SINCLAIR ZX Spectrum User Manual

by Steven Vickers
and Robin Bradbeer

PDF Edition 2004
prepared by Colin Woodcock,

ZXF Magazine (www.zxf.cjb.net)

© 1982 Amstrad
Amstrad has kindly given its permission for

the redistribution of its copyrighted material,
but retains that copyright.

Front cover illustration by John Harris of Young Artists

Contents

CHAPTER 1 The computer and setting it up. Page 5

CHAPTER 2 The keyboard. Page 8

CHAPTER 3 Numbers, letters and the computer as a calculator. Page 11

CHAPTER 4 Some simple commands. Page 14

CHAPTER 5 Simple programming. Page 17

CHAPTER 6 Using the cassette recorder. Page 21

CHAPTER 7 Colours. Page 25

CHAPTER 8 Sound. Page 27

CHAPTER 9 Inside the case. Page 29

1. The Computer and setting it up

This short booklet has been written for two types of people. First, those who know
nothing, or next to nothing, about computers, and, secondly, for those who are
familiar with computer based systems but who like to read instruction booklets
before plugging anything in.
There is a second, thicker book which is the BASIC programming manual. This
should not be read by the novice computer user until this booklet has been read
and understood.

Unpacking the ZX Spectrum, you will have found:

1 This introductory booklet and the BASIC programming manual,

2 The computer. This has three jack sockets (marked 9V DC IN, EAR and MIC),
one TV socket, and an edge connector on the back where you can plug in extra
equipment. It has no switches - to turn it on you just connect it to the power supply.

3 A power supply. This converts mains electricity into the form that the ZX
Spectrum uses. If you want to use your own power supply, it should give 9 volts DC
at 1.4 A unregulated.

4 An aerial lead about 2 metres long, which connects the computer to a television.

5 A pair of leads about 75 cms long with 3.5 mm jack plugs at each end. These
connect the computer to a cassette recorder.

You will also need a television - the ZX Spectrum can work without one, but you
won't be able to see what it is doing! It must be a UHF television (in the UK); if it is
not built to receive BBC2 then it is no good. As its name implies, the ZX Spectrum
gives a colour signal which if you have a colour television, will produce a colour
picture. If you only have a black and white television, then the colour will appear as
black, white and six different shades of grey; but apart from that, a black and white
television will work just as well as a colour television.
The components of the system should now be interconnected thus:

5

Chapter 1

TV

TV

mains

lead

Mains
electricity

Power
supply
unit

Mains lead

TV EAR MIC 9V DC in

UHF
Aerial
Socket

Figure 1

If your television has two aerial sockets marked UHF and VHF, then use the UHF
one (UK).
Turn the power on and switch on the television. You now need to tune the
television in The ZX Spectrum operates on channel 35 UHF (UK) and when it is first
plugged in and properly tuned it gives a picture like this:

Figure 2

When using the computer, you will probably want to turn the volume on the

television right down.

If your television has a continuously variable tuning control, then you just have to

6

Chapter 1

adjust it until you get the picture shown in figure 2. Many televisions now have an
individual push button for each Station. Choose an unused one and tune it in.

For use in countries that have a different TV system to that in the UK a version
of the ZX Spectrum specially designed for that system is necessary. The UK uses
a UHF system with 625 lines and 50 frames per second. It also uses a colour
encoding system called PAL. Most countries in Western Europe (except France)
use a similar system, and the computer should operate in these countries without
any modification. The USA, Canada, and Japan, for example, use a totally different
TV system and a different version of the computer is required.

When you turn the ZX Spectrum off, all the information stored in it is lost, One
way of keeping it for later is by recording it on a cassette tape. You can also buy
tapes that other people have prepared and so run their programs. The lead with
two jack plugs at each end is used to connect a standard cassette recorder to the
ZX Spectrum. Chapter 8 of this booklet explains this further.

Now that you have set up the computer, you will want to use it. The rest of this
booklet tells you how to do that; but in your impatience you will probably already
have started pressing the keys on the keyboard, and discovered that this removes
the copyright message. This is good; you cannot harm the computer in this way.
Be bold. Experiment. If you get stuck, remember that you can always reset the
computer to the original picture with the copyright message by taking out the '9V
DC IN' plug and putting it back again. This should be the last resort because you
lose all the information in the computer.

