I note that PBX operators had 20 pps dials while the rest of us had 10
> pps. Some kids experimented and found 20 pps worked at home. Now, it
> was easy to modify the dial to go faster -- so why didn't Bell have
> everyone at 20 pps -- faster utilization of equipment? I strongly
> suspect there were valid technical reasons not to.
Note -- I subsequently learned we were served by a #1 Crossbar at the time. I believe the office serving the PBX was a panel, as was most of the city.
I have no idea whether the fast dials on the PBX switchboard required a special mod at the central office. As mentioned, someone tried it at home and it worked fine (around 1971).
[TELECOM Digest Editor's Note: I had a couple of Hayes Modems which
> could be switched between pulse and tone dialing, and you could set
> the 'speed' of the pulsing or the 'speed' of the tone signals. You
> could make both modes go quite fast; with tone dialing so fast that
> it was little more than just a single blip in your ear, and most
> times it would work quite well. Only on occassion the modem would
> give its short little blip or tone burst when dialing *before* the
> line was set up to allow it, and you would have to redial, but
> usually it worked okay. PAT]
Modems were easy to adjust using the AT commands. I adjusted my Touch Tone speed to be a little faster than the default, but too fast would not go through. I never tinkered with changing the pulse rate, but there were AT commands to do that as well. I think in foreign countries the "make/break" ratio of pulses was different and I didn't want to risk screwing up my modem/software with an oddball setting. Now it doesn't matter and I ought to experiment with it.
FWIW, I have a Panasonic telephone with an auto dialer. It was rather slow on pulse mode, whether from memory or entered via keys. I could dial a call faster on a real rotary phone than the Panasonic.
In the 1980s I found that some locations not equipped with Touch Tone would still take it but others would not. Now it is included almost everywhere.
Would anyone remember in what year dual-mode phones (keypad with a little switch to convert to pulse if necessary) came out in wide quantity? I think that was around the time they stopped using real ringer bells. My guess is the late 1980s.