[Coco] Speech & Sound Pak - carrier frequency of stock voice?

[Robert Gault]

Phil wrote:

> Hi, all --
> 
> What determines the frequency of the carrier wave in the stock voice of 
> the Speech & Sound Pak?  It sounds like it's about 220 Hz, or at least 
> (from what I remember) it's tuned to the pitch A-natural.  Can it be 
> changed with a well-placed POKE?  It'd be fun to make the Coco "sing", a 
> la "Bicycle Built For Two".
> 
> By "stock voice", by the way, I mean the voice you get when typing in 
> the program that's at the front of the Speech & Sound pak manual -- a 
> program that I must've typed in by hand at least 20 times over the 
> years!  I had no Multi-Pak interface, though I suppose I could've saved 
> it to cassette...
> 
> Thanks --
> Phil
> 

There is nothing in the manual that suggests the voice pitch can be 
changed. There are three tone generators in the device but values sent 
to these don't have any effect on voice.

That suggests the voice is hard wired within the LCs and probably is 
linked to the crystal. Change the crystal frequency and the voice pitch 
will probably change assuming the device still worked.