One late night many decades ago, I chanced upon a technical description of the Touch-Tone system. The book I was reading had an explanation of how each key on a telephone sends a combination of two ...

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Phones have come a long way since the old landline days. Our smartphones are light, fast, and have more computing power than NASA used to put a man on the moon.* Some advances came not by adding ...

• 9.0 PSTN operator Most organizations have, and continue to use, a 9 to access an outside line. When a 9 is dialed, a secondary dial tone (stutter tone) is heard. Some legacy PBX (private branch ...

Does a cellphone have a dial tone? Mobile cellphone never have a dial tone. Before the cellphone came into common usage, a dial tone on a landline told you that the line was available; however, it is ...