To make the computer do something, you
have to type in an instruction it
understands. This instruction can be a
direct command which it carnes out

The instructions in a program have to be
very carefully worked ou:. The computer
will attempt to carry out your instructions
precisely, even if they are wrong.

1O1H1OLNOOI
VOOOL1O1OMOLO
LLOOIOLIHOLOM

|

| Al] the work inside the computer is done
with a code of tiny pulses of electricity.
Your instructions are translated into

'.. computer code by a special program
inside the computer called the

interpreter.

ui o gong onone——ee ee oe oo oe vz-z»7-—Ž—o —Yr

i WANT THE
COMPUTER TO
DO THIS

LATER ON

J0 PRINT "TMREE ROBOTS
ARE FANTASTIC'"
4% END :

straight away, or it can be a programof
instructions which it stores in its memory
and does not carry out until you give itthe
go-ahead.

v,
4 vs
»y: A A

4

The computer cannot understand
instructions written in our language, so
you have to write them in one of the many
computer languages. Some ofthese
languages are described opposite.

Each piece of information in computer
code is represented by patterns of pulses.
Computer code can be written down
using | to represent a pulse and 0 to show
there is no pulse.

Computer languages

You could write programs in computer code but it would be very difficult. Instead, there
are special computer languages, called high level languages, which the computer can

translate into its own code.

There are hundreds of different high level languages, many of them specially
designed to do one particular kind of work. BASIC is one of the most common
languages. The letters stand for Beginner's All-purpose Symbolic Instructon Code. Itis
not just used by beginners though. Below there are examples of three different

languages.

This is a short program in This program is written in This is a language called
BASIC. Line 10 tellsthe Pascal, a language named PILOT. It is used to write
computer to print "Whatis aftera famous French programs to help people
your name" onthescreen. mathematician. Itis partofa learn new subjects. In tus
Then the computer stores program to work out details language, the computer can
your answer in its memory recognize answers even if
and if your name is Brian or they are not exactly right.
George, it prints outa

message to you.

At first glance, computer languages seem
very strange and difficult, but then, so do
other languages such as the Finnish
shown on the right, until you get to know
them. There are lots of other subjects too,
in which special languages are used. For

"Minus fifteen I guess.

"TMTAA OLLA VUISITOISTA
ASTETTA PAKKASTA"

formulae which would need alot of
ordinary words to explain them and other
kinds of notation are used to write down
chess moves or music.