Bleg

When I was in high school I remember finding in a book a way to make a crude syllogism computer using just index cards, a hole punch, scissors and pins (or sticks). There were holes punched in the cards, some of which were closed (i.e., circles) and others of which were open (i.e., the holes were like a little U-shaped bite into the card). There was a master card with a key to all the holes, and you'd stack the cards together, put pins in the holes that represented the propositions, and shake the stack a bit. Some of the cards would fall out and -- if I remember correctly -- those cards had the syllogisms that were valid with those propositions. I made it and thought it was the greatest thing for a while. I have no clue where I found this, but I've wanted since to find the instructions for it. Has anyone come across this themselves, or knows in what book it is found?