Yellow Brick Road
By Peter Ellison
This section in the magazine will be directed to
poke & peek locations and other Atari memory locations that are
looked up alot. This will make it faster for programming because you
won't have to search for certain memory locations all through your
reference manuals every time you program. Every month different
locations will be given. Some of these locations can be found in the
references pages that come with your computer but they won't be all on
a few pages like the ones that will be in this section each issue.By Peter Ellison
Many times for a game or business program a key must be pressed to continue during program execution and below is the location for each key on the keyboard. If no key is pressed PEEK(764) will be equal to 255
KEY | PEEK(764) | KEY | PEEK(764) |
A |
63 |
W |
46 |
B |
21 |
X |
22 |
C |
18 |
Y |
43 |
D |
58 |
Z |
23 |
E |
42 |
1 |
31 |
F |
56 |
2 |
30 |
G |
61 |
3 |
26 |
H |
57 |
4 |
24 |
I |
13 |
5 |
29 |
J |
1 |
6 |
27 |
K |
5 |
7 |
51 |
L |
0 |
8 |
53 |
M |
37 |
9 |
58 |
N |
35 |
0 |
50 |
O |
8 |
+(LEFT) | 6 |
P |
10 |
*(RIGHT) | 7 |
Q |
47 |
- (UP) | 14 |
R |
40 |
=(DOWN) | 15 |
S |
62 |
||
T |
45 |
RETURN | 12 |
U |
11 |
ESC | 28 |
V |
16 |
Below is short program that when run will draw a cross in the center of the screen using the four cursor control arrows.
5 GRAPHICS 5:COLOR 1:SETCOLOR 2,16,1
6 X=35:Y=20
10 T=PEEK(764):IF T=255 THEN 10:REM TO SEE IF KEY IS PRESSED
14 PLOT X,Y
20 POKE 764,255:REM RESET LOCATION 764 FOR NEXT KEY
30 IF T=6 THEN DRAWTO X-5,Y:? "LEFT"
35 IF T=7 THEN DRAWTO X+5,Y:? "RIGHT"
40 IF T=14 THEN DRAWTO X,Y-5:? "UP"
45 IF T=15 THEN DRAWTO X,Y+5:? "DOWN"
50 GOTO 10