;
;FILL 'ER UP! II
;
;BY TOM HUDSON
;

;
;ALPHABETIC CONSTANTS
;
CA	=	'A'-$20
CB	=	'B'-$20
CC	=	'C'-$20
CD	=	'D'-$20
CE	=	'E'-$20
CF	=	'F'-$20
CG	=	'G'-$20
CH	=	'H'-$20
CI	=	'I'-$20
CJ	=	'J'-$20
CK	=	'K'-$20
CL	=	'L'-$20
CM	=	'M'-$20
CN	=	'N'-$20
CO	=	'O'-$20
CP	=	'P'-$20
CQ	=	'Q'-$20
CR	=	'R'-$20
CS	=	'S'-$20
CT	=	'T'-$20
CU	=	'U'-$20
CV	=	'V'-$20
CW	=	'W'-$20
CX	=	'X'-$20
CY	=	'Y'-$20
CZ	=	'Z'-$20
CCOL	=	':'-$20
;
;PAGE ZERO ITEMS
;

	ORG	$80

LO	DS	1
HI	DS	1
PLOTX	DS	1
PLOTY	DS	1
LOHLD	DS	1
HIHLD	DS	1
SMTIM	DS	1
MOVTIM	DS	1
TIMER	DS	1
DEADFG	DS	1
HSHORT	DS	1
PX	DS	1
PY	DS	1
XI	DS	1
YI	DS	1
DESTNM	DS	1
SHFLIP	DS	1
DESTLO	DS	1
DESTHI	DS	1
SHTIM1	DS	1
SHTIM2	DS	1
SHTIMI	DS	1
SHORTN	DS	1
DIRSAV	DS	1
HOLDSX	DS	1
VBXHLD	DS	1
CPYST	DS	1
CPYCNT	DS	1
;
;MISCELLANEOUS MEMORY USAGE
;
PMAREA	=	$1000
MISSLS	=	PMAREA+384
PL0	=	PMAREA+512
PL1	=	PMAREA+640
PL2	=	PMAREA+768
PL3	=	PMAREA+896
DISP	=	$3000
;
;SYSTEM EQUATES
;
KEY	=	$2FC
CONSOL	=	$D01F
PMBASE	=	$D407
RANDOM	=	$D20A
SETVBV	=	$E45C
XITVBV	=	$E45F
COLBK	=	$2C8
COLPF0	=	$2C4
COLPF1	=	$2C5
COLPF2	=	$2C6
COLPF3	=	$2C7
AUDC1	=	$D201
AUDC2	=	$D203
AUDC3	=	$D205
AUDC4	=	$D207
AUDF1	=	$D200
AUDF2	=	$D202
AUDF3	=	$D204
AUDF4	=	$D206
AUDCTL	=	$D208
PRIOR	=	$026F
ATTRAC	=	$4D
DMACTL	=	$22F
DLISTL	=	$230
GRACTL	=	$D01D
NMIEN	=	$D40E
COLPM0	=	$2C0
COLPM1	=	$2C1
COLPM2	=	$2C2
COLPM3	=	$2C3
HPOSP0	=	$D000
HPOSP1	=	$D001
HPOSP2	=	$D002
HITCLR	=	$D01E
P0PF	=	$D004
P1PL	=	$D00D
STICK	=	$278
STRIG	=	$284

	ORG $6000	;ASSEMBLE ADDR.
	LOC	$1400	;ACTUAL ADDRESS

;
;RELOCATE PROGRAM (DISK VERSION ONLY)
;

MOVEPG	LDA	#$25	;FOR DISK ONLY,
	STA	HI	;THIS SECTION
	LDA	#$14	;MOVES THE
	STA	DESTHI	;PROGRAM TO
	LDA	#0	;ITS OPERATIONAL
	STA	LO	;MEMORY LOCATION
	STA	DESTLO	;OF $1400.
