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HOW COMPUTERS WORK
(The Most Important Discovery by Humans)
Steve Krar
A computer, a digital information-processing machine, works by changing information
into binary numbers (ones and zeros) and then using simple mathematics to make decisions
about how to rearrange those numbers into words or actions. A digital system stores and operates
on information in a very specific way by storing information in a bit (or multiple collections of
bits). A bit is a variable that can have only one of two values: it can either be a 1, or be a 0.
There are two main things to understanding the basics of how a computer works:
• A computer treats any type of information (not only numbers but also letters, words,
dates) as if it consisted simply of binary ones and zeros. For example, a computer can
translate the letter “A” typed into its keyboard into a string of ones and zeros, such as
1000001. One reason for this is that once it is in a binary form, the information can be
stored and moved about more easily. On a hard disc, the “ones” could be stored as
magnetized spots on the disc, while the zeroes can be stored as un-magnetized spots.
Once information has been converted to ones and zeros, the computer can get to work.
• The second point to consider is that the computer’s functions are based on the movement
and transformation of electrical pulses (representing ones and zeroes) in electrical
circuits. Inside the computer are electrical circuits that decode the zeros and ones, by
adding and subtracting them. These circuits are called the logic of the computer, because
the calculations they make are similar to simple logic decisions. For example, if you press
the A key on the computer keyboard, circuits inside the computer receive pulses of
electricity representing the A in binary form - 1000001. Those pulses are sent to logic
circuits that make yes or no decisions based on the input they receive. A very simple
example would be a circuit that determines whether the input send to it is a one or a zero.
The output of the circuit is a new piece of information - a binary one or zero that is the
result of the simple yes or no decision.
Main Computer Parts
The Three Subsystems of a Computer
