What's the Meaning of Call Center?

When did the word call center actually happen? Have you also read igoe sens of that? I saw, like mid eighties for some places. But it's not, it doesn't look like it any time before the eighties even though there was a couple of decades before that. My first real contact center, we had 200 employees, but we only, and we had a hundred of a hundred desks, or a hundred desk tops. So across a 24 hours span, we had about 200 employes.