IBM PS/1 Type: 2011-C34 w/ Model M2 IBM Clicky Keyboard & IBM proprinter 24 | #1794749935
Kensington Pro Fit Washable USB & PS/2 Keyboard - Black | Dell USA
PlayStation Mouse - Wikipedia
OLD-COMPUTERS.COM Museum ~ IBM PS/1
PSX Keyboard and Mouse Adaptor (SCPH-2000 Prototype) - PlayStation Development Network
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. :
Prototype of keyboard/mouse adaptor for PlayStation - Prototypes - AtariAge Forums
Amazon.com: Perixx PERIBOARD-409P Wired PS2 Mini Keyboard, Black, US English Layout : Electronics
PERIBOARD-107 PS/2 Full Size Retro Keyboard High Profile Ergonomic Keys – Perixx USA
Original IBM PC AT Keyboard, Thoroughly Cleaned and ANSI Modified with Soarer's Converter – Brand New Model F Keyboards
Amazon.com: KORG PS-1 Single Momentary Pedal Footswitch for MIDI Keyboard : Musical Instruments
Microsoft Keyboard - PS/2 Model RT9410 - VINTAGE TESTED WORKING 659556131197 | eBay
Vintage IBM KB-9930 PS/2 Keyboard – Recycling Angel
PS/2 Keyboard to USB Adapter - F/M - PS/2 Cables | StarTech.com
PS/2 to AT IBM Keyboard Adapter Cable - PS/2 Cables | StarTech.com
PlayStation Classic mod yields frame rate improvements, scanline options, and more | GamesRadar+
Logitech USB Keyboard for PlayStation 2 for sale online | eBay
Korg PS 3 / PS 1 Single Momentary Pedal Footswitch for MIDI Keyboard, Synthesizers, Tone Modules, and Drum Machines|Guitar Parts & Accessories| - AliExpress
Kensington K64406us Washable Usb/ps2 Keyboard - Usb, Ps/2 - 104 Keys - White - English (us) : Target