Did anyone actually think that touch screen tablet computers were a brand new idea? The iPad is essentially just a scaled up iPod Touch anyway.
Still, it is interesting to see how long some ideas stay on the drawing board before they turn into consumer products.
There's an illustration similar to the iPad in the 1983 Orbis Home Computer Course, in an article predicting the home computer of 1990's. Along with making the LCD touch screen the only input method and predicting wireless connectivity, they even got the size, thickness, and borders around the screen pretty close to Apple's design.

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