	LDY	#0
COPYLP	LDA	(LO),Y
	STA	(DESTLO),Y
	INC	LO
	INC	DESTLO
	BNE	INCEND
	INC	HI
	INC	DESTHI
INCEND	LDA	DESTHI
	CMP	#DIR/256
	BNE	COPYLP
	LDA	DESTLO
	CMP	#DIR&255
	BNE	COPYLP
	JMP	FILLUP

;
;MAIN PROGRAM STARTS HERE
;

FILLUP	LDA	#$00	;TURN OFF...
	STA	DMACTL	;DMA
	STA	GRACTL	;GRAPHICS
	STA	COLBK	;BLACK BACKGND
	LDA	#$74	;BLUE
	STA	COLPF0	;COLOR0
	LDA	#$C4	;GREEN
	STA	COLPF1	;COLOR1
	LDA	#$0A	;WHITE
	STA	COLPF2	;COLOR2
	LDA	#$34	;RED
	STA	COLPF3	;COLOR3
	LDA	#TITLDL&255	;SETUP...
	STA	DLISTL	;TITLE...
	LDA	#TITLDL/256	;DISPLAY...
	STA	DLISTL+1	;LIST!
	LDA	#$2E	;TURN ON...
	STA	DMACTL	;DMA
	LDA	#3	;TURN ON...
	STA	GRACTL	;GRAPHICS
	JMP	CKSTRT	;WAIT FOR START

START	JSR	$E465	;INIT SOUNDS
	LDA	#0	;CLEAR OUT
	LDX	#127	;ALL ZERO PAGE
CLPG0	STA	$80,X	;USER MEMORY
	DEX
	BPL	CLPG0
	STA	SHORTF	;STOP SHORTS
	STA	SHORTF+1
	STA	SHORTF+2
	STA	SHORTF+3
	LDA	#$11	;P/M PRIORITY
	STA	PRIOR
	LDA	#1	;DON'T SHOW
	STA	SHOOFF	;PLAYER OR STAR
	STA	FILLON	;WE STILL MUST
	JSR	PMCLR	;CLEAR P/M AREA
	LDA	#64	;AND SET UP THE
	STA	STRHGT	;STAR'S HEIGHT
	LDA	#128	;AND
	STA	STRHOR	;HORIZONTAL POSITION
	LDA	#$D0	;NOW LET'S
	LDX	#4	;ZERO OUT
ZSCLP	STA	SCOLIN+4,X	;THE SCORE
	STA	SCOLIN+15,X	;AREAS!
	DEX
	BPL	ZSCLP
	LDX	#5
ZSCLP2	STA	SCOLN2+12,X
	DEX
	BPL	ZSCLP2
	LDA	#0	;THESE ITEMS
	STA	FILLON	;MUST BE SET
	STA	DEADFG	;TO ZERO ON
	STA	NOCCHG	;STARTUP OR
	STA	HITCLR	;ELSE WE'LL
	STA	DMACTL	;WIND UP WITH
	STA	NMIEN	;NASTY THINGS
	STA	HASDRN	;HAPPENING!
	STA	HSHORT
	STA	AUDCTL
	LDX	#5	;LET'S ZERO
CMSLP	STA	SCORE,X	;OUT THE SCORE
	DEX		;COUNTER...
	BPL	CMSLP
	STA	LEVEL	;AND LEVEL #!
	LDA	#3	;WE START WITH
	STA	LIVES	;3 LIVES
	ORA	#$90	;AND PUT THEM IN
	STA	SCOLN2+19	;THE SCORE LINE
	LDA	#$0A	;NEXT WE SET UP
	STA	COLPF0	;THE COLORS WE
	LDA	#$24	;WANT TO USE.
	STA	COLPF1
	LDA	#$94
	STA	COLPF2
	LDA	#$C4
	STA	COLPF3
	LDA	#0
	STA	COLBK
	LDA	#$76
	STA	COLPM1
	LDA	#$3F
	STA	COLPM2
	STA	COLPM3
	LDA	#$34
	STA	COLPM0
	LDA	#DLIST&255	;WE'D BETTER TELL
	STA	DLISTL	;THE COMPUTER WHERE
	LDA	#DLIST/256	;OUR DISPLAY LIST
	STA	DLISTL+1	;IS LOCATED!
