics in 1932 without ever seeing the military machine; his team's methods became the foundation for Britain's wartime codebreaking.

MIT's Whirlwind I, operational in 1951, began as a Navy project to drive what?

Whirlwind began as a Navy flight-simulator project in the mid-1940s before becoming a digital computer; it was one of the first real-time computers and led to the SAGE air-defence system.

The world's first webcam was set up at the University of Cambridge in 1991 to keep watch on what?

A coffee pot in the lab's Trojan Room was filmed so that colleagues elsewhere in the building could skip a wasted trip to an empty jug. The camera stayed on until 2001.

Apple's first company logo, drawn in 1976, pictured which scientist?

Isaac Newton sat under an apple tree in an ornate drawing by co-founder Ron Wayne. In 1977 it gave way to Rob Janoff's rainbow-striped apple with a bite taken out.

Jensen Huang and two fellow engineers agreed to start which chip company in a booth at a Denny's diner?

Nvidia took shape in late 1992 over sketches in a booth at Denny's, the chain where a teenage Huang had worked as a dishwasher and waiter. A plaque now marks the table.

Which card game did Microsoft bundle with Windows 3.0 in 1990, partly to teach new users to drag with a mouse?

Solitaire was written by a summer intern, Wes Cherry, and Microsoft hoped it would soothe people intimidated by Windows. His 'boss key', which hid the cards behind a fake Excel sheet, was cut.

Mozilla's Firefox browser, whose logo shows a fox, takes its name from a nickname for which other animal?

Red panda is the animal behind the name, and it became the project's mascot even though the logo shows a stylised fox. The browser had already been called Phoenix and Firebird.

Tux, the cheerful mascot of the Linux kernel drawn by Larry Ewing in 1996, is which kind of animal?

A penguin was Linus Torvalds's own idea: he joked that he caught 'penguinitis' after one nibbled him at a zoo in Canberra, Australia, in 1993.

Ronald Wayne, Apple's little-known third co-founder, gave up his 10% stake in the company in 1976 for what sum?

$800 was all Wayne took for a share that would later have been worth a vast fortune. He withdrew after twelve days, fearing creditors could seize his assets if Apple ran up debts.

In 2001: A Space Odyssey, which sentient computer controls the spacecraft Discovery One and turns on its crew?

HAL 9000 sits one letter before IBM at every position, a link both Stanley Kubrick and Arthur C. Clarke denied intending. As the machine is shut down it sings an old tune about a bicycle built for two.

Which online retailer was first incorporated in 1994 as Cadabra and run from a garage in Bellevue, Washington?

Amazon replaced the name within months because a lawyer misheard Cadabra as 'cadaver'. Jeff Bezos picked the world's biggest river for what he planned as its biggest bookstore.

Which puzzle game did Soviet programmer Alexey Pajitnov name partly after his favourite sport, tennis?

Tetris joins 'tetra', for the four squares in every piece, to tennis. Pajitnov got the idea from a pentomino puzzle set, then cut its twelve shapes down to seven simpler ones.

Which Homebrew Computer Club engineer built a famous 1976 machine and later competed on Dancing with the Stars?

Steve Wozniak designed the Apple I largely to show off to fellow hobbyists at the club. In 2009 he danced in the eighth season of the TV contest with partner Karina Smirnoff.

Which animation studio began as Lucasfilm's computer Graphics Group before Steve Jobs funded its 1986 spin-off?

Pixar first tried to survive as a hardware company, selling its Pixar Image Computer to government, scientific and medical customers.

In the film WarGames, the computer WOPR learns that nuclear war is unwinnable by playing which game against itself?

Tic-tac-toe played against itself gets the machine nowhere, so it concludes of nuclear war that 'the only winning move is not to play'. It then suggests a nice game of chess.

In The Hitchhiker's Guide to the Galaxy, which number does the computer Deep Thought give as the ultimate answer?

42 takes Deep Thought seven and a half million years to work out, and it then points out that the beings who asked never knew what the question was.

Which online scam, first documented on AOL in 1995, uses fake emails or websites to trick people out of passwords?

Phishing is thought to take its 'ph' spelling from the older hacker term 'phreaking'. An early tool called AOHell let users pose as AOL staff and message victims asking for their passwords.

WannaCry, which disrupted Britain's National Health Service in May 2017, was which kind of malicious software?

