[DECtalk] three DECtalk questions

[Carlos Fernandez]

The numbers a, b, c, and d are telephone system digits that were used 
previously but have dropped out of usage somewhat. They were used mostly 
to transmit commands to call-management computers, and were most used by 
telephone operators and government telephone systems. This system 
allowed standard numbers to be typed at the same time as system 
commands, instead of requiring that a specific number handle the commands.

Carlos

On 10/13/2015 16:14, Mohamed via Dectalk wrote:
> Hi, so, I have three DECtalk questions that I'm wondering about. So, I 
> know that with DECtalk, you can dial all all the standard phone 
> numbers, and a, b, c, and d. The DECtalk PC only says about those, 
> "for certain handsets only". So I'm wondering, what could a, b, c, and 
> d have been used for? Also, what was the first version of DECtalk that 
> was ported to software? I know the earliest speak window available is 
> from 4.3, but I'm curious if there were software implementations 
> before then. Last but not least, has anyone found the full, complete 
> DECtalk PC documentation? Because it seems there are only 5 sections 
> from the documentation, and I'm wondering if there are others.
> Thanks.
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