In the late 80s I was messing with a rotary phone hook switch and dialed 117 accidentally, which was the proctor test set. It was an automated phone testing pla

In the late 80s I was messing with a rotary phone hook switch and dialed 117 accidentally, which was the proctor test set. It was an automated phone testing platform, and it would let you test things like the coin receiver and touchtone tones, among other things. I never had the coin sound maker, but I did have a small transcription digital recorder years later that could trick the proctor test set into thinking a nickel had been inserted. I don't remember all the other tests, hopefully there's a webpage somewhere about it.