	LDY	#INTRPT&255	;TELL WHERE THE
	LDX	#INTRPT/256	;VERTICAL BLANK
	LDA	#6	;INTERRUPT IS
	JSR	SETVBV	;AND SET IT!
	LDA	#PMAREA/256	;HERE'S OUR P/M
	STA	PMBASE	;GRAPHICS AREA!
	LDA	#$2E	;TURN ON THE
	STA	DMACTL	;DMA CONTROL
	LDA	#$3	;AND
	STA	GRACTL	;GRAPHICS CONTROL!
	LDA	#$40	;ENABLE VBI
	STA	NMIEN
	JMP	CLRDSP
PMCLR	LDA	#0	;CLEAR OUT
	LDX	#127	;THE P/M AREA:
PMICLR	STA	MISSLS,X	;MISSILES,
	STA	PL0,X	;PLAYER 0,
	STA	PL1,X	;PLAYER 1,
	STA	PL2,X	;PLAYER 2,
	STA	PL3,X	;AND PLAYER 3!
	DEX
	BNE	PMICLR	;LOOP UNTIL DONE
RETURN	RTS		;WE'RE DONE!
;
;PLOT ADDRESS CALCULATOR
;
;MULTIPLY PLOTY BY 40, THEN CALCULATE ADDRESS
;OF THE SCREEN MEMORY TO BE ALTERED.
;
PLOTCL	LDA	PLOTY
	ASL	A
	STA	LO
	LDA	#0
	STA	HI	;*2
	ASL	LO
	ROL	HI	;*4
	ASL	LO
	LDA	LO
	STA	LOHLD
	ROL	HI	;*8
	LDA	HI
	STA	HIHLD
	ASL	LO
	ROL	HI	;*16
	ASL	LO
	ROL	HI	;*32
	LDA	LO
	CLC
	ADC	LOHLD
	STA	LO
	LDA	HI
	ADC	HIHLD
	STA	HI	;+*8=*40
	LDA	#DISP&255
	CLC
	ADC	LO
	STA	LO
	LDA	#DISP/256
	ADC	HI
	STA	HI	;+DISPLAY START
	LDA	PLOTX	;MASK X POSITION
	AND	#3
	TAX
	LDA	PLOTX
	LSR	A
	LSR	A
	CLC
	ADC	LO
	STA	LO
	LDA	HI
	ADC	#0	;LO & HI NOW HOLD
	STA	HI	;THE ADDRESS!
	RTS		;EXIT!
;
;CLEAR THE DISPLAY MEMORY
;
CLRDSP	LDX	#0	;THIS ROUTINE WILL
	STX	PLOTX	;CLEAR THE SCREEN RAM.
	LDX	#0	;IT GETS THE ADDRESS
DLOOP2	STX	PLOTY	;OF THE BEGINNING OF
	JSR	PLOTCL	;EACH GR.7 LINE
	LDX	PLOTY	;THEN ZEROES OUT
	LDA	#$00	;EACH OF THE
	LDY	#39	;40 BYTES (0-39)
DLOOP3	STA	(LO),Y	;IN THE LINE.
	DEY
	BPL	DLOOP3
	INX
	CPX	#86
	BNE	DLOOP2
;
;DRAW THE COLOR 1 BORDER
;
	LDA	#3	;THIS ROUTINE
	STA	BORNUM	;DRAWS THE 4 LINES
BORDER	LDX	BORNUM	;THAT MAKE UP THE
	LDA	BXSTRT,X	;WHITE GR.7 BORDER
	STA	PLOTX	;ON THE SCREEN.
