Castlevania III Password Algorithm
As a kid, I was dumbfounded that passwords worked on NES games, and Castlevania III was my first introduction to the concept. I still remember staring at the screen not comprehending how putting in this combination of icons would get me my game back. I knew there’s no way they could manually create a password for every game state, but I also had no conception of discrete states, algorithms and hashing, so I literally could not conceive of <i>how</i> this thing in front of me worked.<p>It is personally satisfying to finally get a complete understanding (even though I long ago understood it conceptually).