1 1 2 1 6 3- 1 1 2 1 9 6
1 1 # 9 6 3 2- # # 9 6 9 6
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The DTMF generator above has the ABCD key sequence from the Silver Box – phone phreak phavorite.
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| 1209 Hz | 1336 Hz | 1477 Hz | |
| 697 Hz | 1 | 2 | 3 |
| 770 Hz | 4 | 5 | 6 |
| 852 Hz | 7 | 8 | 9 |
| 941 Hz | * | 0 | # |
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DTMF signalling is celebrating its 50th anniversary this week – let’s celebrate with a little music.
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