[sdiy] Where to get special white keys?

[John Mahoney]

>>I'm slowly thinking of building my own keyboard. It would not have the
>>usual octave pattern/layout, and instead have alternating white and
>>black keys.
>
>Hey, that's an idea I had decades ago! It seemed quite appealing to
>me: learn two major scales, one starting on a black, one on a white
>key and you can play them all. ...

I don't think so. Assuming that each key is one semitone higher than 
the previous key, a major scale would go like this:
         white, white, white, black, black, black, black (and then 
back to white at the octave)

Or, am I missing something?

John