Ransomware like WannaCry encrypts a victim's files and demands payment in Bitcoin to release them. Researcher Marcus Hutchins halted the outbreak within hours by registering a kill-switch web address.

Which company began in 1939 in a one-car garage in Palo Alto, selling audio oscillators to Walt Disney Studios?

Hewlett-Packard owes the order of its name to a coin toss between its two founders. Disney bought eight of the garage-built oscillators to test cinema sound systems for the film Fantasia.

Before co-founding Apple, Steve Jobs worked as a technician at which video game company, the maker of Pong?

Atari hired Jobs as a technician in Los Gatos, California. Its founder, Nolan Bushnell, was later offered a one-third stake in Apple for $50,000 and said no.

Bill Gates and Paul Allen founded Microsoft in 1975 in which city, home of the Altair 8800's maker MITS?

Albuquerque drew Allen first, and Gates soon quit Harvard to join him there. In 1979 the firm left for Bellevue, Washington, because top programmers were hard to recruit in New Mexico.

Which small data file did Netscape's Lou Montulli devise in 1994 so websites could keep a shopping cart?

Cookie was Montulli's own coinage, borrowed from the 'magic cookie', a packet of data that Unix programmers passed to a program and got back unchanged.

Which standard message goes with the HTTP status code 404, shown when a server cannot provide a requested page?

Not Found means the browser reached the server but got nothing back for that address. A server may also send it when it would rather not reveal whether the page exists at all.

Which number system, linked by Leibniz to the I Ching's hexagrams, do digital computers use to store all data?

Binary needs only the characters 1 and 0, which suits circuits that are simply on or off. Leibniz's 1703 article on it also discussed the ancient Chinese figures of Fu Xi.

Which text-encoding standard, which also defines emoji, aims to cover all of the world's writing systems?

Unicode gives each character a unique number called a code point, so text survives the trip between devices. It largely replaced a tangle of incompatible character sets.

Which term, suggested by Christine Peterson in 1998, describes software whose code anyone may study, modify and share?

Open source was chosen to escape the ambiguity of 'free software', where 'free' could mean either freedom or zero price. The new label was meant to appeal to the business world.

Which language did Brendan Eich create at Netscape in 1995, first shipping in a browser beta as LiveScript?

JavaScript got its final name as a marketing ploy, in Eich's own view, because Java was the fashionable new language of the dot-com boom. The two differ greatly in design.

Which Chinese company, founded as Legend, bought IBM's PC business and its ThinkPad laptops in 2005?

Lenovo blends 'Le' from Legend with 'novo', a Latin form of 'new'. After taking over the ThinkPad line it expanded rapidly outside China.

Which French thinker built a mechanical adding machine as a teenager in 1642 to ease his father's tax calculations?

Blaise Pascal was not yet 19 when he built the Pascaline, a machine that could add and subtract. A programming language was later named after him.

Which calculating tool, based on logarithms, did engineers rely on until pocket calculators arrived in the 1970s?

Slide rule users multiplied and divided by sliding marked rulers against one another. The tool became largely obsolete once the first handheld scientific calculator, launched in 1972, grew cheap.

Which file-sharing service, launched in 1999 by Shawn Fanning, was sued by Metallica and shut down in 2001?

Napster drew Metallica's lawsuit after an unreleased demo of the band's song 'I Disappear' spread across the service and reached radio. It filed for bankruptcy in 2002.

Which software company is named after a creek that ran behind co-founder John Warnock's house in Los Altos?

Adobe borrowed the creek's name, and adobe is a Spanish word for mudbrick. The company was set up in 1982 to develop and sell the PostScript page description language.

Which networking company's logo of vertical bars is a stylised picture of the Golden Gate Bridge?

Cisco was written in lower case in the firm's early years, at its engineers' insistence, because it was simply the tail of San Francisco's name. The logo's bars trace the bridge's two towers.

Which Pacific island nation earns a share of its government revenue by licensing its internet country code, .tv?

Tuvalu struck a deal in 1998 under which a registrar agreed to pay US$50 million upfront to market the domain. By 2019 the royalties made up 8.4% of government revenue.

Which MIT software chief was photographed in 1969 beside printouts of the Apollo guidance code her team wrote?

Margaret Hamilton is also credited with coining the term 'software engineering', using it to set her craft alongside hardware and other kinds of engineering.

