Re: A89: >1-bit sound on the 89


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Re: A89: >1-bit sound on the 89




On Sat, Apr 15, 2000 at 22:09:22 +0300, Henri Moilanen wrote:
> 
> [...]
> Other way, which could also be used, is to output variable length pulses to
> the link port. Then if the overall pulse frequency is high enough, and if it
> was filtered away, then the variable length pulses would end up being (on
> average) different voltage levels. They could then be pulsed to generate the
> sound. 
> [...]

I did this to produce square wave music with four independent voices on a
TI82. (I even wrote a MIDI file converter!) The sound quality was pretty
good, except that it was optimized for *speed* (i.e. sound quality) instead
of frequency precision... *grin*

The TI89 is another story, the sound is very soft and I haven't found any
way to improve this. Anyway, I guess that at least two-bit-level sound is
possible with reasonable sound quality (modulo it's only two bits).


/Johan



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