Date   : Wed, 19 May 2004 12:07:49 +0100 (BST)
From   : Matt Callow <mattcallow@...>
Subject: Re: Sound wave representation

 --- Charles Ripperton <charlesripperton@...> wrote: > Hi
Beeb fans,
> 
> I've got some queries about BBC Micro sound / playing samples.
> My understanding is that the SN76489 is capable of 4-bit sound
> sample playback, and that the nybbles used are unsigned. In
> other terms, the value 15 means the highest positive wave
> amplitude, the value 0 means the lowest negative wave
> amplitude
> and somewhere between the values 8 and 7 is the
> 'zero displacement'. 
> 
> Is this accurate? If I'm incorrect, then please explain what
> the true situation is. Cheers.
> 
> Charles.

[snip]

I don't  think that the sound ship can produce an output like
and ADC for example.  I was reading an article on Superior
Software's "Speech!" program the other day, which explains how
it was done. 
Take a look at:

http://bbc.nvg.org/doc/Speech.html

Matt


       
       
               
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