[CodeWriter23]

Never used an auto-dialer myself, but it would be trivial to code one. Just send ATDT<number> out the serial port and see if "CONNECT" comes back before timing out.

Back in that time, I think a good rate was $0.01/minute for a local call on a consumer landline. Unlimited calling plans came later. Not attributing any intent to the telco, just saying, there would be no cost issue to motivate an investigation.

[SJC_Hacker]

It definitely wasn't local - he was in Washington but dialed into Sunnyvale, CA.

I can't remember charges for local exchanges (same area code), but I only remember as far back as the late 80s. It was something like 10 cents a minute. I remember all the adds about "friends and family" special rates/etc. Metering on voice calls persisted into the 2000s.

But the calls were very brief (if they did pick up) unless he got a "hit". So thousands of calls could have no charge

Or maybe he spliced into his neighbors line :-)