Reddit reviews 5-Pin DIN-Male AT to 6-Pin Mini DIN-Female PS/2 Keyboard Adapter PS2 KB-ATM-PS2F-6I

Alright. Here's the deal.

https://imgur.com/a/fLPcC

Point 1: This is an old AT DIN keyboard connector. It is physically compatible with PS/2 keyboards. You can get adapters to connect to any PS/2 keyboard. You could also connect to some sort of active USB to PS/2 converter, but it's much, much easier to just find an old PS/2 keyboard.

I mean, you could find a really old AT keyboard with the right plug on it and use that, but it's much easier to just get a PS/2 keyboard.

Point 2: This is a PS/2 port. Use a PS/2 mouse or one of those little green USB to PS/2 mouse adapters.
You cannot plug a keyboard into this.

The 25 pin connector should not be touched. It's likely serial (just from its position beside a PS/2 connector), which technically could be used for a mouse, but you have a PS/2 connector, so why would you? It also may be parallel, too. in any case, you have PS/2. Don't touch it.

Tada!

You're going to need a 5 pin DIN to PS/2 adapter, a PS/2 keyboard and a serial to ps/2 adapter with a PS/2 mouse.

Looks like you have a CD drive so you'll probably want to install a very light weight linux like Tiny Core Linux

You will need one of these 5-PIN DIN male to PS2 female https://www.amazon.com/DIN-Male-DIN-Female-Keyboard-Adapter-KB-ATM-PS2F-6I/dp/B001P73TE6 and a ps2 keyboard.