home *** CD-ROM | disk | FTP | other *** search
- Newsgroups: sci.electronics
- Path: sparky!uunet!gumby!wupost!csus.edu!netcom.com!kehoe
- From: kehoe@netcom.com (Thomas David Kehoe)
- Subject: Re: Tone frequencies on telephone
- Message-ID: <1992Nov19.174629.2336@netcom.com>
- Organization: Netcom - Online Communication Services (408 241-9760 guest)
- References: <1992Nov17.075719.23612@riacs.edu> <1eg588INNs78@uniwa.uwa.edu.au>
- Date: Thu, 19 Nov 1992 17:46:29 GMT
- Lines: 14
-
- >or the USA equivalent should be easily obtainable. Basically, each
- >digit (as well as the * and # functions) are composed of 2 frequencies
- >sounded together. All keys in the same Column share the same lower tone
- >(with the lower tone ascending across columns) ... and similarly for the
- >rows.
-
- Which means that there are 16 tones available on a keypad,
- although telephones have only 12 keys. You could easily
- build a keypad with 0-9, #, *, and A-D. What you'd do
- with the A-D keys I don't know...
- --
- "Why my thoughts are my own, when they are in, but when they are out
- they are another's." - Susannah Martin, hanged for witchcraft, 1692.
- Thomas David Kehoe kehoe@netcom.com (408) 354-5926
-