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My dad, who went to Uni in the '70s to do maths and physics, has a Sinclair scientific that looks very similar except has blue LED digits. I don't know the exa
by b5 9y ago
My dad, who went to Uni in the '70s to do maths and physics, has a Sinclair scientific that looks very similar except has blue LED digits. I don't know the exact model.
- nothotdog 9y agothe bright blue LED had not been invented yet, it was probably vacuum flourescent http://www.vintagecalculators.com/html/calculator_displays.html http://www.vintagecalculators.com/html/calculator_displays.h... https://en.wikipedia.org/wiki/Light-emitting_diode#Blue_LED https://en.wikipedia.org/wiki/Light-emitting_diode#Blue_LED