Hacker News Reader

Comment by gruturo | Hacker News Reader

Pretty sure DTMF came way later than pulse dialing - first keypads were just a change of interface but still pulse dialing.

View on HN

If there was an early time when pushbutton phones used pulse dialing, it must have been brief. All of the pushbutton phones that I ever saw as a kid were DTMF. I'm not sure how a pushbutton pulse phone would have worked without digital electronics. This was at a time when, in the US, the phone company had a monopoly on phones, all phones were rented, and you actually paid more for "touch-tone" service.

Later on, the phone regulations were changed, and you could own a phone. That's when cheap pushbutton phones came out, that had a switch allowing you to choose between pulse and tone dialing, because you still had to pay more for touch-tone service and some regions didn't offer it.

The weird thing was, sometimes you had to use both, for instance at my college, the phone system used pulse dialing, but I had to enter a "calling card" code using tone dialing in order to call my parents and put the call on their bill.

I definitely remember (as a child in the UK) that our touch-tone phone had a pulse option that could be switched on the underside. If you flicked the switch then instead of a tone you would hear click-click-click-click when you pressed a number. This would have been in the early to mid-90s, though we were quite poor so the phone might have been older.

It took quite a long time for the UK phone system to be converted to support tone dialing everywhere so there were still places in the UK where pulse dialing was required. The last Strowger exchange, where the pulses directly stepped the switches, was only taken out of service in 1995.

There were phones out there that had a keypad but only supported pulse dialing too; if I remember correctly, my parents had one when I was a kid.

Yes, that's consistent with the US. Consumers were allowed to own their phones, sometime in the late 70s or early 80s. I got my phone with a pulse/tone switch in 1982.

Canada was like this in the 80ies through early 90ies as well -- if it was a rotary phone, it always pulse dialed. But a bunch of the push button models had the switch so you could do either. Tonal dialing was so much quicker!

Interesting! I always assumed that the keypads were introduced at the same time as touch tones. The era of keypad pulse phones must have been very brief as I'm sure I never saw one. Some early keypad phones lacked the * and # keys. Perhaps these were pulse dialed? Must research...

I have such a phone at home, we still use it every day. And it does have * and # keys, but dials the same as the older phones (the keys differ only in length of sound, not tone).

Reply on news.ycombinator.com