The oddly named protection device called a DONGLE was plugged into the Commodore’s tape port or the joystick ports. When the program would load it would check for this Dongle, if it was there the program would load, if not the program would not.

Here a list of Commodore software that I know used a Dongle as it’s form of copy protection.

10th Frame: used the dongle on the tape port
Coco
Coco 2
Insta-Calc (some version)
Leaderboard
Leaderboard World Class
Neutral Zone
Paper Clip’s dongle fits into the Joyport,