This reminds me of some arcade games that had a "Suicide battery" onboard as a form of DRM. A security key was embedded in these arcade board's processors whic

This reminds me of some arcade games that had a "Suicide battery" onboard as a form of DRM. A security key was embedded in these arcade board's processors which could correctly decode the rom. The key was backed by a battery. If the battery ran out, the key was lost forever so it was much harder for pirates to copy the rom. See also: https://en.wikipedia.org/wiki/CP_System_II https://en.wikipedia.org/wiki/CP_System_II https://hackaday.com/2016/09/15/desuiciding-capcom-arcade-boards/ https://hackaday.com/2016/09/15/desuiciding-capcom-arcade-bo...