The IBM 1130 was IBMs cheapest computing system, which could either be used as a standalone unit, or in a lot of cases as a pretty dumb terminal connected to a system/360.
^^ that device right there could be very handy. Most analogue industrial controls use a 4-20mA control signal. That thing takes a 0-5V signal and outputs a proportional 4-20mA signal. If you ever want to hook something like an arduino to an industrial thing, that would be the quickest way to do so.