Looking for a Game I Played That May Not Have Been a Game

Hive-mind, I have a question. I’m trying to find a piece of software (hopefully it’s been updated a few generations) that I used in the mid- to late-1980s. There’s a 25% chance that it was for the Apple II plus, a 35% chance that it was for Windows 3.1, and maybe a 40% chance that it was DOS. It had a German name, I’m 90% certain it began with a “Z.” It may have even been “Zettelkasten.”

I didn’t use it for “Smart-Noting,” I thought it was a game, a murder-mystery-solving game. It had virtual 3 x 5 cards. You could write one item on it, maybe 100 characters? You could tag each card with a 15-character tag and mark it with colors indicating

  • who
  • what
  • where
  • why
  • when
  • or how

 

Then the fun began. You had two kinds of windows to then look at the data. If you used it sort-of like a spreadsheet, you could sort it in various ways. That was kind of useful, but I tended to prefer the window where you “dropped the cards all over the floor and drag them when you thought you saw relationships.” Either way, when you looked at the information, you would often see a new bit of information based on what you could see. And then you would create a new card.

Does anyone else remember seeing this software? How difficult would it be to create?