Figure 3-24 Horizontal Scrolling - Commodore Amiga Hardware Reference Manual

the left-hand side of the window as bits on the right-hand side disappear off-screen. For
each pixel of delay, the on-screen data shifts one pixel to the right each display field.
The greater the delay, the greater the speed of scrolling. You can have up to 15 pixels
of delay. In high-resolution mode, scrolling is in increments of 2 pixels. Figure 3-24
shows how the delay and extra data fetch combine to cause the scrolling effect.
0-15 bits of
delay will cause
the system to
show the
early-fetched
word.
Background Color
''''--Data Fetch 21 Words---.I
• ..---Display Window --~
Display position in example
is shown with D-bits of delay.
As delay is added,
on screen display
shifts this
direction.
This data is
displayed if
scroll
=
0
16 Bits
.... --320 Bits (20 words)---I~
(1
word)~=::::!+-+!::~
_ _ _ _ _ _ _ _
+-____ . . . .
o
-
Figure 3-24: Horizontal Scrolling
This data is
displayed if
scroll
=
15
Playfield Hardware 75