commodore 64 - Would a multi button controller have been possible on the C64? - Retrocomputing Stack Exchange
Retro Isle - C64/128 Technical Section
C-64 Workshop / Pin Connections
DIY) USER PORT DONGLE for C64 586220 DIAGNOSTIC CARTRIDGE - Share Project - PCBWay
Vectrex Controller to Atari 2600 Adapter - CNK
Technical corner
C64 DB9 compatibility | Official Pyra and Pandora Site
Joystick C64 vs Joypad NES – Retro Fixer
Retro Joystick CPC Adapter
Connectors Commodore 16 – My old computer
Tube Time on Twitter: "the left one is a Commodore 1351 mouse designed for a C64/C128, while the right one is meant for an Amiga. the pinouts are very close and neither
Connectors Commodore 64 – My old computer
9 Pin Joystick to USB Adapter
Joystick interface for C-16, C-116 and Plus/4 - V1.1
Joystick information and circuits
ESD Protection for the C64 Control Ports | hackup.net
Connectors Commodore SX 64 – My old computer
The Keypad Joypad - Amiga, Atari, C64... | Hackaday.io
Control Port - C64-Wiki
Obsolescence Guaranteed: Converting the 'Commodore 64' DTV
General Purpose port - MSX Wiki
Reading C64 Joysticks and Analog Signals (Programming Electronics with the Commodore 64 Part 3) - Retro Game Coders
Making a Joystick for C64 or Atari | Kosciusko Media
How to connect old Atari style joystick to bluetooth PCB? - Electrical Engineering Stack Exchange
