PS/2 is an older port type that was predominately used for input devices like keyboards and mice. Lightning is a newer technology used primarily in Apple products. Firewire is not a likely answer, input devices for firewire is rare/nonexistent. Bluetooth is not likely to be supported on a server, especially an old server.
"PS/2 keyboard" or "PS/2 mouse" redirects here. For the physical keyboards normally supplied with IBM PS/2 computers (among other hardware), see Model M keyboard.
The PS/2 port is a 6-pin mini-DIN connector used for connecting some keyboards and mice to a PC compatible computer system. Its name comes from the IBM Personal System/2 series of personal computers, with which it was introduced in 1987. The PS/2 mouse connector generally replaced the older DE-9 RS-232 "serial mouse" …