There was a hard drive on the market in the past for high-security use that had write-protect and an admin mode. Maybe a PIN or something to get to admin mode.

There was a hard drive on the market in the past for high-security use that had write-protect and an admin mode. Maybe a PIN or something to get to admin mode. Memory getting fuzzy on it. The normal usage would be read-only with you saving your data elsewhere or to a write-able partition that had nothing to do with read-only part for OS and apps. Go into admin mode to change those. Otherwise, your system is fresh every boot. People do it with VM's, too. I think you were aiming for something physical with no extra software. That was closest thing I could think to it.