Television Interface Adaptor
The Atari TIA ( stands for Television Interface Adapter ) is a custom chip of the Atari company and is the central GPU for the game console Atari 2600. The chip was designed by Jay Miner, who would later mitgründen the company Amiga.
The chip is responsible for creation of the television picture and an access for the control of the hardware and for displaying the game images. Thus, the chip could be produced particularly cost-effective, the TIA has no video RAM for storing the graphics, but generates each image line individually. The data for this come from registers for the background color, some registers that can be shown repeatedly represent half a line and from the middle of the screen either mirrored or as well as five special graphics objects:
- Two 8- pixel lines, which were the sprites player 1 and player 2. These pictures could always be shown only in one color and the size of the sprites could be stretched by a factor of 2 or 4.
- Two Sprites ' Missiles ' - A line that is the same color as the player had. These sprites could be one, two, four or eight pixels wide.
Furthermore, the TIA can read and also send the collision behavior of the individual objects. The registers of the TIA allow the programmer to the position of the graphical objects and to define their color. The TIA is also responsible to provide two channels of sounds available. Finally, the TIA is responsible for the input query: It can detect and process signals from digital and analog joysticks paddles.
The programming of the TIA turns out to be a very difficult task represents the limitations of the processor could make the implementation of certain game ideas a big challenge. Today, these limitations are however a number of amateur programmers who continue to develop games for the Atari 2600, an interesting challenge considered.
Atari expanded in the following years, the design of the TIA for the home computer Atari 400 and Atari 800 with the Color Television Interface Adaptor.