Path: utzoo!attcan!uunet!lll-winken!ames!ucsd!rutgers!apple!gilley
From: gilley@goofy.apple.com (Tom Gilley)
Newsgroups: sci.electronics
Subject: Re: DTMF (Touch-Tone) --> RS-232 Conversion
Message-ID: <491@internal.Apple.COM>
Date: 27 Jan 89 07:01:36 GMT
References: <1441@thumper.bellcore.com>
Sender: usenet@Apple.COM
Organization: Apple Computer, Inc. (A.T.G.)
Lines: 14

In article <1441@thumper.bellcore.com> pff@thumper.bellcore.com (Peter 
Ferris) writes:

>  I'm attempting to build a DTMF (Touch-Tone) --> RS-232 converter.


Hints:

The Radio Shack (on sale today) DTMF decoder will give you four parallel 
bits which you can connect to the parallel input side of a simple UART.  
The AY-3-1015D UART for TTL or the IM6402 UART for CMOS are easy to use.


Tom Gilley