Korg PS 3 / PS 1 Single Momentary Pedal Footswitch for MIDI Keyboard, Synthesizers, Tone Modules, and Drum Machines|Guitar Parts & Accessories| - AliExpress
PSX Keyboard and Mouse Adaptor (SCPH-2000 Prototype) - Page 3 - PlayStation Development Network
Korg PS-1 Single Momentary Footswitch PS1 B&H Photo Video
Original IBM PC AT Keyboard, Thoroughly Cleaned and ANSI Modified with Soarer's Converter – Brand New Model F Keyboards
Original IBM PC AT Keyboard, Thoroughly Cleaned and ANSI Modified with Soarer's Converter – Brand New Model F Keyboards
Keyboard Adapter PS/2 Keyboard to PS1 Untested - Etsy
Playstation: Generations : r/MechanicalKeyboards
IBM PS1 2121 - Gallery - MCbx
Here's a prototype keyboard adapter for the PS1. It was intended to be used with the planned modem. Sony did create an official version without the cord, but was never released. :
Kensington K64406us Washable Usb/ps2 Keyboard - Usb, Ps/2 - 104 Keys - White - English (us) : Target
Fellows PS/2 Wired Keyboard Multi Function 4 Internet 7 Multimedia 3 Power Keys 77511594946 | eBay