ACTION! CORNER
by Kevin Greggain
by Kevin Greggain
Computer languages come and go with time because of many factors. One of these is speed. How fast a program will run is very important to someone who is writing a fast-action game. If it was written in BASIC, the game would be too slow. To take the big step and write the game in assembly language would take a long time with a lot of hard work. This is where ACTION! comes along. Although it is a high-level language, like BASIC, when compiled RUNS quickly like a low-level language.
The thing that makes this language so unique is how easy a BASIC programmer could switch over to using it. A complete BASIC program could be converted over to ACTION! and may run over 10 times as fast. In this article, I'm first giving you a program that will run a number of spectacular graphic demos. These demos, if written in BASIC, would be so slow they'd be boring, but in ACTION!, they are fast and colorful. Each demo has comments to make them easier to understand.
The second program is just a short one that moves the character set from ROM to RAM for use in your own custom character set. In the next issue a complete listing to a game written in ACTION! will be given.
MODULE ;WE'RE GOING TO D
ECLARE SOME
BYTE C4=704, ;GLOBAL VARIABLES
FOR USE BY THE
C5=705, ;PROCEDURE CALLS
C6=706, ;C4-C12 ARE THE R
EGISTERS FOR MODE 10
C7=707,
C8=708,
C9=709,
C10=710,
C11=711,
C12=712,
LM,RM,
BM,RO,
LOOP,C=E17, ;C IS THE POINTER
VARIABLE USED FOR THE COLOR
ATT=77, ;ATTRACT MODE AT
77 IS ALWAYS RESET TO 0
LOOP1,LOOP2,
CONSOLE=53279 ;THE CONSOLE KEYS
PROC COL() ;THIS ROUTINE SET
S THE SEOUENTIAL BUT RANDOM COLORS TO
DRAW WITH
BYTE NUM
NUM=RAND(14)*14
C4=0 C5=NUM CG=NUM+2 C7=NUM+4 ;SETS C
OLORS TO COLOR BASE TO COLOR BASE+14
C8=NUM+6 C9=NUM+8 C10=NUM+10 ;SAME A
5 BASIC POKE
C11=NUM+12 C12=NUM+14
RETURN
PROC SCROLL() ;THIS I
S THE ROUTINE TO PUT IT ALL TOGETHER O
NCE IT'S DRAWN
BYTE WSYNC=54282, ;WAIT S
YNC LOCATION
VCOUNT=54283, ;VERTIC
AL LINE COUNTER
CLOCK=20, ;RTC CL
OCK AT 18,19,20 USED FOR TIMING
CLOCK2=19, ;
CLOCK3=540, ;JIFFY
COUNTER
C01=$D012, ;SCREEN
REGISTER FOR GRAPHICS 10
TEMP ;TEMPOR
ARY STORAGE VARIABLE FOR LOCAL USE
CLOCK2=0 CLOCK3=240 ;SET CL
OCK TIMERS
DO ;BEGIN
LOOP
IF CLOCKS=0 THEN ;COMPAR
E 540 WITH 0 (CLOCK COUNTS BACKWARDS F
ROM 240 AS ORIGINALLY SET)
TEMP=C12 ;STORE
REGISTER INTO TEMP..SIMILAR TO PHA IN
ASSEMBLY]
C12=C11 ;THESE
FOLLOWING MOVES SWAP THE COLOR REGISTE
RS
C11=C10
C10=C9
C9=C8
C8=C7
C7=C6
C6=C5
C5=TEMP
CLOCKS=2 ;RESET
540 TO 2 (2 60ths OF A SECOND)
FI
IF VCOUNT<=61 THEN ;CHECK
54283 FOR <=61 (APP MID SCREEN)
WSYNC=1 ;STORE
AT NSYNC
C01=VCOUNT+CLOCK ;STORE
COLOR IN REGISTER $D012
;IS CON
DITION TRUE
;NO SO
GO TO SECOND PART
ELSEIF VCOUNT>=62 THEN ;BIGGER
THAN MID SCREEN?
WSYNC=1 ;STORE
AGAIN
C01=VCOUNT-CLOCK ;STORE
COLOR -CLOCK FOR REVERSE SCROLLING EFF
ECT
FI ;END OF
CHECK
UNTIL CLOCK2=10 OR CONSOLE=6 ;LOOK F
OR CLOCK 19=10 OR START KEY PRESSED (C
ONSOLE=6 =START)
OD ;END OF
SCROLL ROUTINE
ATT=0 ;TURN O
FF ATTRACT IF ON
RETURN ;ATTRAC
T ENABLES AFTER LOCATION 77>=128
PROC DR() ;THE DR
# PROCEDURES ARE USED BY THE MAIN ROUT
INE TO DRAW THE IMAGES.
