There's a great doc on the TSP50C10A: http://www.ti.com/lit/ml/spss011d/spss011d.pdf

But I didn't see any obvious way to electronically dump the ROM contents.

Datamath.org says the chip is also in the Super Speak and Math.

If there's no way to electronically dump the ROM, I can pick up another Battleship and try decapping again. But there's no guarantee that I'll be able to read the bits, or if I can, that we can figure out the bit order.