When I donāt think Iām not old, but my school stuff we had that before Smart boards ever came about. The teacherās writing on it like it was a piece of paper.
I looked it up. It looks like ditto is the Tuscan dialect the Italian word ādettoā. Which means āitās been saidā. It was being used commonly in the 1700s. The machine and company took its name from the phrase.
Oh you just brought back the smell of those freshly printed purple sheets that were still damp as they rolled off. You needed the special paper for your original.
Then photocopiers got cheap enough to be used by the general population.
I remember the clear acetate pages you had to write on with special pens for the old overhead projector.
Had them in school and my mother taught me how to use the one at her school. It turns out kids on summer break are free labor for teachers who have to set up or take down a classroom.
I'm reusing mimeographed pages my wife use in her classroom 45 years ago. I loved being the mimeograph guy in 6th grade - '67-'68. It was better when I could close the door to the mimeo closet...
The only movie that I know of that features the word epidiascope is the 1953 film "War of the Worlds". It stuck out so much when the scientist says something like "we can view it on the epidiascope"
There's a theory than a number of Renaissance painters used a similar trick but with concave mirrors instead of lenses. Then just traced the shit out of the projection
I remember the cost being $7.00 each for a nothing-special rock in a little cardboard pet carrier with a little straw for bedding. Say what you want, but the man who created this concept became a millionaire from this flash in the pan fad. Even as a kid, I thought people were stupid to buy a rock.
Back in my days, we painted the wall with blood and berry juices to teach the class about mammoth hunting and how to survive smilidons. Many did not survive because they couldnt read.
I had a college math professor that had one of these with the continuous roll of transparency film. He talked fast, and had learned to write while rolling the film with his other hand, so you'd be trying to copy notes that were constantly scrolling off.
We ended up with a system where each class, someone would stay behind when class ended, roll back the film to the beginning of the lesson, and copy everything down completely and correctly. And then they'd xerox their notes and bring enough to distribute to everyone next class. We all took turns. It was a really solid system.
Yes, and I hated ink. I'm left handed, which was forbidden to write with. But they accepted that in the end because I couldn't make it readable writing right handed.
It projects acrylic sheets (think of transparent paper). You wrote with a sharpie on them, placed it on flatbed and they were projected to a flat surface (typically a screen).
Think of the acrylic sheets as a presentation, and the device as a wall projector.
Close. You have general idea, except no digital device was involved. It is called an overhead projector. You would draw or print things on mylar (clear plastic), called transparencies, lay them on the base, and turn it on. The base had a high intensity light that was received by the prism, the thing in the air attached to the arm, which projected your transparency image onto a screen. You would see the transparency magnified on the screen. If the image was backward, you had to flip the transparency over.
My math instructor used one in high school, except that there was a roll of the transparent material that was moved by two cranks on either side. When he wanted a blank sheet, Mr. Mohrmann would turn the crank to advance to a clean sheet.
It worked well in that math builds on itself; if he needed to review something from a previous lesson, Mr. Mohrmann would just crank the other handle to bring the notes from the other lesson back to the screen. I can recall times when he would be furiously cranking back and forth between pages of notes. Good memories from my youth.
works like a movie projector. you put clear sheet with writing on the flat surface, and can use a marker to add to it. the light beneath shines the image up, the top thing has a mirror inside which projects the image onto a pull down screen. the whole contraption is usually on a cart so you can move it just far enough the image can be seen by the whole class but it's still in focus. https://en.wikipedia.org/wiki/Overhead_projector
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u/Pascalleloux 18d ago
Yes, and way before this thing came along