Battlezone put the player inside a tank. Through a viewer on the front of the cabinet, early players looked out on a battlefield drawn in thin lines of light: a plain that Electronic Games placed on the Moon, a crescent Earth in the sky, a volcano on the horizon and enemy tanks hunting them. The player drove with two sticks, one for each track, and could go anywhere. Atari released it in 1980, and its designer, Ed Rotberg, knew what he had as soon as he could drive around the playfield: “no one had ever done anything like this.”
The US Army noticed too, and the game’s most unusual descendant was a trainer for the Bradley fighting vehicle, built by a programmer who did not want to build it.
Fast facts
- Maker: Atari, coin-op division, 1980.
- Program: Ed Rotberg; project leader Morgan Hoff. Howard Delman built the vector hardware, Jed Margolin helped with the 3D maths and Owen Rubin wrote the erupting volcano.
- Display: a vector monitor, Atari’s QuadraScan, with the 3D sums done by a separate “Math Box” processor.
- Controls: two sticks, one for each of the tank’s tracks.
- Cabinet: early machines had a periscope viewer, later dropped.
- Production: about 15,000 machines, according to The Atari Book.
- Home versions: Atari 2600 (1983) and the Commodore VIC-20, among others.
- Source code: published on GitHub by the historicalsource archive in October 2021, with no licence stated.
Into the third dimension
Rotberg joined Atari from Chicago in 1978. At the University of Michigan he had taken a computer graphics course taught by Jim Blinn, then a graduate student, who “taught me my first 3D stuff”. When Atari’s vector displays arrived, he said, “we had the means to do something more than blocky pixels.” Atari set two teams on 3D vector games. The rival team got Red Baron on screen first, but Rotberg’s tank game, at first called Future Tank and then renamed Battlezone, reached the market first.
The project file, started on 25 April 1979, describes the idea in one line: “1st person view of traditional Atari tank game”. “The inspiration came from those early overhead-view tank games, which everyone loved,” Rotberg said; Battlezone dropped the player into the battlefield instead of looking down on it. The same header lists the hardware it needed: vector hardware with “Delman’s auto-normalization” and a “matrix math module (initially Lunar Lander)”.
That module did the heavy arithmetic. Every object had to be rotated and projected onto the screen each frame, and the game’s 6502 processor handed those sums to extra hardware. Atari’s “Math Box” was built from AMD 2901 four-bit slices, joined into a 16-bit unit that multiplied and divided on command. Rotberg’s approach began, as always, with the data: “I knew we needed stationary objects that would have to be described, and since resources were precious, the objects had to be instanced.” The same few shapes were placed again and again at different sizes. Fixed-point arithmetic built up errors that could make everything distort, and the engineer Jed Margolin found a way to keep them down.
Everything on screen was a trade against the number of lines the vector generator could draw and the sums the game could finish in a frame. The mountains were cheap, because they were only a backdrop. The volcano was not in the plan: Owen Rubin kept asking when it would erupt, Rotberg told him to program it himself, and the code was on Rotberg’s chair the next morning. The source still says “VOLCANO STUFF – SEE RUBIN”.
Rotberg was careful about the claim to be first. Tim Skelly’s Tail Gunner (1979) came earlier, but “was on-rails and there was no environment, just stars”. Battlezone, he said, was “3D in a 2D world”: the player could not move up or down, but “the graphics were truly three-dimensional.” The vector graphics entry places it among the QuadraScan games, and Tempest followed it into 3D in 1981.
Playing it
A radar in the middle of the screen showed where the enemies were, which Rotberg called a necessity: “Put someone in our 3D world and they can’t turn their head — only ponderously turn the tank.” The first enemy was a standard tank, “the learning level, where you figure out how to shoot”. Then came a flying saucer worth many points, which distracted the player from the tank that could kill them; a tougher super tank; and a missile, the only thing apart from explosion debris that moved up and down. It zigzagged towards the player, and Rotberg liked the “Zen-like quality” of learning when it would turn.
Players wrote in claiming their friends had reached the volcano, or found a tank factory. They had not. The background was “strictly a background”, and the playfield wrapped around: “16-bits in either direction and you were back at zero!”
In August 1982 it stood sixth in the readers’ poll of coin-op games in Electronic Games, and the magazine recorded a score of 5,899,000 by Mike Johnston of Los Alamitos, California, set on 26 March 1982 over seven hours and a quarter.
The periscope
The two sticks came from the tank itself: “a tank’s got two treads and that’s how they turn.” Budget limits gave each tread one speed, which made the controls easy to learn. The periscope was Morgan Hoff’s idea. Rotberg opposed it, because only the player could see the game, and he worried that a game nobody could watch would earn less. Atari added clear side panels, then dropped the viewer. Electronic Games gave Battlezone an honourable mention in its 1982 awards and explained that “Atari deep-sixed the periscope when the company realized that people enjoy watching the hunt for the enemy vehicles almost as much as taking the controls themselves.” It still thought the original had “a special flavor, putting the player in splendid isolation even in the middle of a crowded amusement center.” The monitor lay on its back in the cabinet, the magazine noted, reflecting its picture off a slanted, half-reflective surface.
The Bradley Trainer
The Army’s interest was public early. In December 1981 Electronic Games reported that Captain Gary Bishop at Fort Stewart, Georgia, was “studying the feasibility of using Atari’s Battlezone as a tank training simulator”.
