Joystick

The Radio Shack CoCo joystick was the standard joystick sold for the CoCo by Radio Shack. Nearly all CoCo games and other applications were compatible with it.

Like the iconic Atari 2600 joystick, it was black with a single red action button, but it had substantial differences.

The RadioShack CoCo joystick was a black trapezoidal box, sized and meant to have its bottom face resting in the palm of an upturned hand. It had a single red fire/action button in the front face meant to be pressed with the holding hand's index finger, and which had a distinct click or snap when engaged.

The stick itself was thin and short, designed to be gripped with the fingers of the other hand like a pencil or chopstick. At first the stick was metal; later versions were of the same black plastic as the rest of the device and were more susceptible to being bent in place or snapped. It was relatively small and delicate because it was analog rather than digital, enabling finely detailed control.

An analog joystick is a joystick which has continuous states, i.e. returns an angle measure of the movement in any direction in the plane or the space (usually utilizing potentiometers). By contrast, a a digital joystick, such as the Atari 2600 joystick, gives only on/off signals for four different directions, and mechanically possible combinations (such as up-right, down-left, &c.).

Thus the CoCo joystick was, in a sense, a trackball or upside-down mouse with a stick attached to the ball. With it, one could draw loops around objects in DoubleBack or quickly fling the trampoline holders across the screen in Clowns and Balloons.