Ballpoint pen and joystick: what they have in common

1. Step 1. Ballpoint pen — uses — Ink. Thick oil-based ink.
2. Step 2. Ink — is used in — Printer. It prints with ink.
3. Step 3. Printer — has part — Microcontroller. A controller processes the print job.
4. Step 4. Microcontroller — is part of — Gamepad. A microcontroller polls the buttons.
5. Step 5. Gamepad — evolved from — Joystick. A game controller.

Open Evothings