Atari PCS (8-bit Family)

Atari PCS Specifications

Lifespan

1984-1992

Media

Floppy disk, cassette tape, ROM cartridge

CPU 8-bit

MOS Technology 6502 @ 1.79 (NTSC) / 1.77 (PAL) MHz

Memory

16 - 128 KB dynamic RAM

Controllers

Joystick, mouse

Notable games

Rescue on Fractalus!, Pac-Man, Miner 2049er

Atari 800

History

The engineering team from Atari Grass Valley Research Center started work in 1977 on a successor to the just-released VCS. The new system would have a suite of custom chips – ANTIC to fetch data from RAM, CTIA/GTIA to convert the data into colors and overlay sprites (called player/missile graphics), and POKEY to read input devices and generate sound.

The system would be released in two forms, the Atari 400 (16 KB, membrane keyboard) and the Atari 800 (48 KB, two cartridge ports, composite output, full keyboard). FCC regulations forbid the use of slots, so peripherals had to be hooked up to the slow serial SIO bus.

The Atari 5200 game console used the same architecture, but the 800XL computer with 64 KB would prove to be the most popular model.

Memory Map (Atari 800)

Start

End

Description

Alternate Use

$0000

$00FF

RAM, zero-page

$0100

$01FF

RAM, CPU stack

$0200

$7FFF

RAM

$8000

$9FFF

RAM

Right Cartridge ROM

$A000

$BFFF

RAM

Left Cartridge ROM

$C000

$CFFF

RAM

$D000

$D01F

GTIA

$D200

$D20F

POKEY

$D300

$D303

PIA

$D400

$D40F

ANTIC

$D800

$FFFF

BIOS ROM

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