Msg: 5989 *Conference*
08-28-95 14:09:43
From: RON WIESEN
To : COMET _
Subj: REPLY TO MSG #5987 (DMTF)
There are only 12 Dual-Tone Multi-Frequency (DTMF) emissions that need be generated. Of these, ten are for the numerals 0 through 9 and are of concern. The theory of sampling, either to detect or to emit, hovers around the "Nyquist limit" which when applied to the Model 100 cassette interface indicates that fair fidelity music is obtainible. I know nothing about the acoustic coupler and how it interfaces to the Model 100, so I can't assess it for the Nyquist limit against DTMF emission. I suspect that the interface would pass the test, given that it supports Bell 102 standard Frequency Shift Keying. If you end up in need of technical reference publications (the frequency pairs for the DTMF set, and so on), drop me a line.