I got a main board out of a mini grand - dead as a post - and it’s got a CPU chip on it labelled RWA828 (see picture). The chip has got clock running but nothing else - no address or data traffic between it and any RAM and ROM.
Can’t find anything about it - would like to get my hands on a data sheet
Anyone on his forum know what it is of has details about it? I would like to have a closer look why it is not running and what needs to be done for a reset - but I need data sheet for that 
Looks like you might have to buy 10, but here you go:
I couldn’t find a datasheet, but I bet DSYK would be willing to send you one.
Ouch! No original pics of the chip, and a quite low price. That’s a little bit smelly…
I found a little bit more about it. The board is out of an Artesia Digital Mini Grand - the chip doesn’t seem to be available as a part but the entire module, also called a “RWA828 Main Board” is available and it comes with a programming port (top left on the picture below). I think this is some sort of a generic digital piano sound do everything kind of a board … there’s no names or identifiers on it at all …
