[Coco] Orchestra 90CC

[L. Curtis Boyle]

On Sun, 28 Jan 2007 23:49:47 -0600, Bob Devries <devries.bob at gmail.com>  
wrote:

> Joel, I suspect that there are some set data rates for sound cards, such  
> as
> 44KHz, 22KHz etc. If the FGPA's FIFO could be set up to take the data as
> fast as possible, and then output it at that rate, it would work in a
> similar way to the PC sound card. However, I have no idea what the data  
> rate
> for the Orchestra-90 is.
>
> I wonder if those people who wrote OS9 drivers for the Orchestra-90 would
> know/divulge this?
     It's up to the programmer. My PLAY command, for example, would read  
the frequency from the header of a WAV file, and set up it's timing loops  
to do that as close as possible (the faster it got, the less accurate...  
but you could do sampling close to the 44.1/48 KHz range that CD's and DAT  
tapes use). The faster the sampling, the better quality the sound, but the  
more memory it would take up. To my own ears, sampling speed has more  
effect on sound quality than the # bits per sample (after a certain point,  
anyways)... I was planning on making a custom 2 or 4 bit sampler that  
could use the higher sampling rates to generate decent quality sound in  
less memory, but never got around to it. The inspiration was comparing the  
TC-9 8 bit to the Coco 6 bit... the difference was not as striking as say  
between 11 to 22 KHz sampling rates. (11 being the original Mac standard).

-- 
L. Curtis Boyle