1929
As if it wasn't bad enough that they want me to use a random internet service to add a keyboard to a usb wifi receiver, they have the balls to put this for Firefox users. I clicked out of pure curiosity, as I'm not even remotely interested in involving a corporate internet service in getting my keyboard connected to my computer. This is the message you get now on Logi Options software if you have a Unifying Receiver: 
For the curious: https://logiwebconnect.com
EDIT: some people on the thread have brought up that the error message being displayed for Firefox users is due to the WebUSB API not being implemented by Firefox due to security concerns. This still does not justify having to use a web app to plug peripherals to a PC.
5 pin din or gtfo
RJ-45 for my compaq portable keyboard, nothing else will suffice
My IBM spring keyboard had an rj45 but it was to connect the DIN to the keyboard not the other way around.
besides everyone knows real computers where build into their keyboards, no connector required.
Many digital typewriters were just 6502 or z80s with a keyboard and type wheel slapped on, no connectors needed for those either