Centipede | Code Like It's 198x

Centipede began as one sentence in a binder. Atari’s coin-op engineers kept a book of game ideas, and one page read, in Dona Bailey’s memory of it, “A multi-segmented creature comes onto the screen and breaks into pieces when shot by the player.” Bailey, a programmer who had arrived from General Motors in June 1980, took it as her first project, with Ed Logg as project director. The game they made reached the arcades in 1981 and became Atari’s second best-selling coin-op, about 50,000 machines according to Video Games in 1982, behind only Asteroids. It also drew women players in numbers the trade noticed, and it was the first arcade game to use Atari’s new small trackball.

Fast facts

Developer and manufacturer: Atari’s coin-op division.
Programmers: Dona Bailey and Ed Logg; Logg was project director.
Program begun: 19 July 1980; the program and the attract screen carry a 1980 copyright.
Arcade release: 1981. Video Games dated it June 1981.
Controls: a trackball and one fire button; the program also reads a joystick where no trackball is fitted.
Hardware: a 6502 processor, 8K of program, a colour raster monitor mounted upright, 16 moving objects, Atari’s POKEY chip for all the sound, and an EAROM to keep the top scores with the power off.
Sequel: Millipede, shown to operators at the end of 1982.

One page in the idea book

Bailey told the children’s magazine Blip in 1983 that the idea was not hers: it came from Atari’s “big project-idea book”. She spent months on it, ten or more hours a day. “The game took over my life,” she said. “It became an obsession. I started dreaming about it at night.” She credited others, Logg above all: he “had dreamed up most of Asteroids”, Blip explained, “and he was the Centipede project director.” The program’s own header lists them together: “PROGRAMMER: DONA BAILEY / ED LOGG”, “DATE INITIATED: JULY 19,1980”.

The mushrooms came from a debugging aid. To see where segments had been hit, Bailey marked each spot on the screen with a small block. Someone looked over her shoulder at a screen full of blocks and said, “Hey, look at the maze game you’ve got there!” She realised he was right. “We decided to leave it as a maze game,” she told Blip, “but we changed the shape of the little blocks to mushrooms. Every time a centipede section got shot, a mushroom would be left in its place.”

The look was hers too. “I really like pastels,” she told Video Games, “which is why there are so many pinks and greens and violets in Centipede. I really wanted it to look different, to be visually arresting.” Years later she told the writer of an Edge history that Namco’s Galaxian had moved her: “I adored Galaxian, I thought it was intensely beautiful.”

The trackball

The team started with buttons. “I panicked at the thought of buttons,” Bailey told Blip. “I’ve never been able to use them comfortably.” A joystick did not suit her either. “I remembered seeing some trak balls lying around the labs. At the time, Missile Command was about the only game that used a trak ball. But I thought it would be great for Centipede. So I kept pushing until they gave us one.” In a 2015 interview with the Arkansas Times she added that the side-to-side movements were so large that a joystick clunked against its stops, while a trackball let the player cross the screen in one sweep.

The ball Centipede got was new. Electronic Games reported in its first issue that the game was “the first commercial arcade machine to sport the new smaller track-ball controller”, about the size of a pool cue ball and “much easier to grip” than the grapefruit-sized one on earlier games. Atari expected to use it on every future coin-op that would have had the big one.

How it plays

The player’s gun sits in the bottom few rows of the screen and can move up and down as well as sideways. Holding the fire button fires again as soon as a shot is free. Ed Logg’s documentation of May 1981 describes the rest:

The centipede enters at the top and turns whenever it hits something, so each mushroom is a place where it changes direction and drops a row. Shooting a segment splits it into two centipedes and leaves a mushroom behind. At the bottom the centipedes start back up, and new heads appear from the sides if the player is slow. Each new wave has one segment fewer and an extra fast head.
The spider zigzags across from one side of the screen to the other on a random path, eating the mushrooms it passes over, and is worth 300, 600 or 900 points depending on how close it is to the player.
The flea drops down the screen whenever the player’s area has too few mushrooms, leaving new ones behind it. It takes two hits: the first only speeds it up.
The scorpion crosses from the fourth wave on and poisons the mushrooms it touches. A centipede that runs into a poisoned mushroom heads straight for the bottom.

A body segment scores 10 points and a head 100; a mushroom is worth one point. Destroying a whole centipede changes the screen’s colours and sends in the next. The high score table holds eight scores with three initials each. Operators could set the game to English, German, French or Spanish.

Who played it

Centipede arrived when arcades were changing. Electronic Games asked its readers for their favourites in its first issue and published the women’s answers in May 1982: Pac-Man first among coin-ops, Carnival second, Centipede third. The same article reported that Ok-Soo Han, whose favourite game was Centipede, had won at an Atari tournament for the game in Chicago.

The two programmers remembered this differently. “Centipede was definitely aimed at the women’s market,” Logg told Video Games in 1983. “I’m not sure that without Dona’s viewpoint it ever would have made it there.” Bailey told Blip that no one set out to make it appeal to women; she noticed it only once the game was out. “I’d be introduced to a guy as the designer of Centipede, and he’d say, ‘Oh, yeah, my girlfriend likes that game,’ or ‘My wife likes that game.’ But I hardly ever heard a guy say, ‘I like it.’”

