What keyboards do I need for these vintage PCs?

I picked up two old PCs that I want to test and, eventually, sell. Will need to buy keyboards for them, so trying to figure out the exact specs.

The 1st one seems to need some sort of 9-pin com keyboard. I read up a bit on vintage connectors but got confused by the alphabet soup of different types. What does this one need? And are there adapters that would allow me to connect a PS2 or a USB keyboard to it?

The 2nd one needs a kb with a round plug (sorry for the bad angle in the photo). What's the exact type? Again, are there adapters for those?

Thanks!

both computers take the old 5 pin din plugs like the one pictured from my ebay auction here IBM 5160 PC XT Model F Keyboard Tested and Working | eBay I have a few of these old keyboards. They do make an adapter and I did have one around my shop but not sure where it is right now.

there were 3 major connector of keyboards....obviously the newer USB and 6 pin mini DIN (ps/2) are the most familiar. The older ones used a 5 pin DIN (also called an AT connector)....there are adapters out there for all of these...so you could take a PS/2 keyboard and get an adapter for an AT connection. Far cheaper than finding an old vintage keyboard.

Remember, especially old AT keyboards...the mechanical keyboards (they have a difference clicky sound) sell for $$$. PEople STILL love them over regular keyboards in many instances and pay a premium even for modern versions...ALWAYS check the model number before tearing them apart.