1. You may hit [ENTER] and retype the whole line. The incorrect line will be erased from memory
and then be overwritten by the next line to be typed that starts with the same line number.
2. You can press the [<-] key and move the cursor block back to the incorrect entry:
10 FOR N = 332 TO 255
Note that the character underneath the cursor is displayed in reverse video. In other words, the
character which is normally the colour of the cursor has become the same colour as the background
(the ‘paper’) so it will show through the cursor block that is presently placed over the top of it.
Now press the key marked [CLR] (short for CLEAR) and the character within the cursor will
disappear - and the line closes up to fill the gap:
10 FOR N = 32 TO 255
Press [ENTER] again, and this corrected line will be the one that the computer remembers. The
cursor doesn’t have to be at the end of the line - the computer enters the whole line - irrespective of
the cursor position.
3. You can also take the cursor back to the character immediately to the right of the one that you
wish to delete:
10 FOR N = 332 TO 255
Now press [DEL] (short for DELETE), the character to the left of the cursor is deleted, and the
cursor pulls the line along behind it without affecting the character within the cursor.
Press [ENTER] and the line will be stored as before.
10 FOR N = 32 TO 255
1.2.8 Afterthoughts
The preceding methods are fine if you spot the error before you reach the line end and type
[ENTER]. Most errors, however, occur inadvertently and only come to light when you try to run the
program - and the computer responds with an error message (APPENDIX VIII).
A number of errors will cause the computer to display the faulty line, with the editing cursor placed
over the first column (left end). If this is the case, then you can use the procedures above as if you
had spotted the error before entering the program line.
If the error does not prompt you with the faulty line, you will have to LIST the program, find the
cause of the problem, and fix it.
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