Re: Need Passport Soundchaser interface card schematics (or close-up photos)

["Michael J. Mahon" <mjmahon@aol.com>]

Ralph wrote:
> I'm looking for information on the keyboard interface for the Passport
> SoundChaser keyboard.
> This 49-key keyboard is in a wooden case, and photos
>
> I have the Mountain Computer Music System Cards, light pen, and now
> the SoundChaser keyboard
> (I'm a sucker for computer gear in oak or walnut boxes).  All I need
> is the Apple 2 interface card,
> which has only 5 chips onboard.
>
> If anyone has a close-up photo or other schematics, I'd appreciate
> it!  Even a pinout of the 16-pin DIP
> connector on the keyboard would be helpful, there aren't too many ways
> to do keyboard encoding.
>
> Alternatively, if you know someone within 100 miles of Indianapolis,
> IN or Columbus, OH that has the interface card, please let me know.

That keyboard has velocity sensing, so each key actually breaks one
contact, then makes another.  The interface must sense both events
on all keys changing state.

It's mostly done in software, but it's pretty tricky.

I don't have the circuit, but the software makes its function pretty
clear.

-michael

NadaNet and AppleCrate II: parallel computing for Apple II computers!
Home page: http://home.comcast.net/~mjmahon

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