LM=0 RM=79 BM=191 RO=0 ;WE SET
THE LEFT RIGHT BOTTOM AND TOP MARGINS
FOR USE WITHIN THE PROGRAM
GRAPHICS(10) C4=0 ;SET UP
MODE FOR SCREEN AND SET SCREEN COLOR
TO 0 (BLACK)
COL () ;CALLS
BACK TO THE COL() PROCEDURE WHICH SETS
THE COLOR REGISTERS
DO
COLOR=C
PLOT (LM,RO)
DRAWTO(RM,RO)
DRAWTO(RM,BM)
DRAWTO(LM,BM)
DRAWTO(LM,RO)
C==+1 IF C>6 THEN C=1 ;THIS C
HECKS FOR C AND RESETS IF COLOR > 8 TO
1
FI
LM==+1 PM==-1 BM==-1 RO==+1
UNTIL LM=79 OD
RETURN
PROC DR2()
LM=0 RM=79 BM=191 RO=0
GRAPHICS(10) COL C1
DO
FOR LOOP=LM TO RM DO
COLOR=C
PLOTCLOOP,RO) C==+1
IF C>9 THEN C=1 FI
OD
FOR LOOP=RO TO BM DO
COLOR=C
PLOT(RM,LOOP) C==-1
IF C<1 THEN C=9 FI
OD
LOOP=RM
DO
COLOR=C
PLOT(LOOP,BM) C=C+1
IF C>9 THEN C=1 FI
LOOP==-1
UNTIL LOOP=LM
OD
LOOP=BM
DO
COLOR=C
PLOTCLM,LOOP7 C=C-1
IF C<1 THEN C=9 FM
LOOP==-1
UNTIL LOOP=RO
OD
LM==+1 RM==-1 BM==-1 RO==+1
UNTIL LM=40 OD
LM=39 RO=95 BM=95 RM=39
DO
COLOR=C
PLOT (LM, RO) DRAWTO(RM,RO)
DRAWTO(RM,BM) DRAWTO(LM,BM)
DRAWTO(LM,RO)
C==-1 ZF C<1 THEN C=8 FI
LM==-1 RM4==+1 RO==-1 BM==+1
UNTIL LM=10 OD
RETURN
PROC DR3()
BYTE X,Y
GRAPHICS(10)
COL ()
FOR LOOP=0 TO 100 DO
COLOR=RAND(9)+1
X=RAND(79)
Y=RAND(100)
PLOT(X,Y)
OD
LM=0 RM=79 BM=191 RO=10
DO
COLOR=C
PLOT(LM,RO) DRAWTO(LM,BM)
DRAWTO(RM,BM) DRAWTO(RM,RO)
C==-1 IF C<1 THEN C=8 FI
LM==+1 RM==-1 BM==-1 R0==+3
UNTIL LM=37 OD
RETURN
PROC DR4()
GRAPHICS(10) COL()
FOR LOOP1=30 TO 50 STEP 2
DO
COLOR=C
C==+1 IF C>8 THEN C=1 FI
FOR LOOP2=LOOP1 TO LOOP1+2
DO
PLOT(5,LOOP2) DRAWTO(74,LOO
P2)
OD
OD
FOR LOOP1=150 TO 189
DO
COLOR=C
C==+1 IF C>8 THEN C=1 FI
PLOT(0,LOOP1) DRAWTO(79,LOOP1)
OD
FOR LOOP1= 5 TO 70 STEP 9
DO
C=1
FOR LOOP2 =LOOP1 TO LOOP1+6
DO
COLOR=C
C==+1 ZF C>8 THEN C=1 FI
PLOT(LOOP2,149) DRAWTO(LOOP2,5
3)
OD
OD
LOOP1=39 LOOP2=39 RO=0
DO
COLOR=C
PLOT(LOOP1,R0) DRAWTO(LOOP2,R0)
R0==+1 LOOP1==-1 LOOP2==+1
C==+1 IF C>8 THEN C=1 FI
UNTIL RO=30
OD
C=0
FOR LOOP1 = 35 TO 45
DO
COLOR=C
PLOT(20,LOOP1) DRAWTO(59,LOOP1)
OD
RETURN
PROC DR5()
GRAPHICS(10) COL()
LM=0 RM=79 BM=95 RO=0
DO
COLOR=C
PLOT(LM,R0) DRAWTO(RM,R0)
DRAWTO(RM,BM) DRAWTO(LM,BM)
DRAWTO(LM,RO)
PLOT(LM,95+RO) DRAWTO(RM,95+RO)
DRAWTO(RM,95+BM) DRAWTO(LM,95+8
M)
DRAWTO(UM, 95+RO)
C==+1 IF C>8 THEN C=1 FI
