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.