[sdiy] circuit bending a yamaha fm piano question

[Andre Majorel]

On 2002-08-23 08:27 +0100, Peter Blackett wrote:

> just thought I would let you know that I've now looked at the info in
> the voice rom for the Yamaha pf15 piano .
> most of the eprom is blank ! 
> but the data for the 10 preset voices is there in blocks of 64 bytes .

Looking at the dump, I see data from 800h to A7Fh (640 bytes)
and from C00h to E7Fh (640 bytes). That's 128 bytes per voice.

At <URL:http://www.teaser.fr/~amajorel/misc/pf15.png>, you'll
find a graphical representation of the data (byte values mapped
to grey levels), with 64 bytes per line. If you look closely,
you'll see that while there is indeed a periodicity of 64, there
also seems to be a (weaker) 128-byte periodicity.

The packed format voice dump for 6-operator is 128 bytes long.
I'll look into it...

-- 
André Majorel <amajorel at teaser.fr>
http://www.teaser.fr/~amajorel/