The Atari 400 Computer Home Console contains the central processor unit (CPU) and memory in the form of the Operating System (read-only-memory (ROM)) and 8K or 16K of user programmable random access memory (RAM). The console contains the keyboard, cartridge slot, controller jacks, and serial input/output (I/O) port for connecting peripheral devices (see Figure 1-1).

The ATARI 800 Home Computer Console contains the CPU and memory In the form of the Operating System (10K of read-only-memory (ROM)) and 8K to 16K (standard) of user programmable random access memory (RAM); plus two expansion sockets for additional RAM modules (maximum 48K). The console also contains the keyboard, cartridge slots (2), controller jacks and a serial I/O port for connecting peripheral devices (see Figure 1-2).