This comes when modems were prevalent in the tech support industry. When a customer bought our system they would get a modem for us to dial in and do support. One time a customer called complaining the system did not work. I asked her to turn on the modem so I can get connected. She said ok and I tried dialing in. I get no connection. I ask her again to make sure the modem was turned on and plugged in. I told her its the black box on top of her PC. She says “The modem is on now.” Still no luck. I ask if the computer is on, she says “Ya thats the modem, its on.” I said “no the black box of the PC.” She said, “This little black box on top of the modem.”