EasyManuals Logo

Atari XL User Manual

Atari XL
262 pages
To Next Page IconTo Next Page
To Next Page IconTo Next Page
To Previous Page IconTo Previous Page
To Previous Page IconTo Previous Page
Page #189 background imageLoading...
Page #189 background image
Player-Missile Graphics
177
120
READ
F:
POKE
START*2048 +
1024
+
120
+ X, F
130
NEXT
X
150
POKE
POCOL, 28
160
POKE
POSIZE,
1
170
POKE
PMBASE,
START
*8
180
POKE
SDMCTL, 58
190
POKE
GRACTL, 2
200
FOR
X=20 TO
180
210
POKE
POHPOS, X
220
FOR
T=1 TO
10:
NEXT
T
230
NEXT
X
500
DATA
30,
42,
42,
93,
93,
93,
93,
42,
42,
3D,
8,
8,
8, 8,
8,
8, 8,
8,
8,
8,
8,
107,
42,
42,
28
Three
new
control
registers
are
used
by
this
program:
PMBASE
(54279),
SDMCTL
(559)
and
GRACTL
(53277).
PMBASE
is
a
control
register
in
the
ANTIC
chip,
telling
it
where
in
memory
to
find
the
data
tables
for
the
players
and
missiles.
SDMCTL
controls
the
memory
access
of
the
ANTIC,
and
GRACTL is a
GTIA
register,
again
controlling
memory
access.
The
GRACTL
(graphics
control)
register
is
used
as
follows:
Bit
1 is
set
to 1 to
use
memory
tables
for
player
graphics.
Bi t 0 is
set
to 1 to
use
memory
tables
for
missile
graphics.
The
other
bits
ofGRACTL
have
no
meaning.
SDMCTL
is
more
complicated:

Table of Contents

Questions and Answers:

Question and Answer IconNeed help?

Do you have a question about the Atari XL and is the answer not in the manual?

Atari XL Specifications

General IconGeneral
Release Year1983
CPUMOS Technology 6502C
GraphicsANTIC, GTIA
SoundPOKEY (4 channels)
StorageCassette tape
PortsCartridge
Operating SystemAtari BASIC
CPU Speed1.79 MHz
RAM64 KB

Related product manuals