Re-installing a TouchTone keypad in an ASR-33

Tony Duell ard at
Thu May 21 12:28:42 CDT 2009

> >> Given that the switch to IC-based tone generators looks to be around
> >> 1982, before the breakup of Ma Bell, I'd say that there are few phones
> >> in thrift stores here of that vintage any more. =A0Maybe at an estate
> >> sale from someone who hasn't moved in 25 years.
> >
> > Were rotary dial 'phones still being made after the breakup? Of the 4 US
> > phones I found in the junk shop [1], 3 of the were rotary dial types (as
> > I said, including this multi-line model 564 or something)
> I couldn't say for certain, but even into the 1990s, the phone company
> charged $1-$2USD/month for TouchTone service.  Mostly by then, it was

As an aside, some of the earlier pushbutton 'phones in the UK (which were 
rensted from the Post Office) used loop disconnect (pulse) dialing. The 
dialer unit had a PCB with 3 or 4 metal-can (TO99 or similar) ICs on it, 
which I never managed to indentify. They may well have been custom.

> > [1] It called itself an antique shop, but many of the items on sale were
> > well under 100 years old.
> I learned on my first visit that in the UK, a hundred miles is a long

My point is that IIRC an 'antique' has to be over 100 years old. 

> way, but in the US, a hundred years is a long time *(I stayed in the
> "New Buildings" at New College - "new" because they were built by

Sounds like you were at what I call 'The Other Place' :-)

> Queen Victoria and dedicated, like so many things, to Albert's memory.
>  A building that age at home would be nearly as old as the State I'm
> from).  For us, "antique" has a substantially smaller scale than for

Sure... This reminds me of a story when I was at Cambridge. An obnoxious 
American tourist (no, not all Americans, or all American tourists are 
obnoxious, but this one was) asked the porter at one of the older 
colleges 'Is the college pre-war'. The porter replied 'Sir, this college 
is pre-America' :-).

> you.  OTOH, I've driven over 1,000 miles in a weekend (closer to 1,200
> miles), to buy a PDP-8/S, FWIW.

Yes, of me, going 100 miles (each way) to pick up a classic computer is a 
long trip. 

> >> If you have access to lift the faceplate, look for a part number
> >> starting in '35' and a manufacturing date prior to 1982. =A0You don't
> >> want a part number starting with '72'.*
> >
> > You are joking, right? I am not going to be able to dismantle a 'phone
> > before buying it. In fact finding US phones over here is non-trivial.
> I am not joking in the slightest.  I'm not suggesting you try this

Except at radio rallies, I have naver had permission to take something 
apart before buying it. Maybe remove clip-on covers, but using tools is a 
no-no. I can understand why -- the seller doesn't know that I have this 
way of gettign things back togther. Equally I don't know that the case 
ising internally cracked and will fall apart when I take out a screw. 

> If it's an ITT or other non-Western Electric phone, I'd wager it's
> IC-based.  AFAIK, only the W-E phones (i.e., pre-breakup) would have
> the 1-transistor-2-coil keypad.

Right. So, alas, the chances of me finding one over here are pretty 
remote :-(


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