From what was posted this looks like an early copy of Roman Black's BTc Project.
The Updated version of the original article, discussion, circuit, code and Tools can be found here: [Roman Black - orig 2001 - rewritten 14 Feb 2008 - updated 30th July 2009] https://www.romanblack.com/btc_alg.htm
and the latest version of the Encoder: BTc Sound Encoder 3.0 Software
(Now v3.0 - web 30 July 2009 - updated 16 Sept 2009) https://www.romanblack.com/picsound.htm
It could make for a good GCBASIC Library or Project.
Last edit: Chris Roper 2019-10-29
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I remember using zx spectrum mic socket to sample 1 bit sound and play it back through ear phone socket.
This looks interesting for pic/avr with some ram http://www.radanpro.com/Radan2400/mikrokontroleri/How%20to%20make%20sound%20with%20a%20PIC%20chip.htm
From what was posted this looks like an early copy of Roman Black's BTc Project.
The Updated version of the original article, discussion, circuit, code and Tools can be found here:
[Roman Black - orig 2001 - rewritten 14 Feb 2008 - updated 30th July 2009]
https://www.romanblack.com/btc_alg.htm
and the latest version of the Encoder: BTc Sound Encoder 3.0 Software
(Now v3.0 - web 30 July 2009 - updated 16 Sept 2009)
https://www.romanblack.com/picsound.htm
It could make for a good GCBASIC Library or Project.
Last edit: Chris Roper 2019-10-29
I think you are correct Chris. I did come across Roman Black's software.
Last edit: stan cartwright 2019-10-29