The Atari 2600 was launched in 1977 as the Atari Video Computer System or Atari VCS. In 1982 the name was dropped in favor of just Atari 2600.

The console was a huge success, and an innovation of its time. It used a microprocessor and a cartridge slot to run different games that were burned into ROM chips on the cartridge. This format was first used by the Fairchild Channel F system in 1976.

When the Atari VCS launched, the ROM cartridges were 2KB in size, and the games were rather simple and low-resolution. The conversion of Taito's Space Invaders pushed the system to the masses. The VCS became hugely popular and lead to the founding of game developers like Activision and others. Later cartridges were using much more advanced graphics and used 8KByte ROMs.

The Atari heavy sixer is the earliest version of the Atari 2600 game console. It is more valuable to collectors than the later version of the system, as it is widely considered the original 2600.

The heavy sixer gets it's name from the fact that it has six pull-down style switches along the top of the unit, and a plastic case, that has a very thick edge. The case itself weighs more than 500 grams.

In later versions, first the case was re-designed to be lighter and cheaper, and after that the two difficulty switches (for left and right difficulty) were moved to the back of the unit, as most games did not utilize these.

The Atari 2600 came with a joystick that was especially designed for the unit. It is a four-directional joystick, with eight inferred directions. It was equipped with a single trigger button.

The joystick is digital and uses a 9-pin DIN sub miniature connector, that became standard on many home computers to come. Brands such as Commodore, Master System, Genesis and to some extent MSX, were compatible, and you could use the joystick on those systems as well.

Despite being outdated, and not the most ergonomic joystick, the atari 2600 stick has become a symbol of early video games and is often used to brand retro game merchandise.

The first Atari 2600 Stella Prototype is on display in the Computer History Museum, which is located in Mountain View california.

The Atari Player-Missile Graphics (PMG) system was not a framebuffer in the modern sense but a set of time-critical shift registers built directly into the TIA (Television Interface Adapter) chip. It provided five independent movable objects: two "players," two "missiles," and one "ball." Each player was an 8-bit wide pattern register that could be shifted horizontally by writing to horizontal motion registers, and the missiles were single-bit wide objects with optional width expansion (2× or 4×). The ball was also a single-bit wide object but could be stretched up to 8 pixels. These objects were rendered in hardware in parallel with the background playfield, and their pixels were combined by priority logic to form the final composite video signal line by line. Unlike bitmap systems, no RAM buffer existed for sprite graphics—the CPU had to continually update the pattern registers at precise cycle counts if animation or varied shapes were required.

Synchronization with the television raster was crucial. The 6507 CPU executed instructions at 1.19 MHz, and each NTSC scanline consumed 76 CPU cycles. Developers had to time updates to the TIA registers so that the correct player/missile graphics appeared at the right horizontal positions. Horizontal positioning itself used a mechanism called "HMOVE," where writes to motion registers triggered a fine shift of the object relative to the color clock. To display more than two players per line, programmers resorted to "racing the beam," rewriting the player graphics mid-scanline or between scanlines to reuse the same hardware objects multiple times. This demanded cycle-accurate programming, often with unrolled loops or carefully aligned instruction sequences, to ensure that TIA updates coincided exactly with the raster beam.

The PMG system’s integration with collision detection further defined gameplay mechanics. The TIA contained hardware latches that reported collisions between any combination of players, missiles, the ball, and the playfield. Reading the collision registers gave the CPU instantaneous results without requiring software-based pixel overlap tests. This allowed real-time detection of events like a missile hitting a player, which was essential given the limited CPU resources. However, the narrow data path—1-bit missiles and balls, 8-bit players—and absence of automatic buffering imposed strict design constraints. Game graphics relied heavily on flicker techniques, multiplexing, and creative use of repeated patterns. Thus, the Atari PMG system exemplifies a minimal but highly deterministic hardware sprite engine, optimized for cost, that forced programmers to directly master scanline timing and low-level hardware interaction.

The MOS Technology 6507 CPU is an 8-bit microprocessor based on the 6502 technology. Basically it is a 6502 packaged in a 28-pin DIP instead of a 40-pin. This made the chip cheaper to package and integrate in systems. MOS technology achieved this by reducing the address bus from 16 bits to 13 bits and removing a number of other pins used only for certain applications.

The 6507 is the main chip of the Atari-2600 family of consoles. The Chip was launched in 1975 and could, due to the reduced number of address pins, address 8KByte of memory. This proved to be enough for the Atari consoles and for peripherals such as the 850 Serial & Parallel Interface, the 1050 disk drives and more.