Controlling electronics with the Commodore 64 user port - Part 2
Controlling electronics with the Commodore 64 user port - Part 3 with Arduino
Controlling electronics with the Commodore 64 user port - Part 1
Controlling electronics with the Commodore 64 user port - Part 4 of 4 with Arduino and LCD and OLED
C64 - Connecting devices safely to the user port - Arduino data transfer
C64 User Port - a trivial example
Commodore 64 Ports & Plugs - what are they all for?
Controlling The C64's User Port
Retro Game Coders - Chris Garrett and Maker Hacks
C64 userport, controlling 12 bits
Commodore 64 User Port to solenoid
Dorktronic Commodore 64 User Port GPIO & GPIOTracker Software
C64 Opto Isolation User Port to Ardiuno part 1
Reading C64 Joysticks and Analog Input - Commodore 64 Electronics Part 3
BigTrak meets Commodore 64...Again - User port Programming fun & this time with a Happy ending!
64 Commodore 64 Cartridges: Expansions, Interfaces, Utilities, Games
Zeus LT: A multi-function interface board for the Commodore 64
Commodore 64 WiFi - Creating a weather service
Arduino Project: Commodore 64 interfacing across the user port
Using A Commodore 64 To Control A Flashing Light
Why the Commodore 64 Mostly uses Joystick Port 2
C64 User-Port Expander - Build Up
Commodore 64 and HomeKit