The first I found in Subzin is from [*WarGames* (1983)][1]. Here's the first mention:

> 00:19:52 - You're really into computers, huh? - Yeah.

> 00:19:59 - What are you doing? - I'm dialing into the school's computer.

> 00:20:14 They change the **password** every couple of weeks, but I know where they write it.

> 00:20:32 - Are those your grades?! - Yeah.

> 00:20:35 I don't think that I deserved an F, do you?

Here's a screenshot:

[![the password is pencil][2]][2]

Others:

> 00:25:35 They might have changed the **password**.

> 00:32:15 I put in a **password** that only I know about.

> 00:35:32 so I could get his secret **password**.

> 00:36:18 If I could just get that damn **password**, I could play the computer.

> 00:52:28 The kid broke into the war game using a **password** left by the original programmer.

> 00:52:33 - A **password**? - Yes, sir.

> 00:52:43 We can find the **password** and take it out, but it might help to beef up security.

> 01:36:08 It's like the entire **password** file has been wiped out.

> 01:38:15 They've taken out my **password**.


  [1]: http://www.subzin.com/quotes/M9143247f/WarGames/They+change+the+password+every+couple+of+weeks%2C+but+I+know+where+they+write+it.
  [2]: https://i.sstatic.net/HvriR.jpg