It used to be so easy to get away with things in school. The teacher, after all, was always turned around writing at the chalkboard! But then came a bit of technology, previously mostly used for military purposes, called the overhead projector. It would change far more than just the disciplinary record of students everywhere.

In this episode of Version History, we tell the story of the overhead projector. David Pierce is joined by The Verge’s Jake Kastrenakes and Stanford professor Antero Garcia to discuss how overhead projectors were developed, how they made their way into classrooms, and how they changed so much about the way kids learn. They also try to figure out why overhead projectors have mostly gone away, and whether the things that replaced them — from PowerPoint presentations to computer screens to those new-fangled smart boards — actually improved on the OHP.

This is the final episode of the fifth season of Version History, all about the most iconic school tech. Thanks so much for watching, listening, sending feedback, and everything else! Other than the OHP, we also spent this season looking at Oregon Trail, the original Chromebook, the One Laptop Per Child program, the LeapFrog LeapPad, and those ubiquitous Texas Instruments calculators. If you missed any part of our season, check out the episodes here:

If you want to know more about the overhead projector, here are some links to get you started: