But note that it didn't stop the counterfeiters. It just slowed them down. In the arcade business, having that window of time was enough to get the production run done and not have any interference with knockoffs.

Another lesser-known reason for these chips was to lock in a serial number to help identify distributors that were selling outside of their territories. That was the primary reason for the "security" chip in a lot of the pinball machines I worked on back in the 90s.