Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!mit-eddie!mit-amt!rdsnyder
From: rdsnyder@mit-amt (Ross D. Snyder)
Newsgroups: sci.electronics
Subject: Re: How to Hack Payphones (?!)
Keywords: hack, payphone
Message-ID: <3838@mit-amt>
Date: 10 Jun 89 17:42:27 GMT
References: <3685@tank.uchicago.edu> <2803@portia.Stanford.EDU> <3218@kitty.UUCP>
Distribution: usa
Organization: MIT Media Lab, Cambridge, MA
Lines: 46

In article <3218@kitty.UUCP>, larry@kitty.UUCP (Larry Lippman) writes:
> In article <2803@portia.Stanford.EDU>, mesmo@portia.Stanford.EDU (Chris Johnson) writes:
> > 	Another interesting phone mini-hack: back in high school,
> > 	our pay phone could be dialed for free by rapidly clicking
> > 	the hang-up toggle in the pulse-pattern of the number you
> > 	wished to dial.
> 
> 	While the above method of operation is also true for 1A-type and
> 1C-type single-slot coin telephones arranged for pre-pay operation, I
> do not believe it is possible to "pulse-dial" the switchhook on these
> style coin telephones due to its different mechanical design (obviously
> intentional!).
> 
That's right.  The 1C-type, and probably the 1A-type, paystations have a
mercury switch in the switchhook mechanism, so when you try to "switchhook
dial," the mercury splashes all over the inside of the mercury switch.

Also, since the single-slot DTF paystations are connected to ACTS (stands for
some combination of automatic/automated coin toll/telephone service/system;
telco personnel are so reliant on acronyms that even they usually don't know
exactly what the acronyms stand for and will make something up if you ask.),
even if you connect a lineman's butt-in test set across tip & ring and dial,
you will only hear ACTS begging for money.

> > 	any ideas why pulse-dialing isn't disabled from touch tone
> > 	payphones (at least that one) ?
> 
> 	While it is possible to block rotary dialing in some ESS central
> office apparatus, there really is no need to do so with dial tone first (DTF)
> coin telephone service since the telephone user IS ALWAYS permitted to dial
> the initial call.

Also, telcos like to keep pulse dialing enabled on all of there lines since
most IRT's (installation and repair technicians) and especially cablemen,
who are at risk of dropping their butt-in test set into a few feet of muddy
water at the bottom of a manhole, prefer a more robust buttinski, such as the
classic Western Electric 1013B which has no DTMF capability, to the cheesier
all-electronic buttinskis that have appeared in the last few years.
 
> <>  Larry Lippman @ Recognition Research Corp. - Uniquex Corp. - Viatran Corp

By the way, Larry, could I get a copy of your BSP's on the WECO 24V4 rptr that
you mentioned a few months ago to someone interested in building a phone patch.
I have several 24V4C's and need to know the batt & gnd connections.  I tried
sending e-mail, but got no reply.  Thanks.
-Ross