USB PS2 Mouse Adapter -> Atari ST Amiga Amstrad Commodore 9pin DB9 Joystick Port | eBay
Joystick wiring help - English Amiga Board
9pin Joystick Controller Cable for Atari 2600 Commodore C64 Vic-20 Ami – RetroArcadeCrafts
Sinclair Spectrum 128+2 / 128+3 Joystick Adapter - 1 port version
digital joystick adapter for the PC
pagetable@mastodon.social on X: "[UPDATE] Converting the “Competition Pro Extra USB” to C64/Amiga/Atari DB9 https://t.co/V7GpznRbNr The post now includes the new “V1.2” pinout and was updated with the use of a joystick extension
Arduino Project: Commodore 64/Amiga, Atari 2600/XL/ST, ZX Spectrum Joystick to Windows/Linux (RetroPie) USB | jfrmilner's Tech Blog
Converting the “Competition Pro Extra USB” to C64/Amiga/Atari DB9 – pagetable.com
Retro Isle - C64/128 Technical Section
Joystick interface for C-16, C-116 and Plus/4 - V1.1