🚀 go-pugleaf

There are some nifty tone chips available:

Teltone M-991 color burst crystal based, makes all precise tones, 4 bit
control register (makes one tone at a time)
Teltone M-993 color burst crystal based, makes MF tones, same pinout
Mitel MT8880 touch tone tranceiver, microprocessor interface (4 bits
control {read/write}, R/not write line, clock, best suited for motorola
interface though AP notes show intel as well. Also has call progress
mode, will show activity within a passband where precise tones normally
live.
Teltone also has an SIT decoder, special information tones are often
heard on disconnected or cannot complete your call recordings. The
durations of the tones and combinations of different durations mean
different things. Customer owned pay phones often look for these to
determine whether to charge or not for a call (my voice mail box has
SITs on it to save money).

With the teltone 991 available, I cant understand why EVERYTHING
doesn't have precise tones, they're neat!

Normally at apple!zygot!mojave!joe (just visiting up here)