Rotberg’s account of what followed, given to Retro Gamer in 2007 and to The Atari Book, is that a group of retired generals saw the game and asked for a trainer for one of their vehicles, and that Atari’s Rick Moncrief promised them a prototype quickly. Nobody else knew the code. “I’m a bit of a pacifist, so I didn’t really want to help train people to kill,” Rotberg said. He agreed on condition that he would have nothing more to do with it once it was done, and spent three months working 18-hour days on it. The trainer was aimed at the Bradley Infantry Fighting Vehicle. It added a machine gun, armour-piercing and incendiary shells, a TOW missile the gunner had to keep on target after firing, and x3 and x12 magnification, and it was meant to teach the silhouettes of friendly and enemy vehicles. Howard Scott Warshaw, who also worked at Atari, remembered it the same way in Wireframe in 2020: the Army “commissioned the makers of Battlezone to create a higher-end version, later known as the Bradley Trainer”.
The Atari Book says Atari decided military work was not a business it wanted, and did not take it further. Some good came of it anyway. The new controller went into Atari’s later games, starting with Star Wars, which grew from a project of Rotberg’s that took the Army controls into space.
After the arcade
Rotberg left Atari with Howard Delman and Roger Hector to start their own company, Videa; Video Games Player reported the move in September 1982, calling them “the three guys responsible for Atari’s Battlezone”. Home versions arrived later, and could not copy the original. “It was like paraphrasing,” Rotberg said. “There’s no way these games could quote Battlezone, but they could paraphrase it.” The Atari 2600 cartridge, advertised in December 1983, swapped vectors for fast raster graphics, with enemy fighters among the targets. The VIC-20 version kept more of the look but gave up speed and resolution. Atarisoft advertised Battlezone among its games for other companies’ computers in 1984, and British players met many imitations, such as Jon Ritman’s 3D Combat Zone for the Spectrum.
The name returned twice. Activision’s Battlezone of 1998, for the PC, mixed a tank game with real-time strategy; its advertisements recalled that “In 1980, Battlezone introduced true 3-D graphics.” The British developer Rebellion then made a new Battlezone for Sony’s PlayStation VR headset, released as a launch game on 13 October 2016.
The source code
The historicalsource archive published the arcade program’s files on GitHub in October 2021, without a stated licence. They include the game’s 6502 source, its sound and self-test modules, and the documentation for the Math Box. The project document, dated 31 August 1981, names Edward Rotberg as project programmer and Morgan Hoff as project leader.
Sources
- Craig Grannell, “The Making of Battlezone”, The Atari Book (Retro Gamer, 2012), pp. 144–147: the overhead-view tank games, Delman’s vector generator, “no one had ever done anything like this”, Tail Gunner, instanced objects, Jed Margolin, the volcano and Owen Rubin, the radar, the enemies and the missile, the two-stick controls, the viewfinder, about 15,000 units, the Bradley Trainer and Rick Moncrief, the controller used in Star Wars, the VIC-20 and VCS conversions and “paraphrasing”, the playfield wrapping round.
- Paul Drury, “Desert Island Disks: Ed Rotberg”, Retro Gamer issue 39, 2007, pp. 84–86 and 88: joining Atari in 1978, Jim Blinn, the bit-slice processors, Future Tank and Red Baron, “3D in a 2D world”, the periscope in 1980 and the hidden cave, the “crescent earth” (caption, p. 86), the Army trainer and its weapons, “a bit of a pacifist”, three months of 18-hour days, Warp Speed and Star Wars, Videa; the periscope as Morgan Hoff’s idea (p. 88).
- Electronic Games, vol. 1 no. 1, December 1981, p. 71: “an sf tank battle on the moon”, the cabinet’s reflected monitor; p. 73: Captain Gary Bishop and Fort Stewart.
- Electronic Games, vol. 1 no. 2, March 1982, p. 49: Arcade Awards honourable mention and the periscope.
- Electronic Games, vol. 1 no. 6, August 1982, p. 11: readers’ coin-op chart; p. 12: the 5,899,000 record.
- Video Games Player, vol. 1 no. 1, September 1982: Delman, Rotberg and Hector leave to form Videa.
- Video Games, vol. 2 no. 3, December 1983, p. 7: Atari’s advertisement for the 2600 cartridge.
- Family Computing, vol. 2 no. 9, September 1984, p. 119: Atarisoft advertisement listing Battlezone.
- Howard Scott Warshaw, “The principles of game design”, Wireframe issue 42, August 2020, p. 46: the Army and the Bradley Trainer.
- Activision advertisement for Battlezone, PC Gamer (UK) issue 53, February 1998, p. 2.
- Jason Kingsley, “5 Things You Didn’t Know About Battlezone on PS VR”, PlayStation Blog, 25 August 2016 (web, secondary): Rebellion’s game and its release on 13 October 2016. https://blog.playstation.com/2016/08/25/5-things-you-didnt-know-about-battlezone-on-ps-vr/
- Battlezone program files (Atari, 1979–81), historicalsource/battlezone on GitHub, published October 2021, no licence stated: the BZONE.MAC header, the volcano comment, the Math Box documentation (AMD 2901 slices), the project document of 31 August 1981. https://github.com/historicalsource/battlezone