Television Interface Adaptor
|Television Interface Adaptor|
1.) Pulse Wave or Noise
The Television Interface Adaptor (TIA) is the custom interface chip Atari designed for the Atari 2600 to display graphics, read joystick input, and produce sound. The chip's primary designer was Jay Miner who went on to design the main circuitry of the Atari 8-bit computers and the Amiga. In addition to plotting a game's graphics onto the screen, the TIA is also capable of producing two audio channels.
Each of the two channels can produce a pulse wave or noise. Each channel can be manipulated in frequency and volume.
Due to the numerous redesigns of Atari hardware, the TIA chip is located in different locations on various boards, and has different chip designations.
The TIA can produce variable PCM music by custom music engine, but it is even harder to do it than on another 8-bit platform like ZXS/A2/A8: currently only one game, Stella's Stocking (A26), has it (and it don't produce human voice). Here are some notes from the game's composer how it was created. The another way is AtariVox.
The TIA was originally designed for the 2600, but was later used in the 7800 for backward compatibility.
Pretty much every game released for the Atari 2600 or 7800 utilized the TIA.
Any Atari 2600 or 7800 emulator with sound capabilities emulates the TIA.