Figure 3-6 Effect Of Interlaced Mode On Edges Of Objects - Commodore Amiga Hardware Reference Manual

Non-I nterlaced Interlaced
Figure 3-6: Effect of Interlaced Mode on Edges of Objects
When you use the special blitter DMA channel to draw lines or polygons onto an inter-
laced playfield, the play field is treated as one display, rather than as odd and even fields.
Therefore, you still get the smoother edges provided by interlacing.
To set interlaced or non-interlaced mode, you write
to
bit 2, LACE,
III
register
BPLCONO:
Interlaced mode - write 1 to bit 2.
Non-interlaced mode - write 0 to bit 2.
As explained above in "Setting the Number of Bit-Planes," bits in BPLCONO are not
independently settable.
The following example shows how to specify high-resolution and interlaced modes.
BPLCONO EQU $DFFlOO
MOVE.W #$A204,BPLCONO
;BPLCONO address
; Write to it
The example above also sets the following parameters that are also controlled through
register BPLCONO:
o High-resolution mode is enabled.
o Two bit-planes are used.
40 Playfield Hardware