thats a rotary dial line, basically a row of usually 16 - 32 computers dialing numbers in sequential order, when it makes a hit, it sends a signal back to the people at the terminals who 'answer' your call kinda like having someone call people for you and then hand you the phone.
i was figuring out how to 'shut them down' so I could go home instead of working when I was 15 doing telemarketing.
we called them 'dialers' hahaha but that term is used in the adult world too. different meaning though.
