Atari · Atari 2600 · 1977
The Atari CX40 joystick shipped with the Atari 2600 in 1977 and became the most widely recognised game controller of its era, shaping how an entire generation learned to interact with games before d-pads existed.
The CX40 was a single-button joystick with an eight-directional stick and a large orange action button on the base, designed for use with one hand — the stick operated by the fingers and the button pressed by the thumb or heel of the palm. Its black rubber boot and orange components were visually distinctive and functionally durable: the joystick mechanism could absorb the rough treatment of children playing arcade conversions for thousands of hours without failure. The 9-pin DE-9 connector the CX40 used became an industry standard adopted by Commodore 64, Amiga, Atari computers, Sega Master System, and Sega Genesis in the same port, making the CX40 and its clones compatible with an extraordinary range of hardware across fifteen years of personal computing. Atari sold millions of CX40s as both pack-in and replacement controllers, and third-party manufacturers produced hundreds of variants, making it the most cloned controller design in the pre-d-pad era.
Establishing the DE-9 joystick port as an industry standard used across multiple manufacturers and platforms for nearly two decades.
The CX40's design reflected the constraints of 1977 arcade and home game software. Pong and its derivatives required only a vertical axis; early Atari 2600 games introduced lateral movement and a single fire action, which the CX40's stick-plus-button arrangement covered completely. The stick mechanism used a simple four-switch arrangement — microswitches at each cardinal direction — with the diagonal positions activated by pressing between two switches simultaneously. This produced consistent, tactile input with a satisfying click at each direction boundary, though the mechanical nature of the switches meant that diagonal precision depended on the player's ability to press precisely between adjacent positions.
Atari's decision to use the 9-pin DE-9 connector — chosen because it was already a common industrial standard — had consequences far beyond the 2600. When Commodore designed the VIC-20 and C64 joystick ports, they adopted the same pinout for compatibility. Atari's own 8-bit computers used identical ports. When Sega designed the Master System controller, they adopted the DE-9 standard. The result was that a CX40 joystick purchased in 1977 would work without modification on a Sega Genesis purchased in 1989 — a span of hardware compatibility unprecedented in consumer electronics.
The CX40's rubber boot — the flexible sleeve covering the stick mechanism — was simultaneously the controller's most distinctive visual feature and its primary failure point. Prolonged heavy use caused the boot to crack and eventually split, exposing the plastic mechanism underneath. Replacement boots were commercially available and widely sold, suggesting that owners valued the controller enough to repair it rather than replace it. The internal microswitch mechanism was substantially more durable than the boot and typically outlasted multiple replacements.
The single button was a significant limitation as game software grew more complex in the early 1980s. Games requiring multiple simultaneous actions — Decathlon's button mashing, Activision titles with fire and secondary actions — stretched the one-button design to its logical limit. Third-party manufacturers responded with multi-button replacements like the Wico Command Control and various bat-top arcade sticks that improved precision for games demanding quick directional changes. By 1983, the limitations of the CX40's single-button design were apparent to developers; the d-pad's two-button companion arrangement on the NES controller directly addressed the gap the Atari design had exposed.