Operator`s manual

0639 38
063"1 E901
063C
C99F
063E D0F1
0640 60
0641 A013
0643 8a
0644 D0rD
0646 CA
0647 DOFA
0649 60
064A
Example 3.
0600
0610
0620
0630
0640
0650
;
0660 DELAY
0670
DELAY2
0680
0690
0700
0770
0720
sxc
sBc
r$01
cMP
*$9F
BNE DCLOOP
RTS
LDY
r$13
DEY
BNN DLLAYZ
DEX
BNX DEI,AY
RTS
.END
;
;
ROUTINE
SPLAY
;
PUTS A PRETTY
DISPI,AY
ONTO THE SCRNEN
;
CALI, IROM
BASIC WITH THE FOLLOWING
COMMANDS
;
GR. 19: A-
USR(1536)
;
EXIT PROGRAM
WITH
&3
m
10
20
40
50
60
70
80
90
0100
00cc
0110
00cD
0720
00cE
0130
00cF
0140
00D0
0150
00D1
0160
0058
0770
o2c4
0180
D20A
0190
0600 68
0200
0601 85D0
0210
0603 AA
0220
0230
0240
0250
0260
o270
0240
0290
0300
0310
o32n
0330
0604 ADoAD2
0340
0607 290f
0350
0609
c90A 0360
0608 B0F7
0370
TEMP
xl-oc
YLOC
DIST
PHASE
COI,OR
SAVMSC
coLoRo
RANDOM
=
SPI-AY
PLA
STA
TAX
$0600
$CC
$cD
$CE
$cF
$D0
$Dl
$58
TEMPORARY
LOCATION
HORIZONTAL
POSITION
OF
PIXEL
VERTICAL
POSITION
OF
PIXEL
DIST.
OF PIXEL FROM
SCREEN CENTER
COLOR P}IASE
COLOR CHOICE
POINTER
TO BEG. OF DISPI,AY
MEMORY
$o2c4
LOCATION
OF COLOR REGISTERS
$D2OA
HARDWARE
RANDOM NUMBER
LOCATION
POP A ZERO FROM
STACK
PHASE
STORE IT IN PHASX
SET COUNTXR
;
THIS IS THE
MAIN PROGRAM LOOP
;
FIRST WE RANDOMLY
CHOOSE THE
SCREEN LOC. TO MODIFY
;
SCREEN IS
40 PIXELS HORIZONTALLY
BY 24 PIXEI,S VERTICALLY
;
WITH 4 HORIZONTAI,I,Y
ADJACENT
PIXELS PER BYTE
;
HXNCX THERE
ARE 10 BYTXS
PER HORIZONTAL ROW
;
AND
2l ROWS FOR A TOTAL
OF 240 BYTES
;
TO REPRESENT
THE SCREEN
;
BEGIN
LDA RANDOM
GET A IIANDOM NUMBER
AND
/$OF
MASK
OFF I,OWXR NYBBI,E
CMP
'$OA
MUST BE SMALLER TIIAN
10
BCS BEGIN
IF NOT, TRY AGAIN