The small white flashing line you can see on your TV screen is called the cursor and it shows where the next character to be typed will appear on the screen.
One thing to bear in mind which the keyboard doesn't make obvious - the keys which produce the letters of the alphabet
As you can see, virtually all the keys have more than one character/word printed on them - some even have three! There are four keys on the keyboard whose purpose is to sort out which one appears on the screen when you press a particular key. These are
SHIFT - there are two of these keys
CTRL
CAPS LK / FUNC - this is one key, which is normally 'FUNC' but is 'CAPS LK' when used with the SHIFT key.
These keys are used in various combinations to give you the character or word you want to appear on the screen, and this is described shortly.
The BREAK key clears the screen and prepares the computer for entering a new program. Any program lines already entered will be deleted (but can be recovered by using the OLD
command - see chapter 25).
Holding down the CTRL key then pressing BREAK key clears the screen and restores the computer to how it was when you first switched it on.
The ESCAPE key is used to interrupt a sequence of events generated by the Electron, such as a program listing or program execution etc.
The DELETE key moves the cursor backwards along a line and deletes whatever character it finds there.
When the light is on, the keyboard is in 'CAPS LOCK', and this means that pressing letter keys will give you capital letters, but all other keys will give you the lower of the two black characters on the top of the key.
When the light is off, the keyboard is no longer in 'CAPS LOCK' - the only difference is that the letter keys will give you small letters when pressed.
With the yellow light on, press the SHIFT key, and hold it down while you press one of the character keys. Even though the keyboard is in 'CAPS LOCK', all letters appear on the screen as small letters.
PRINT
appears on the screen. Try pressing the FUNC key with some of the other keys with light brown writing on them.You probably noticed that the keys marked 'f0' to 'f9' won't do anything when you press them. This is because they are 'user definable' keys which means that you can choose what they will do when they are pressed. How you define them is described in chapter 24.
If you have never come across the computer language called 'BASIC', you may wonder what the point is of being able immediately to display these words on your TV screen. The answer is simple; the Electron computer understands and uses the 'BASIC' language, and these words are the most common 'keywords' (or commands) in this language, so rather than having to keep on typing these out in full, you can simply press the FUNC key and the relevant character key. This saves a lot of time when typing lengthy programs into the computer.
For example the key marked
SHIFT and key selects ^ and produces it on the screen
CTRL and key selects ~ and produces it on the screen
If you now press the COPY key, both the 'line' cursor and the 'block' cursor move across the screen, and every character above the 'line' cursor is copied to where the 'block' cursor is. This is a very useful facility for editing programs: the idea is to copy the line with a mistake in it onto a fresh line, and correct the mistake(s) while you're doing it. Editing programs using this facility is described in chapter 7.
2. CAPS LOCK on (yellow light on)
Capital letters, otherwise as above
3. CAPS LOCK on (yellow light on) SHIFT with key
Small letters and top (left) black characters
4. CAPS LOCK on or off FUNC with key
BASIC keywords, as indicated on the front of the keys, are produced
5. CAPS LOCK on or off CTRL with key
Selects top right hand character from keys with three black characters marked on them.
Note: See Appendix A for a list of VDU control codes which can be generated by pressing CTRL and some of the other keys on the keyboard.