by Bret » Mon Feb 14, 2022 5:45 am
I don't thing you're going to find such a device anywhere. USB is a master-slave (host-device) arrangement with the computer (normally) being the master and the various other devices (including keyboards) being the slaves. A host is supposed to be able handle dozens of devices all sharing the same bus, but in your case you would only want one (a keyboard). What you're wanting is a USB host inside a small device that only supports one external device (a keyboard) and outputs a virtual PS2 keyboard (a relatively simple serial connection) on the PS2 port. I seriously doubt anybody is going to produce such an item off-the-shelf since there simply is no market for such things. It's conceivable somebody has made such a device as a "hobby" project, but it would have just been an experiment simply to prove it could be done with no hope of commercialization.
I think you're only hope is to find used wireless PS2 keyboards somewhere, go wired, create something yourself, or figure out a way to add USB capabilities to the computers.