By 1982 it was famous enough for a novelty album: Buckner and Garcia’s Pac-Man Fever included “Ode to Centipede”.

Home versions

Atari converted the game for its own machines first. ANALOG Computing announced the Atari 400 and 800 cartridge in January 1982 for June that year, at $44.95, needing only 8K, and called it “VERY close” to the arcade game. Video Games reviewed the Atari 5200 version among that console’s first cartridges in February 1983 as “another very faithful coin-op translation” with “mushrooms, fleas, spiders, and scorpions”, although the 5200’s self-centring joystick made the spiders and fleas hard to hit until Atari’s promised trackball arrived. The Atari 2600 version was planned for March 1983, ANALOG reported.

From the end of 1983 Atarisoft, Atari’s new label for other companies’ machines, brought Centipede to the ColecoVision and Intellivision; its first release list also named versions for the Commodore 64, the VIC-20, the Apple II, the IBM PC and the TI-99/4A. Computer & Video Games reported the same range coming to British machines, the Spectrum and BBC Micro among them. A version for the Atari 7800 was among the games shown at that console’s press launch in 1984.

Other people’s versions came sooner. In December 1981 a Norfolk firm, cK’tronics, was already advertising a Centipede for the ZX80 and ZX81 in Your Computer, “the first implementation of the popular arcade game on any Micro anywhere”, by its own account.

Millipede

Logg wrote the sequel, Millipede, on his own, beginning in April 1982, as the Ed Logg entry tells. Atari showed it at the AMOA trade show at the end of that year. Atari Age previewed it for “Centipede fans” in January 1983 with its dragonflies, mosquitoes and inchworms, and the DDT bombs that wiped out every insect nearby.

Later

The program listing and its documentation were published by historicalsource on GitHub in October 2021, without a stated licence. They show the program’s 1980 copyright alongside release papers dated May 1981. In 2020 The Strong National Museum of Play inducted Centipede into its World Video Game Hall of Fame.

Sources

Blip, vol. 1 no. 4, May 1983, profile of Dona Bailey, pp. 6–8: the idea book and its one-line description, Logg as project director, the months of work, the blocks that became mushrooms, buttons, joystick and trackball, Missile Command, the men whose girlfriends and wives liked the game.
Anne Krueger, “Welcome to the Club”, Video Games, vol. 1 no. 6, March 1983, pp. 51–54 and 81: Bailey’s move from General Motors in 1980; the pastels; Logg’s “women’s market” quote.
Steve Bloom, “The incredible, incredible story of Atari”, Video Games, vol. 1 no. 3, December 1982, p. 49: Centipede dated June 1981; Atari’s second best-selling coin-op at 50,000 units.
“‘Cue Ball’ Controller Makes Coin-Op Debut”, Electronic Games, vol. 1 no. 1, December 1981, p. 73: the first arcade game with the smaller trackball.
Joyce Worley, feature on women arcaders, Electronic Games, vol. 1 no. 3, May 1982, pp. 30–32: the women’s reader poll and Ok-Soo Han.
ANALOG Computing, issue 5, January 1982, p. 9: the 400/800 cartridge for June 1982 at $44.95.
ANALOG Computing, issue 9, January 1983, p. 79: the VCS version planned for March 1983.
Video Games, vol. 1 no. 5, February 1983, p. 92: the 5200 version and its joystick.
Electronic Fun with Computers & Games, vol. 2 no. 2, December 1983, p. 104: Atarisoft’s first release list; Video & Computer Gaming Illustrated, January 1984, p. 8: Atarisoft’s ColecoVision and Intellivision releases; Ahoy!, issue 3, March 1984, p. 65: the Atarisoft Commodore 64 version reviewed; Computer & Video Games, issue 27, January 1984, news pages: Atarisoft in Britain.
ANALOG Computing, issue 21, August 1984, p. 9: Centipede at the Atari 7800’s press launch.
cK’tronics advertisement, Your Computer, December 1981, p. 58: ZX80/ZX81 Centipede.
Atari Age, vol. 1 no. 5, January 1983: Millipede previewed; Electronic Fun with Computers & Games, vol. 1 no. 4, February 1983, p. 28: Millipede at the AMOA show.
Edge issue 217, August 2010, pp. 84–86, “When videogames ruled the world”: Bailey on Galaxian; “Ode to Centipede”.
David Koon, “Centipede creator teaches at UALR”, Arkansas Times, 19 November 2015 (web, secondary): the joystick that clunked. https://arktimes.com/entertainment/ae-feature/2015/11/19/centipede-creator-teaches-at-ualr
Centipede program listing and documentation (Atari, 1980–81), published by historicalsource on GitHub, 15 October 2021: the programmers and start date, the copyright line, the hardware notes, Logg’s game documentation of 13 May 1981 (controls, scoring, enemies, languages, EAROM) and the release information of 11 May 1981. https://github.com/historicalsource/centipede
The Strong National Museum of Play, “Centipede”, World Video Game Hall of Fame (web, secondary): the 2020 induction. https://www.museumofplay.org/games/centipede/