	LDA	BYSTRT,X
	STA	PLOTY
	LDA	BXINC,X
	STA	BDINCX
	LDA	BYINC,X
	STA	BDINCY
	LDA	BORCNT,X
	STA	BDCNT
DRAWLN	JSR	PLOTCL
	LDA	COLOR1,X
	LDY	#0
	ORA	(LO),Y
	STA	(LO),Y
	LDA	PLOTX
	CLC
	ADC	BDINCX
	STA	PLOTX
	LDA	PLOTY
	CLC
	ADC	BDINCY
	STA	PLOTY
	DEC	BDCNT
	BNE	DRAWLN
	DEC	BORNUM
	BPL	BORDER
;
;THIS SECTION STARTS OFF EACH LEVEL
;
	LDA	#80	;POSITION THE
	STA	PX	;PLAYER 
	LDA	#84
	STA	PY
	LDA	LEVEL	;INCREMENT THE
	CLC		;LEVEL NUMBER
	ADC	#1
	STA	LOWK
	LDA	#0	;ZERO OUT
	STA	SHORTF
	STA	SHORTF+1
	STA	SHORTF+2
	STA	SHORTF+3
	STA	CURLO	;CURRENT TALLY
	STA	CURHI	;WORK AREA
	STA	HIWK
	LDA	#$FF	;TELL DECIMAL CONVERTER
	STA	SLLOC	;NOT TO PLACE RESULT
	JSR	CNVDEC	;CONVERT LEVEL #
	LDA	DECIMAL+1	;GET DECIMAL LEVEL #
	ORA	#$90	;ADD COLOR
	STA	SCOLN2+3	;PUT IN SCORE LINE
	LDA	DECIMAL	;SAME FOR 2ND
	ORA	#$90	;LEVEL #
	STA	SCOLN2+4	;DIGIT
	LDX	LEVEL	;GET THIS LEVEL'S
	LDA	TGTLO,X	;PARAMETERS
	STA	LOWK
	LDA	TGTHI,X
	STA	HIWK
	LDA	STARSP,X
	STA	STRSPD
	LDA	SHTIME,X
	STA	SHTIMI
	STA	SHTIM2
	LDA	#4
	STA	SLLOC
	JSR	CNVDEC	;SHOW TARGET AMOUNT
;
;CLEAR OUT THE TRACKING TABLE THAT
;REMEMBERS WHERE THE PLAYER MOVED
;
CLRTRK	LDA	#0
	STA	SHOOFF
	TAX
CLRTLP	STA	DIR,X	;CLEAR DIRECTION
	STA	LGTH,X	;AND LENGTH ENTRIES
	DEX
	BNE	CLRTLP
	STA	MOVIX	;CLEAR MOVEMENT INDEX
	STA	DRAWFG	;AND DRAW FLAG
GETSTK	LDA	PAUSE	;GAME PAUSED?
	BNE	GETSTK	;YES, LOOP AND WAIT.
	LDA	#$FD	;DO 'WARBLE' SOUND
	STA	AUDF1	;USING SOUND
	LDA	#$FE	;CHANNELS 1-3
	STA	AUDF2
	LDA	#$FF
	STA	AUDF3
	LDA	#$A3
	STA	AUDC1
	STA	AUDC2
	STA	AUDC3
	LDA	#0	;NO ATTRACT MODE!
	STA	ATTRAC
	LDA	HSHORT	;DID SHORT HIT US?
	BNE	JCRSH	;YES! WE'RE DEAD!
	LDA	DEADFG	;DID STAR HIT US?
	BEQ	ALIVE	;NO!
	LDX	LEVEL	;IT HIT US--
	LDA	KILLFG,X	;UNCONDITIONAL KILL?
	BNE	JCRSH	;YES! WE'RE DEAD!!!
	LDA	PX	;NO, IF WE'RE ON A
	STA	PLOTX	;WHITE LINE (COLOR 1)
	LDA	PY	;THEN WE'RE ALIVE!
	STA	PLOTY
	JSR	PLOTCL
	LDY	#0
	LDA	BITSON,X
	AND	(LO),Y
	CMP	COLOR1,X	;ON COLOR 1?
	BEQ	ALIVE	;YES (WHEW!)
JCRSH	JMP	CRASH	;GO KILL PLAYER.
ALIVE	LDA	MOVTIM	;PLAYER MOVING?
