Punch Cards
In the 1800s, a special
weaving loom was
invented. It used a
punch card. This was
a card punched with
holes. It told the
machine how to
make patterns in the
cloth. Later, the first
computers used
punch cards.
Slide Rule
The slide rule is a
ruler. It has lines of
numbers called scales.
You move the scales
to do equations.
Read on ...
to learn about how people
invented new kinds of computers.
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