The San Francisco Chronical's online website, SF Gate, has a section on historical photos from the newspaper's archives.
They have a series of pictures of various telephones taken over the years. They include cord switchboards and examples of new technology when introduced (ie early cellular car phones, Touch Tone, new pay phones and booths, various kinds of video phones, and others.)
Photo collection is at:
(Note--it is called "50 years of telephones in San Francisco, but the time range is actually 20-100 years.)
One of the historical telephone photos in that series at
show a Touch-Tone payphone with what appears to be a 2-line vacuum-fluorescent display. Does anyone on the list know what that is? Is it Caller ID? I've never seen a payphone with that feature.
** Moderator note:
It appears that Bernie is talking about photo #9 in the series, as it is the only Touch-Tone pay phone. The caption indicates it is the first Touch-Tone pay phone installed in S.F., and is dated Feb 11, 1972.
This pre-dates the deployment of Caller-ID by roughly 15 years, and thus, that possibility can be safely ruled out. Leaving the question of "what IS it for?" unanswered.
Nothing particularly unusual -- just the card with the telephone number. Note the grey plastic keycaps on the Touch-Tone keypad. Those didn't last very long on pay phones due to vandalism.
Compare that phone with the one on the previous photo taken five years earlier. A short-lived characteristic of that model is the three coin slots -- a holdover from the earlier model. Single coin slots and dial tone first (the ability to dial emergency and alternate billed calls without coins) were often prerequisites to price increases on pay phones.
The "panel" style of pay phone was merely a conventional 3-slot payphone modified with a flat panel in front of it and slots to take the coins to the chutes.
In the 1960s some locations got modernized phone booths, such as circular all glass arrangements with sliding doors or other experimental approaches. The booths at my 1964 local shopping mall were kind of swirled wraparound kiosk. Payphones also came out in ivory or green color, or even with Touch Tone before it was widespread.
It appears in the 1970s Bell System gave up on fancy booths and switched to austere post or plain wall mounts. They were a pain to use in noisy locations.
I don't think the public or regulators cared about the older 3-slot vs. the newer single-slot pay phone. The newer single slot unit had advantages to the phone company in terms of lower maintenance, some additional vandal resistance, and the ability to send electronic signals for coin drops. Those signals enabled the switchgear to 'listen' for coin drops on 1+ coin calls, eliminating the need for an operator to do it*. (Of course, today, of the few pay phones remaining, many don't even allow 1+ coin toll calls. New York City seems to be an exception where most pay phones do offer 25c/minute national long distance. Some NJ Transit station pay phones have that, too.).
As to dial-tone first, actually on rural pay phones served by smaller step-by-step offices, those phones were always dial-tone first. Those pay phones, known as "post pay" were simply in that they had no "hold bucket" for the coins; the coins dropped directly into the coin box. Those phones were simpler than those with hold buckets since they required additonal hardware and relays.
On such phones, customers lifted the receiver, got a dial tone, and dialed the local number. If the party answered, they then had put in coins in order to unlock the transmitter circuit. (For toll calls, they dialed the operator and placed coins when requested). Such phones required battery reversal which apparently was a characteristic of step-by-step switches; the reversal switched in and out the relay controlling the transmitter switch. (According to the Bell Labs history, that reversal had to dealt with in developing new key systems).
(As an aside, I was recently in a rebuilt train station which included some pay phones as part of the design. One was in use. One pay phone had a text typewriter associated with it for deaf usage.)
One comment about another photograph, the one with the then new Trimline phone. Its big feature was the lighted dial (or keypad) in the handset. (It also had a pleasant ringer). Initially the dial used a tiny lamp which required a transformer and wall plug-in, but later used LEDs powered from the phone line.
Today, with so many businesses requiring the caller to press Touch Tone keys to get through, the handset keypad becomes cumbersome to use. (That applies to cordless handsets and cellphones, too). When using such phones on such calls, I find myself constantly moving the handset between my ear and my hand in order to listen and then enter the proper key. Since most businesses today have deep multi-level menus, this gets tiring. I've replaced my outgoing call Trimlines with more traditional 2500 sets.
*TSP/TSPS console switchboards greatly sped up operator handling of pay phone toll calls. The caller dialed the number himself instead of passing to the operator, and the switchgear determined the initial amount and displayed it for the operator to collect. All she had to do was announce the amount due, listen for the coins to drop, and release the call. Overtime was handled automatically, too. But there was full provision for manual handling of a call if necessary. (This of course sounds very mundane today, but in the early 1960s TSP was advanced technology.)