What exactly happened after Roper obtained the calculator? Did he divide by zero?

I was really upset that he couldn't be kept as a souvenir. Quite sure the calculator wouldn't be using solar power any longer. Maniacal laughter powering simple arithmetic would probably bring back the balance anyway.

If you play dreamfall you'll find out. ;)

The weirdest part of the whole game. If there's something to indicate what's going on, I must have missed it.

I always thought he went into it of his own volition, but then couldn't get back out. I won't give it away, but as previously stated his ultimate fate is revealed in Dreamfall.