Atari XL

10 The A tar; XL Handbook
the SHIFT keys, so any of the other keys may have
three different uses.
Try moving the cursor around the screen (it will
continue to move for as long as you press the key).
Notice that when the cursor reaches one edge of the
screen it reappears at the opposite edge.
The TAB key is used in the same way as that on a
typewriter. Pressing TAB moves the cursor right
to the next preset posi tion. You can set and clear
the tab stops by using SHIFT and TAB together to
add a new stop at the current horizontal position of
the cursor, and CONTROL and TAB together to
clear a stop. When you first switch on the Atari
there are five TAB stops set automatically, at eight
column intervals across the screen.
You will notice after a little experimenting that the
TAB key may move the cursor to different positions
on successive horizontal lines. This is because, as
you will discover later, it is possible to type an
instruction which extends over two or even three
lines of the screen, and the TAB key is moving to
preset points along this 114 character line.
Screen Scrolling
When you move the cursor down to the bottom of
the screen with the cursor keys, it will reappear at
the top and continue to move downwards.
However, if you use the RETURN key to move
downwards, when the cursor reaches the bottom
the display will begin to move upwards. This
movement is called scrolling. Anything which
disappears from the top of the screen can not be
recovered, as the screen will only scroll one way.