Re: Sound Card-Phase II

From: jiva_at_humboldt1.com
Date: 2001-05-18 19:02:59


> Before we get too excited about this idea it might
> be good to produce a document that lists all the
> advantages and disadvantages.

yes ... and again, i wasn't proposing the idea as an
replacement to the existing project.

However, at this point we don't really have a good
grasp of what the completed existing project will
look like and cost.

> At a minimum, it would be good to see numbers that
> estimate the overall cost to users of both complete
> systems including electrodes. It's not clear to me
> that the savings are significant.
>
> Also, it would be good to see estimates of
> all the relevant performance metrics for both
> systems. Joerg just estimated 7-bit resolution for the card
> with one particular decoding method. What about dynamic
> range, etc., and how do all these measurements compare
> with the "non-sound card" system?
>

I'm still not following Joerg's explanation all that well.
(my lack of tech skills, not his lack of explanation)

Why he opted to put two VCOs on one channel further
confuses me.

> On the software side, we still don't know whether
> we would have to write separate versions of the
> program for each individual sound card, or whether
> we could take advantage of some kind of
> standard abstraction layer in the operating system.
> This makes a huge difference in how practical it
> will be to maintain the code.

a major issue.

and one option I've tossed out several times is
intially working with a given card with known
characteristics. (if a $20 card resolves a bunch
of variables then ... ??)

The soundcard proposal remains useful
* ONLY IF IT MAKES FOR MAJOR COST SAVINGS. *
(an large unknown)
and we don't want it to detract from completing
the current design.

> If it turns out that we need to write separate code
> for each soundcard, I would view that fact as a
> strong disadvantage, because soundcards become
> obsolete and get withdrawn from the market by
> their manufacturers. When that happens, our system
> will become useless to people with new computers
> unless somebody writes a new soundcard driver.
> And is there any guarantee that such drivers could be
> written for future sound cards?

i'd think that would be part of the modular design.
others could add current cards, new cards could
be added later.

with a 'black box': "this in" > "this out" functionality.

another reason for this sort of design would be
cross platform issues.

------------

> > 1. Whether a 2 channel EEG machine would deliver
> > meaning full performance - systems people to please
> > comment

many current EEG machines are 2 channel.



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