Background: I currently have two computers connected to my keyboard, mouse, and display via a KVM switch -- the KVM switch uses PS/2 connections for the mouse and keyboard.
One of the connected computers (running Jessie) uses a PS/2 to USB cable adapter to a USB port to interface to the KVM switch. The other computer (running Wheezy) uses the PS/2 cables from the KVM to connect to the computer. I soon want to set up a 3rd computer to install stretch, and, eventually, take the Wheezy computer out of service, but, in the meantime, I want to have 3 computers connected to my keyboard, mouse, and display and will need to buy a 4 way KVM switch. The less expensive KVM switches nowadays use USB connections for the mouse and keyboard (and then to the computers). The Question: Will it be straightforward to convert the Wheezy machine (which has USB ports) to use a USB port instead of the PS/2 ports to connect the mouse and keyboard (via the KVM switch) -- is it as simple as shutting the computer down, changing the cables, and rebooting, or is it more involved. If it is more complicated, what would I have to do?