The March 1981 Alpha Products advertisement featured the first appearance of the DOUBLE-STICK-80. This package included two joysticks, interface, and demo game for $59.95. The second joystick was mapped to the same port as the first, but it used the upper four bits instead of the lower four. The DOUBLE-STICK-80 sounds like an interesting idea, but I have never found a program that was designed to use it. The DOUBLE-STICK-80 was no longer mentioned in advertisements just a few months later.