WARNING.

Do not try to use the ZX 16K RAM with the ZX Spectrum. It will not

work.

7

2. The Keyboard

The keyboard of the Spectrum is very similar to a standard typewriter. The letter
and number keys are in the same place; however each key can perform more than
one function. On a normal typewriter the letters appear in lower case, and when
used in conjunction with the shift key, appear as upper case (capitals). The
Spectrum keyboard is just the same.

To help you know what mode the keyboard is in, a reversed out (white on black)
letter appears on the screen indicating the position of the next character that
appears when a key is pressed. The letter is flashing to distinguish it from any
character already on the screen. It is called the cursor.

When first switched on the Spectrum shows a copyright message on the screen.
Pressing any key brings up the word printed below the letter on the key, (this is
called the keyword). This is because the computer is expecting a command from
you to tell it what to do and all commands must begin with a keyword. Unlike most
other computers the Spectrum allows you to enter keywords with only one key
depression.

For example, if the P key is pressed immediately after turning on, the keyword
PRINT appears on the screen. The “ symbol is marked on the P key as well. To
get it, you must press two keys at once; hold down the SYMBOL SHIFT key, which
is near the bottom right-hand corner of the keyboard, and while still doing that,
press the P key.

Figure 3

The cursor now changes to an L, as a Letter is now expected by the computer.
Type in the letters "Hello". If there is already some other text, for example, on the
screen turn the computer of (remove the 9V plug) and start again. Use the CAPS
SHIFT key to get the upper case H. In general, anything coloured white above the
key requires CAPS SHIFT to access, and anything coloured red on the key
requires SYMBOLS SHIFT

A command beginning with PRINT tells the computer to write the letters enclosed

8

Chapter 2

in the double quotation marks onto the screen. For this command to be executed
by the computer, the ENTER key must be used. When this has been done the
screen should display the word

Hello

and some other characters. (A flashing question mark indicates a mistake
somewhere. If this happens start again and repeat the exercise). The message at
the bottom is really the computer reporting back that everything has gone 'OK'. The
message is important when running programs but can be ignored at the moment.

Notice something else: The letter O and the numeral 0 are represented by
different characters. It is important to remember this, The numeral 0 always has a
line through it. The computer will always interpret the letter O as a letter, so don't
press the wrong key. Similarly, the numeral 1 and the lower case letter L are
different and unlike some typewriters, these cannot be interchanged.

As the keyboard mode is so important to understand it is useful to summarise
what happens once again.

The flashing character L is called the cursor. It shows whereabouts on the screen
the computer will put the next thing that you type. It is not always an L; if you turn
the computer oft and on and then press ENTER the copyright message will change
into a K cursor. The letter that it uses tells you how the computer will interpret the
next thing that you type. At the beginning of a Line it will be a flashing K standing
for 'keyword'. (The copyright message and reports also count as a flashing K) A
keyword is one of the computer's special words, occurring at the beginning of a
command to give the computer a general idea of what the command is going to tell
it to do. Since the computer is expecting a keyword at the beginning of a line, when
you press - say - the P key the computer decides not to interpret this as a P but as
PRINT; and it warns you that it is going to do this by making the cursor a K. When
it has the first keyword, it doesn't expect another one so what you type now will be
interpreted as letters. To show this, the computer changes the cursor to an L - for
'letter'.

These different states are often called modes - we shall talk about keyword (or K)
mode, and letter (or L) mode.

If you want to type a lot of capital letters without holding CAPS SHIFT down, you
can make all letters come out as capitals by first pressing CAPS LOCK (CAPS
SHIFT with 2). To show this is happening, the L cursor will be replaced by a
flashing C (for ‘capitals'). To get lower case letters and the L cursor back, press
CAPS LOCK a second time.

(If you press CAPS LOCK during keyword mode, you will not immediately notice
any difference, but you will see the effect after entering the keyword when the
computer will be in C mode instead of L mode).

As well as keywords, letters, numbers and various programming and scientific
expressions, the keyboard also has eight graphics characters. These appear on the
number keys 1 to 8, and can be printed onto the screen in a similar way to letters
and numbers. To do this the keyboard must be changed to graphics mode. This is

9