Atari's answer to the Apple II was a pair of computers with graphics and sound above anything else at the time. They were very successful until the Commodore 64 showed up.
They were the first home computers to use custom coprocessors. Jay Miner, who designed the Atari 2600's TIA, headed up the design team for three new chips: CTIA (sprites), ANTIC (text and graphics) and POKEY (sound and I/O). [...] [tvtropes.org]