Timeline of significant dates in the production of video games (selected).
1958: Physicist Willy Higinbotham invents the first "video game" at the Brookhaven National Laboratory in Upton, New York. His game, a table tennis-like game, was played on an oscilloscope.
1966: Ralph Baer, an engineer at Sanders Associates, receives support from his company (a military electronics consulting firm in NH) to explore his idea of creating interactive games using a television.
1967: Baer and team are successful in creating two interactive TV games—a chase game and a tennis game. They are also able to manipulate a toy gun so that it detects spots of light on the TV screen.
1970: Computer Space becomes first video arcade game ever released. 1500 games are distributed. Public consensus is that it is too difficult to play.
1972: Magnavox's Odyssey, the first home video game system, is showcased at a convention in Burlingame, CA, and is released to the public later that year.
1978: Midway introduces Space Invaders into arcades. It is the first arcade game that tracks and displays high scores.
1979: Asteroids is the first game to allow high scorers to enter three character initials to be stored in the machine.
Source: Infoplease , Ralphbaer.com
An abbreviated history of Internet graphics.
1884: Nipkow (Germany) devises scanner for scanning and transmitting images.
1970: Lilian Schwartz produces 'Pixellation'
1987: GIF and JPEG formats developed.
Source: History of internet graphics
If I can merge this timeline with the Teletext and an abbreviated Internet one then select the most significant, there should be enough content for an overall timeline. Fingers crossed for that.