Path: utzoo!attcan!uunet!lll-winken!lll-lcc!ames!hc!pprg.unm.edu!unmvax!tut.cis.ohio-state.edu!mailrus!cornell!uw-beaver!mit-eddie!bu-cs!scotts
From: scotts@bu-cs.BU.EDU (Scott Statton)
Newsgroups: sci.electronics
Subject: Re: DTMF (Touch-Tone) --> RS-232 Conversion
Summary: One more little note
Message-ID: <27498@bu-cs.BU.EDU>
Date: 26 Jan 89 03:50:07 GMT
References: <1441@thumper.bellcore.com> <7139@pyr.gatech.EDU>
Reply-To: scotts@buit5.bu.edu (Scott Statton)
Followup-To: sci.electronics
Organization: Boston University
Lines: 23


Two points about the SSI 20x series of decoders.

The DTMF detector works VERY nicely -- we put it through our "torture"
test and it passed with flying colors.  What, you may ask, is the
torture test?  Pick the ickiest Inter-Exchange Carrier [we chose one
famous for telegrams, not so famous for phone service].  Call a RASU
on the opposite coast [This was done in Boston, so RASU was in
Mountain View, CA] and call back in to the decoder under test.  Send
DTMF at very high rate [12 digits per second] and count total number
of errors in a 5 mintue test.  As I recall, the chip weighed in at 7
mis-decodes.

Other point:  They also make a very nice MF decoder called the
SSI-207.  Unfortunately, they're about $70 in small quantities.  It
appears not everybody uses MF as much as DTMF.  Great for those
semi-secure application machines.  Try & bust me for Blue-Boxing -- my
computer uses it for remote control applications.  [Or, I'll just use
the test-frame at work]

  scotts@buit.bu.edu ... aka N1GAK ...

 "The full-time phone hacker who spends an unholy amount of time with
his Dan-Ray CTSS-4000"