Re-installing a TouchTone keypad in an ASR-33

Tony Duell ard at
Sun May 17 12:41:53 CDT 2009

> On 16 May 2009 at 20:17, Ethan Dicks wrote:
> > ... and the schematic...
> > 
> >
> One of my favorite schematics!  Generating DTMF with a single 
> transistor.  ISTR that the 113 modem was equally sparse in active 

Yes, it's pretty clever...

> devices, but I can't find a schematic anywhere.

THis is mildly OT, but does anyone know of a source of the schematic for 
the computer-interfaced autodialler (is that a model 108???) with an 
RS336 interface from about that time? Finding the actual unit would be 
even better, but I suspect that's impossible over here.


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