Bouncing Ball was an early interactive computer graphics program developed for the Whirlwind I computer at the Massachusetts Institute of Technology (MIT) in the early 1950s. Initially created as a physics demonstration simulating the motion of a bouncing ball, the program was later adapted into an interactive game in 1952 or early 1953 through the addition of a target hole in the floor of the display. Bouncing Ball is one of the earliest examples of animated computer graphics. It is one of two games known to have been developed for Whirlwind, alongside a blackjack program probably written between 1954 and 1959 (according to Guy Fedorkow).

Development

Page from the programming manual for Whirlwind I, featuring a description and illustration of the 'bouncing ball' program

The original bouncing-ball simulation was developed for the Whirlwind I computer, a pioneering real-time digital computer constructed at MIT for the U.S. Navy. Whirlwind I became operational in 1951 and was among the first computers capable of displaying real-time graphical output on a cathode-ray tube display.

Bouncing Ball worked as follows:

the ball appeared as a moving spot on the scope. It bounced from left to right. Its movement across the screen described the path of an object based on a mass, initial velocity, and coefficient of restitution named by the bounce program's differential equations. Whenever it encountered the positions that had been designated as the ground, a sound was produced.

The program was demonstrated to the public at an Open House Day in April, 1951, where the 'gravity' setting could be adjusted to show the trajectory of the bouncing ball on the Moon, on Earth, and on Jupiter. The program was first described in detail, with sample code, in the June 11 technical report Programming for Whirlwind I. MIT computer scientist Norman Taylor attributes the program to Charles Adams:

Charlie Adams, the original programmer, decided that we'd better go beyond static curves. And he invented what we call the Bouncing Ball Program, the solution of three differential equations.

Taylor dates this to 1949, by which time Whirlwind I Code had been developed, and the oscilloscope set-up was being tested. However, video game historian Alex Smith has shown that the earliest document mentioning Bouncing Ball (2 February 1951) credits a student, Oliver Aberth with the creation of the program.

Gameplay

The original Bouncing Ball program was merely a demonstration, and not a game. Some time after its creation, it was modified by Adams and John T. Gilmore to add a small hole at the bottom of the screen for the ball to fall through, and to allow the user to turn a knob to adjust the frequency of the bounces. This was a substantial change to the program, taking it from about 32 words in length to around 300. It is unknown when exactly this modification was done; it is likely to have been in 1952, but the first contemporaneous description of it was from February 1953. After the modification, the members of the lab treated this interactive demo as a game by challenging themselves to set the frequency perfectly to hit the small hole in the floor.

The film Making Electrons Count, believed to be from 1953, shows Bouncing Ball in action, with the commentator describing it as a simulation of the differential equations representing the motion of a ball.

Legacy

Bouncing Ball is one of the first computer programs in the early history of video games, and is the first known game incorporating graphics that updated in real time. It was contemporaneous with Christopher Strachey's Checkers (1952), Alexander S. Douglas created OXO (1952), and Stanley Gill's Sheep and Gates (1952), all of which were also early mainframe games using a visual display. According to media historian Carlin Wing, re-creating Bouncing Ball became a standard programming challenge in the 1950s. He claims that by 1958, they were ubiquitous enough to be included in instruction manuals for analog computers such as the Donner Model 30, and may have inspired William Higinbotham for his creation of Tennis for Two (1958), one of the first computer games created solely for entertainment. Spacewar! (1962) was created at MIT by computer scientists who had direct experience of coding their own bouncing ball programs.

See also

External links

  • (Bouncing Ball shown at 10:58)