	BEQ	GOTSTK	;YES--GET STICK.
	JMP	MOVSTR	;NO, MOVE STAR.
JGSTK	JMP	GETSTK	;GO GET STICK
GOTSTK	LDA	#4	;SET UP THE
	STA	MOVTIM	;MOVEMENT TIMER
	LDA	STICK	;GET THE STICK
	STA	STKHLD	;AND SAVE IT
	TAX		;THEN LOOK UP
	LDA	XD,X	;X DIRECTION
	CLC
	ADC	XD,X
	STA	XI	;AND
	LDA	YD,X	;Y DIRECTION
	CLC
	ADC	YD,X
	STA	YI
	ORA	XI	;ANY MOVEMENT?
	BEQ	JGSTK	;NO, TRY AGAIN.
	LDA	PX	;INCREMENT
	CLC		;PLAYER X
	ADC	XI	;POSITION AND
	STA	CKX	;HOLD IT...
	CMP	#159	;OFFSCREEN?
	BCS	JGSTK	;YES!
	STA	PLOTX	;NO, SAVE IT
	SEC
	SBC	XD,X
	STA	PXWC
	LDA	PY	;INCREMENT
	CLC		;PLAYER Y
	ADC	YI	;POSITION AND
	STA	CKY	;HOLD IT...
	CMP	#85	;OFFSCREEN?
	BCS	JGSTK	;YES!
	STA	PLOTY	;NO, SAVE IT
	SEC
	SBC	YD,X
	STA	PYWC
	JSR	PLOTCL	;LOCATE NEW PLAYER
	LDY	#0	;POSITION.
	LDA	BITSON,X
	AND	(LO),Y
	STA	CKV	;SAVE THE 'LOCATE'.
	STX	CKVX
	LDA	PXWC	;CHECK THE
	STA	PLOTX	;POSITION NEXT
	LDA	PYWC	;TO THE ONE WE'RE
	STA	PLOTY	;NOW IN...
	JSR	PLOTCL
	LDY	#0
	LDA	BITSON,X
	AND	(LO),Y
	PHA		;AND SAVE IT!
	LDA	STRIG	;TRIGGER PRESSED?
	BNE	NOTDRN	;NO!
	PLA		;OK TO DRAW?
	BNE	JGS	;NO!!
	JMP	DRAWIN	;YES, GO DRAW.
NOTDRN	PLA		;NOT DRAWING--ARE WE
	CMP	COLOR1,X	;ON COLOR 1?
	BNE	JGS	;NO, TRY AGAIN
	LDA	CKV	;ARE WE MOVING
	LDX	CKVX	;ONTO ANOTHER
	CMP	COLOR1,X	;COLOR 1?
	BNE	JGS	;NO! TRY AGAIN.
	LDA	CKX	;ALL'S WELL...
	STA	PX	;UPDATE PX
	LDA	CKY	;AND
	STA	PY	;PY,
JGS	JMP	GETSTK	;GET STICK.
;
;THIS ROUTINE HANDLES THE DRAW FUNCTION.
;
DRAWIN	LDA	DRAWFG	;ALREADY DRAWING?
	BNE	DRAWOK	;YES!
	STA	MOVIX	;NO, THIS IS THE
	LDA	STKHLD	;FIRST TIME--SET UP
	STA	DIR	;INITIAL DRAWING
	LDA	#1	;VARIABLES.
	STA	DRAWFG
	STA	HASDRN
	LDA	PX
	STA	INIX
	STA	MINX
	STA	MAXX
	LDA	PY
	STA	INIY
	STA	MINY
	STA	MAXY
DRAWOK	LDA	CKV	;DID WE
	LDX	CKVX	;RUN INTO ANOTHER
	CMP	COLOR2,X	;COLOR 2?
	BNE	NOCRSH	;NO, WE'RE OK.
	JMP	CRASH	;CRRAAASSSHHH!
NOCRSH	LDX	MOVIX	;UPDATE THE
	LDA	STKHLD	;TRACKING
	CMP	DIR,X	;TABLES WITH
	BEQ	SAMDIR	;DIRECTION
	INC	MOVIX	;INFORMATION.
