Joysticks
People started developing interfaces to connect joysticks to their TRS-80 soon after it was introduced. One common approach was to solder an Atari joystick (the de-facto standard at the time) directly to the TRS-80 keyboard. This technique was described in detail in an article from Creative Computing. But the most popular joystick interface was created by Alpha Products. Other products supported and enhanced this standard, and most TRS-80 games supported it.
The Stickeroo Joystick Interface