Which term was coined in John McCarthy's proposal for a 1956 workshop at Dartmouth College that founded a new field?

Artificial intelligence was the banner for a summer gathering organised with Marvin Minsky, Nathaniel Rochester and Claude Shannon, now widely seen as the founding event of the field.

ARPANET, the 1969 network that grew into the internet, was set up by a research agency of which US department?

Defense paid for it through its agency ARPA, whose 1960s director Charles Herzfeld said the aim was not to survive a nuclear attack but to let scattered researchers share a few powerful computers.

James Gosling first named the Java programming language after which tree that stood outside his office?

Oak gave way to the working name Green and finally to Java, a name borrowed from a hot drink grown in Indonesia.

The word 'algorithm' comes from the Latinised name of which 9th-century Persian mathematician?

Al-Khwarizmi wrote a book on Indian arithmetic whose Latin version opened 'Dixit Algoritmi', meaning 'Thus spoke Al-Khwarizmi'. The word 'algebra' comes from the title of another of his works.

Which Hungarian-born mathematician wrote the 1945 EDVAC report that gave the stored-program computer design its name?

John von Neumann was the only author named on the unfinished 'First Draft', so the architecture took his name, although the report described designs by John Mauchly and J. Presper Eckert.

Which kind of program, named by Grace Hopper's team in 1952, translates human-readable code into machine code?

Compiler was the word Hopper's team at Remington Rand coined for their A-0 system, though by modern standards it worked more like a loader or linker.

The hill in Bliss, Windows XP's default wallpaper, was bare grass because pests had forced out which crop?

Grapes grew on the California hill until a phylloxera infestation forced the vineyard to be cleared. Charles O'Rear photographed the bare slope in January 1996, and vines have since returned.

The computing terms big-endian and little-endian come from a feud over cracking eggs in which classic novel?

Gulliver's Travels has the people of Lilliput feuding over which end of a boiled egg to break. Engineer Danny Cohen borrowed the terms in a 1980 note titled 'On Holy Wars and a Plea for Peace'.

Which database company took its name from the code name of a 1977 project for the CIA, its first customer?

Oracle was the code name of the CIA database job, and the founders got permission to reuse it for their product. The firm itself adopted the name only in 1983, to match its flagship database.

Which Intel processor line was recalled in 1994 after a maths professor found errors in its floating-point division?

Pentium chips returned wrong results for certain divisions, as Thomas Nicely of Lynchburg College showed. Replacing them in the first full recall of a computer chip cost Intel $475 million.

Which European rocket was lost on its 1996 maiden launch when software forced a 64-bit number into a 16-bit slot?

Ariane 5 reused inertial reference code from its slower predecessor, so its higher horizontal velocity overflowed the conversion. The rocket veered off course 37 seconds after lift-off and self-destructed.

Which 1970s supercomputer sat inside a ring of benches that covered its power supplies and cooling system?

Cray-1 had its whole chassis bent into a C so that speed-critical parts sat on the inside edge, where the wires were shortest. More than 80 were sold, at $5 million to $8 million each.

Which Gary Kildall creation of 1974 was the standard software platform for microcomputers until the IBM PC arrived?

CP/M lost its crown when IBM turned to Microsoft instead for its PC, and DOS displaced it. The name first stood for Control Program/Monitor.

Which microprocessor, the cheapest on sale at its 1975 launch, ran the BBC Micro and the Nintendo Entertainment System?

MOS 6502 chips cost just $25, and a variant drove Nintendo's console. The designers had earlier worked on Motorola's 6800 and built a simpler, faster version of it.

Brain, regarded as the first IBM PC virus, was written in 1986 by two brothers in which country?

Pakistan was home to Basit and Amjad Farooq Alvi, who said they wrote Brain to protect their medical software from copying. The virus even carried their Lahore address and phone numbers.

Which Fred Brooks book, drawn from IBM's OS/360, argues that adding programmers to late software delays it?

The Mythical Man-Month argues that newcomers take time to learn a project and every extra person adds lines of communication. By its formula, a team of 50 developers has 1,225 pairs who may need to talk.

Which English ambient music pioneer did Microsoft approach in 1994 to compose the six-second chime of Windows 95?

Brian Eno made 84 tiny pieces to meet a brief asking for music that was inspiring, universal, optimistic and futuristic. He later admitted he wrote the winner on a Macintosh.