Atari 2600 Hardware - Technical Specifications

Technical Specifications

• CPU: 1.19 MHz MOS Technology 6507
• Audio + Video processor: TIA
  • Playfield resolution: 40 x 192 pixels (NTSC). Uses a 20-pixel register that is mirrored or copied, left side to right side, to achieve the width of 40 pixels.
  • Player sprites: 8 x 192 pixels (NTSC). Player, ball, and missile sprites use pixels that are 1/4 the width of playfield pixels (unless stretched).
  • Ball and missile sprites: 1 x 192 pixels (NTSC).
  • Maximum resolution: 160 x 192 pixels (NTSC). Max resolution is only somewhat achievable with programming tricks that combine sprite pixels with playfield pixels.
  • 128 colors (NTSC). 128 possible on screen. Max of 4 per line: background, playfield, player0 sprite, and player1 sprite. Palette switching between lines is common. Palette switching mid line is possible but not common due to resource limitations.
  • 2 channels of 1-bit monaural sound with 4-bit volume control.
• RAM (within a MOS Technology RIOT chip): 128 bytes (additional RAM may be included in the game cartridges)
• ROM (game cartridges): 4 kb maximum capacity (32 kb+ with bank switching)
• Input (controlled by MOS RIOT):
  • Two screwless DE-9 controller ports, for single-button joysticks, paddles, "trakballs", "driving controllers", 12-key "keyboard controllers" (0–9, #, and *) and third party controllers with additional functions
  • Six switches (original version): Power on/off, TV signal (B/W or Color), Difficulty for each player (called A and B), Select, and Reset. Except for the power switch, games could (and did) assign other meanings to the switches. On later models the difficulty switches were miniaturized and moved to the back of the unit.
• Output: B/W or Color TV picture and sound signal through RCA connector (NTSC, PAL or SECAM, depending on region; game cartridges are exchangeable between NTSC and PAL/SECAM machines, but this will result in wrong or missing colors and often a rolling picture.)