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Giving the computer information

To make the computer do something more useful than just displaying
things on the screen you have to give it information or "data' to workon
The computer stores this information in its memory until you tellit to useit

Another way

l0 READ A You a aa na

—— correct oflabel
20 READ B for numbers and
40 DATA6,231, FRIDAY

Commas

These are the
numbers to
bestoredin
the computer's
memory.

Some computers need
their data words in
guotes.

Another way to store information is with When you run the program the
These are the the words READ and DATA, as shown computer puts each piece of data ina
labels for the above. The READ lines tell the computer memory space, taking them in order. The
emory spaces. to label memory spaces and the DATA items of data must have commas in
line contains the information. between so the computer knows how long
When you puta piece of data intothe can use the word LET, as shown above. A | Some programs each one is."
computer s memory you have to giveita labelled memory space is calleda

label so you can find it again. You canuse vanable because it can hold different data
letters of the alphabet as labels. To labela at different umes in the program.
memory space and put a number in it you

Ouotes

—

10 LET A$<"ROBOTS ARE GREAT"
20 LET B$-"IF YOU LIKE"

30 LET C$<"GREAT METAL IDIOTS"'
40 PRINT A$

50 PRINT B$

60 PRINT C$
k 70 END
RUN -
Here are two programs, one using READ ROBOTS ARE GREAT
Don'tforget and DATA and the other using LET to IF YOU LIKE
guotation marks. store information in the computer s GREAT METAL IDIOTS

You use a different kind of label to store You put a string in a memory space s

letters and symbols in memory spaces. using LET in the same way as for anumber More about variables You cannot use these
Letters and symbols are called "strings" variable, but the letters and symbols must words as variable label
and you use letters of the alphabet with be enclosed in guotation marks, as shown asthey contain

dollar signs to label them, e.g. C$." above. BASIC words.

— IMOILM— nn

inova are labelled o inthe called a string variable. The contents of

| | | Computer s memory where informationis variables can change during the

times g am.
k Mm dra mom ... mai aa Soil: saga ega i stored. A variable containing numbersis Somecomputers can use words sa ikilale
| zma ne nes k kdo leg z dotgčaa information. The data in called a number variable and one (or variables, but not words which contain

which contains letters and symbols is BASIC words as this would confuse the
computer.

program prints out the information from the variables stays the same until you
' variables B, D$ and L$. change it.

"You cannot use this method on the ZXB1 computer.
"This is pronounced "C dollar" or "C string".

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