Question: How does a computer work?

Michael Nolan answered on 14 Nov 2013:

Hey Hugh

the computer needs to be broken down into its simplest possible concept. That is a device that takes some input (such as numbers or text) and does something to that input (a mathematical operation, a change, writing it to storage).
The piece of the computer that is required for this is the central processing unit (CPU, usually Intel or AMD) that acts on all the information received. It is made up of many billions of transistor switches that when put to ON/OFF in the correct way will manipulate information in the form of 1’s and 0s (as switches have only two states: ON (=1) or OFF (=0).

The other bits such as memory or disk allow you to store the information before it is fed into the CPU for processing and then stored in this new form.

Everything you do is broken down into a series of machine level instructions that fetch, manipulate, move and store a series of 1’s and 0’s in the CPUs memory registers. I learned this years ago and it is rather tedious, so layers are put between you and the CPU: these include the keyboard and operating system (windows, linux). The OS takes your high level inputs (text, numbers, etc) and converts them into the series of 1’s and 0’s for the CPU along with the step by step instructions for the CPU to work on these data.

some resources:
http://homepage.cs.uri.edu/faculty/wolfe/book/Readings/Reading04.htm
http://www.howstuffworks.com/pc.htm
http://en.wikipedia.org/wiki/Turing_machine