Another thought relating to this article.
If there were another dramatically energetic event like the one on the 1850's, then the chances could be fairly high that all computers might also be fried like a burnt piece of toast.
Would a serge protector be sufficient to stop the frying?
If there was mostly copper wiring, then switching off the computer would save the circuitry. If it had sufficient iron in the computer you'd have no change.
Q. How much iron is actually in the computer circuitry? 