Because the cursor is near the right edge of the screen, something unusual will happen when you type the next character. Press them key. An “O” appears on the screen at the cursor location, but the cursor doesn’t move to the right. Instead, all the text on the screen slides to the left. So the screen will look like this:
Type the letter “R” and it happens again! This hardly seems fair: each time you add a character on the right, you lose a character on the left. Or do you? In fact, the characters that have “disappeared” are still in the virtual screen, but you can’t see them because they’ve scrolled to the left of the LCD window.
You can bring those characters back into view with the cursor keys. Move the cursor far enough to the left, and the LCD window will move to the left, too, because the LCD window scrolls auto- matically, to keep the cursor in view. Thus, as the cursor moves to the left through the virtual screen, the LCD window will follow it, so that once again you will see the “missing” characters.
Virtual screen width
Using the cursor keys, place the cursor just to the right of the last character you’ve typed. Now continue typing your expression, Eventually the screen will look like this:
The next letter in the expression is “O”, and when you press the q key you might expect to see your text scroll horizontally yet again. But what happens? After an “O” appears at the cursor loca- tion, the text doesn’t scroll to the left. Instead, the cursor moves one space to the right. So the screen will look like this:
f-ALL GOOD MEN TO CO- I
Your text didn’t scroll to the left, because the LCD screen was
42