LM==+1 RM==-1 BM==-1 RO==+1
UNTIL LM=69
OD
RETURN
PROC INTRO() ;I WILL ADD SOME
INSTRUCTIONS HERE
GRAPHICS(10) ;GRAPHICS 24+16 (W
ITHOUT TEXT WINDOW)
POSITION(1,0)
PRINTDE(6,"use
to quick")
;PR INTDE(6,"TEXT") IS THE METHOD
POSITION(1,2) ;TH
AT ACTION USES FOR THE EQUIVALENT OF B
ASIC'S
PRINTDE(6,"advance pictures or ") ;PR
INT#6;;"TEXT"
POSITZON(1,4)
PRINTDE(6,"Wait and they Will")
POSITION(0,6)
PRINTDE(6,"change after a short")
POSITION(2,8)
PRINTDE(6,"period of time")
POSITION(0,10)
PRINTDE(6,"press
to go on")DO ;BE
GIN LOOP
UNTIL CONSOLE =6 OD ;AN
D WAIT TILL START IS PRESSED
RETURN
PROC MAIN() ;THIS ZS THE MAIN RO
UTINE WHICH CALLS BACK TO THE DRAW ROU
TINES.
;NOTICE HOW NICE YOU
CAN FORMAT THE TEXT TO SUIT YOUR READ
ING NEEDS
INTRO ()
DO
DR1() SCROLL() ;THIS CALLS THE DR1
ROUTINE WHICH CALLS COL() THEN SCROLL(
)ETC.
DR2() SCROLL() ;AND 2
DR3() SCROLL() ;
DR4() SCROLL() ;
DR5() SCROLL() ;AND DOWN TO 5
OD ;CONTINUE FOREVER
RETURN
;YOU CAN ADD YOUR OWN DRAWING ROUTINES
TO THE SYSTEM BY
;JUST LABELING THEM DR# WHERE NUMBER I
S THE ROUTINE TO USE
;REMEMBER TO ADD THE ROUTINE CALL INTO
THE MAIN() ROUTINE AND CALL THE SCROL
L() ROUTINE TO GET
;THE RAINBOWING EFFECT AFTER YOU ARE F
INZSHED..
;THE TIMER VALUES IN SCROLL() CAN BE I
NCREASED TO SUIT YOUR VIEWING TIMES.
PROC CSET()
BYTE CHBASE=756, ;POINTE
R FOR CHARACTER BASE
RAMTOP=106, ;TOP OF
FREE RAM (USUALLY 40960)
WSYNC=54282, ;WAIT S
YNC
VCOUNT=54283, ;VERTIC
AL LINE COUNTER
CO1=$D01A, ;HARDWA
RE REGISTER FOR SCREEN (GR.18)
CO2=$D016. ;HARDWA
RE REGISTER FOR 708
CLOCK=20 ;RTC AT
18,19,20
CARD ROMSET, ;VARIAB
LE FOR STANDARD SET
LOOP ;FOR LO
ADING IN CHARACTER SET
BYTE ARRAY NEWSET ;VARIAB
LE FOR NEW SET
RAMTOP==-4 GRAPHICS(18) ;4 PAGE
S-1024 BYTES
;GRAPHI
CS 0 RE INITS POINTER
NEWSET=RAMTOP*256 ;SET UP
NEW START FOR CHARACTER DATA
ROMSET=CHBASE*256 ;ESTABL
ISH OLD ROM CHARACTER SET
MOVEBLOCK(NEWSET,ROMSET,1024) ;ZAPP..
COPY OLD ROM DATA TO NEW LOCATION
CHBASE=NEWSET/256 ;POINT
TO MY NEW SET
CLOSE(1) OPEN(1,"D1:FANCY",4,0);OPEN C
USTOM CHARACTER SET DATA FILE
FOR LOOP=0 TO 1024
DO
NEWSET(LOOP)=GETD(1) ;GET AN
D STORE BYTE IN NEW CHARACTER SET LOCA
TION
OD
CLOSE (1)