My friend [Eric]@EricHertz is too busy to fiddle with his physical AlphaSmart Pro, but he did indulge me to take some pictures that show the chip markings better.  So this is a 'D0' variant of the 6811.

Topside:

Bottomside:

The main board is quite small, and looks like a two-layer board, so I might be able to do some significant work using these photos alone.