How are computers made?

We started by showing the stuff that computers are made of. It all begins with common sand,
which consists mostly of silicon dioxide (quartz). Using chemical methods, the sand is converted
to pure silicon. Very pure silicon, 99.999 999% -- you can’t get anything more pure.
Pure silicon is a funny material. It shines like a metal, but is breakable like a ceramic. It is a
semiconductor. That means it is on the edge: does it conduct electricity or doesn’t it? Well, we
can make it do both: make it conduct, or make it stop conducting.We can switch an electrical
current in silicon on or off, at will, and very, very fast. From silicon, we make fast switches!
A whole bunch of those switches together make a chip, which is put inside a plastic cover.
A bunch of chips are mounted on a printed circuit board.
A bunch of boards make an electronic box: a VCR, a TV, a radio, a computer.
Well, of course you need more stuff, like a power supply, a display, a hard drive, and a box to fit
it all in. But the heart of anything electronic is those silicon switches.