	INX
	STA	DIR,X
	LDA	#0
	STA	LGTH,X
SAMDIR	INC	LGTH,X
	LDA	#3
	STA	BDCNT
	LDA	PX	;NOW PLOT THE
	STA	PLOTX	;LINE WE'RE
	LDA	PY	;DRAWING...
	STA	PLOTY
CCLOOP	JSR	PLOTCL
	LDY	#0
	LDA	(LO),Y
	AND	BITOFF,X
	ORA	COLOR2,X	;IN COLOR 2.
	STA	(LO),Y
	DEC	BDCNT
	BEQ	CKCOLR
	LDY	MOVIX
	LDX	DIR,Y
	LDA	XD,X
	CLC
	ADC	PLOTX
	STA	PLOTX
	LDA	YD,X
	CLC
	ADC	PLOTY
	STA	PLOTY
	JMP	CCLOOP
CKCOLR	LDA	PLOTX	;UPDATE X POS.
	STA	PX
	CMP	MAXX	;CHECK MINIMUM
	BCC	TMINX	;AND MAXIMUM
	STA	MAXX	;X & Y VALUES
	JMP	CHKYMM	;AND UPDATE IF
TMINX	CMP	MINX	;NECESSARY
	BCS	CHKYMM
	STA	MINX
CHKYMM	LDA	PLOTY
	STA	PY
	CMP	MAXY
	BCC	TMINY
	STA	MAXY
	JMP	ENDMM
TMINY	CMP	MINY
	BCS	ENDMM
	STA	MINY
ENDMM	LDX	CKVX	;DID WE DRAW
	LDA	CKV	;INTO
	CMP	COLOR1,X	;COLOR 1?
	BEQ	ENDLIN	;YES! END OF LINE!
	JMP	GETSTK	;NO, GO GET STICK.
ENDLIN	LDA	#0	;WE AREN'T
	STA	DRAWFG	;DRAWING ANYMORE
	JSR	SEARCH	;SEARCH AND FILL!!
	LDA	CURLO	;GET CURRENT VALUE
	STA	LOWK
	LDA	CURHI
	STA	HIWK
	LDA	#15	;PUT AT 15TH
	STA	SLLOC	;POS. IN SCOLIN
	JSR	CNVDEC	;CONVERT TO DECIMAL
	LDA	#1	;NOW REDRAW THE
	STA	RDRCOL	;PLAYER'S PATH IN
	JSR	REDRAW	;COLOR 1 (WHITE).
	LDX	LEVEL	;CHECK TO SEE
	LDA	CURLO	;IF WE'VE HIT
	SEC		;THE TARGET.
	SBC	TGTLO,X
	STA	LOWK
	LDA	CURHI
	SBC	TGTHI,X
	STA	HIWK	;HIT TARGET?
	BPL	NEWLVL	;YES--NEW LEVEL!
	JMP	CLRTRK	;NO, GO CLEAR TRACK
NEWLVL	LDA	LEVEL	;IF LEVEL < 15
	CMP	#15	;THEN
	BEQ	NOLINC	;INCREMENT
	INC	LEVEL	;LEVEL
;
;INCREASE SCORE HERE
;
NOLINC	ASL	LOWK	;SCORE INC =
	ROL	HIWK	;TGT-CUR * 2
	LDA	#$FF	;DON'T PLACE
	STA	SLLOC	;THE RESULT!
