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/* Hardware */
In addition to its 1.79 Mhz [[MOS 6502|6502]] CPU, the Atari computer offloads some of the work to its specialized chips: ANTIC, CTIA & POKEY.
POKEY (POt KEYboard integrated circuit) is a digital Input/Output chip. It handles such disparate tasks as the SIO bus and its peripherals, audio generation, keyboard scan, and random number generation. It also digitizes the resistive paddle inputs and controls maskable interrupt (IRQ) requests from peripherals.
ANTIC and CTIA together produce the graphics, up to a resolution of 320x192 pixels, sprites, scrolling in any direction, different graphic modes that can be mixed on the same screen, etc.
When launched in the US, the Atari 400 & 800 came with a CTIA (Color Television Interface Adapter) chip, which offered 9 graphic and text modes (GR.0-8) in Atari BASIC and a 128-colour palette. In early 1982, CTIA was replaced by GTIA (Graphic Television Interface Adapter), which provided 3 additional graphics modes (GR.9-10-11) in Atari BASIC, with a 256-colour palette. The GTIA chip equipped all new Atari 400 & 800, and their successors.
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