C64 - Connecting devices safely to the user port - Arduino data transfer
C64 User Port - a trivial example
Controlling electronics with the Commodore 64 user port - Part 2
Commodore 64 Ports & Plugs - what are they all for?
Retro Game Coders - Chris Garrett and Maker Hacks
Commodore 64C repair Part 2 - dirty ports and keyboard sup...ports
DIY Commodore 64 Ultimate Userport Installation Guide
My C64 Ultimate just did a Peri Fractic!
C64 userport, controlling 12 bits
Maker Advent 2025 Day 24: Commodore 64 Ultimate User Port Breakout
Controlling electronics with the Commodore 64 user port - Part 1
C64 User-Port Expander - Build Up
C64 Hardware - WIC64 - Wifi user port modem
Arduino Project: Commodore 64 interfacing across the user port
C64 on trial: Is it any good as a serial terminal?
How a Character LCD Works - Part 2
Controlling The C64's User Port
Arduino Project: Part 2 of Commodore 64 interfacing across the user port
PLATOTerm on real user port c64 hardware.
C64 Opto Isolation User Port to Ardiuno part 1
