The keyboard of the Spectrum is very s imilar 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 ar once; hold down the SYMBOL SHIFT
key, whis is near the bottom right-hand corner of the keyboard, and while still
doing that, press the P key.
The cursor now
changes to an  ,
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
off (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 in the double
quoter on 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. Similarily, 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 happtens once
again.
The flashing
character
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 ;
if you turn the computer off and on and then press ENTER, the copyright
message will change into a 
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
standing for 'keyword'. (The copyright message and reports also count as a flashing
).
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 go ing to do this by making the cursor a .
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
- 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 snow this is happening, the
cursor will be replaced by a flashing 
(for 'capitals'). To get lower case letters and the
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 done by pressing the CAPS SHIFT key with the 9. Notice the cursor change
to a  .
Pressing the 9 key will change back to L mode.
There is one
last mode that the keyboard can be changed to. The extended mode, indicated
by an 
cursor, is obtained by pressing CAPS SHIFT and SYMBOL SHIFT at
the same time. This allows most of the scientific and programming functions
to be used. Pressing the two SHIFT keys again will revert the keyboard
back to letter, L, mode.
Even if you
are the most proficient typist, or programmer, wrong keys get pressed. So far
the only way to overcome this has been to pull the plug out! Although this may
be convenient if only one command has been given to the computer, it is certainly
very inconvenient if a lot of information has already been entered.
Luckily we can
use the DELETE key to change errors. For example, not much can go wrong
with the simple command:
PRINT "Hello"
... or can it?
Let's assume
that you didn't use the SYMBOL SHIFT key to get the opening quotes. The
screen would show
PRINT PHello"
The computer would not have recognised what came after PRINT
as no quotes indicates to the ZX Spectrum that a number is expected - and it found
a letter instead. It shows its confusion by flashing a 
at the end of the line.
Fortunately
you don't have to type it all out again. On the top row of the keyboard are
four arrows pointing in different directions and the word DELETE. To
operate these keys, you have to use the CAPS SHIFT key when you press
them. The sideways arrows move the cursor to the left or the right, and the
DELETE key rubs out the character immediately before the cursor.
To correct your
nonsense line, press  (CAPS
SHIFT and 5 at the same time) until the cursor is just after the
P that you put in by mistake - if you hold them down for a second or
two, then they wil start working continuously, emitting a quiet clicking sound.
In fact if you keep your finger on any key for more than about three seconds
it automatically repeats itself. Key in DELETE (CAPS SHIFT and
0) to delete the wrong P, and then type " (SYMBOL SHIFT
and P) to insert what should have been there - note that it is inserted
without overwriting anything else. Try the cursor right key as well, just to
get the hang of it. If you made any genuine typing mistakes, correct them in
the same way, remembering that you can't overwrite mistakes; you have to delete
them and then insert the corrections.
Now, when you
press ENTER, the computer will write your message at the top of the screen
- or underneath the one it did the first time, if that is still there.
A full description
of the keyboard can be found in Chapter 1 of the BASIC programming manual.
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