Here we get a close-up look at the CPU card. The Atari 800 uses an 8-bit Synertek 6502B microprocessor, a variant of the famous and prolific MOS 6502.
You might notice a sticker labeled 'GTIA 1/16/86'. That's the date when my father upgraded our Atari 800's television adapter chip--the CTIA--to the improved and revised GTIA. To the left of that sticker is the ANTIC chip, which works with the CTIA/GTIA to create the Atari 800's impressive graphics. The 800 also contains a custom sound chip--POKEY--that provided excellent music-reproduction capabilities for 1979. Overall, the biggest advantage that the Atari 800 had over its competitors was its powerful custom chipset, though that wasn't enough to guarantee Atari a prime spot in the personal computer market.