I used to be a TTY repairman. Back in the days of Ma Bell, a TTY machine (28 KSR) was kept in a vault in a System owned building in NYC. Whenever a President was to stay in town, this machine was “routined” and placed at POTUS’s hotel. It would be connected to some government equipment that was covered by tarps. One of the few NYTel TTY repairman who had been given security clearance was on call 24/7 and would be housed at that hotel for the duration of the President’s visit. Those tarps would NEVER be removed in the repairman’s presence.
SS told us unofficially that his is what, at the time, was known as “The Red Phone”.
Y, this is not to dispute what you posted since this was before Reagan. However, red phones were NOT that difficult to get. All one had to do was pay the monthly charge for it. Many wire rooms on Wall St. had them.
So the Red Phones were hot lines direct to, as, the WH or military heads?
We cooks used to joke that we could pick up the phone and speak to the Soviet leader (Gorbachev I guess), like he was just sitting on the other end of the line.