	JSR	CNVDEC	;CONVERT TO DECIMAL
	LDX	#5	;AND ADD TO SCORE
	LDY	#0
SCOLP	LDA	DECIMAL,Y
	CLC
	ADC	SCORE,X
	CMP	#10
	BMI	NOCARY
	SEC
	SBC	#10
	STA	SCORE,X
	INC	SCORE-1,X
	JMP	NXSPOS
NOCARY	STA	SCORE,X
NXSPOS	INY
	DEX
	BPL	SCOLP
	LDX	#5	;NOW PLACE THE
SHSLP	LDA	SCORE,X	;SCORE IN
	ORA	#$D0	;SCORE LINE #2
	STA	SCOLN2+12,X
	DEX
	BPL	SHSLP
	LDA	#1	;STOP VBI FOR
	STA	FILLON	;A MOMENT
	STA	SHOOFF
	JSR	PMCLR	;CLEAR P/M AREA
	LDA	#64	;INITIALIZE
	STA	STRHGT	;THE
	LDA	#128	;STAR
	STA	STRHOR	;POSITION
	LDA	#0	;VBI ON AGAIN
	STA	FILLON
	JMP	CLRDSP	;GO CLEAR DISPLAY!
;
;THIS SECTION HANDLES PLAYER'S DEATH
;
CRASH	LDA	#0	;NO WARBLE SOUND
	STA	AUDC1
	STA	AUDC2
	STA	AUDC3
	LDA	#1	;NO PLAYER COLOR
	STA	NOCCHG	;CHANGE IN VBI
	LDA	#15	;SET BRIGHTNESS OF
	STA	DEDBRT	;PLAYER DEATH.
TIMRST	LDA	#5	;SET DEATH TIMER
	STA	TIMER	;TO 5 JIFFIES.
DEADCC	LDA	DEDBRT	;MOVE BRIGHTNESS
	STA	AUDC1	;TO DEATH SOUND VOLUME
	LDA	RANDOM	;GET RANDOM
	AND	#$1F	;DEATH SOUND
	STA	AUDF1	;FREQUENCY
	LDA	RANDOM	;GET RANDOM
	AND	#$F0	;DEATH COLOR
	ORA	DEDBRT	;ADD BRITE
	STA	COLPF1	;PUT IN LINE COLOR
	STA	COLPM1	;AND PLAYER COLOR
	LDA	TIMER	;TIMER DONE YET?
	BNE	DEADCC	;NO, GO CHANGE COLOR.
	DEC	DEDBRT	;DECREMENT BRIGHTNESS
	BPL	TIMRST	;IF MORE, GO DO IT.
	DEC	LIVES	;1 LESS LIFE
	LDA	LIVES	;GET # LIVES
	ORA	#$90	;ADD COLOR
	STA	SCOLN2+19	;AND DISPLAY!
	CMP	#$90	;ZERO LIVES?
	BNE	NOTDED	;NO!
	LDA	#GOMSG&255	;WE'RE COMPLETELY
	STA	SCDL	;DEAD, SHOW
	LDA	#GOMSG/256	;'GAME OVER'
	STA	SCDL+1	;MESSAGE
CKSTRT	LDA	CONSOL	;WAIT FOR START
	AND	#1	;KEY...
	BNE	CKSTRT	;NOT PRESSED--LOOP.
RELEAS	LDA	CONSOL	;KEY PRESSED, NOW
	AND	#1	;WAIT FOR RELEASE!
   	BEQ	RELEAS	;NOT RELEASED YET!
	LDA	#SCOLIN&255	;PUT SCORE
	STA	SCDL	;LINE BACK
	LDA	#SCOLIN/256	;IN DISPLAY
	STA	SCDL+1	;LIST...
	JMP	START	;AND START GAME!
;
;THIS SECTION PLACES PLAYER AT A RANDOM
;LOCATION IF THERE ARE MORE LIVES LEFT.
;
NOTDED	LDA	#1	;DON'T SHOW
	STA	SHOOFF	;PLAYER
NEWLOC	LDA	RANDOM	;GET RANDOM X
	AND	#$FE	;MUST BE EVEN
	CMP	#159	;AND ON SCREEN
	BCS	NEWLOC
	STA	PLOTX
CSHY	LDA	RANDOM	;GET RANDOM Y
	AND	#$7E	;MUST BE EVEN
	CMP	#85	;AND ON SCREEN
	BCS	CSHY
	STA	PLOTY
	JSR	PLOTCL
	LDY	#0
	LDA	BITSON,X
	AND	(LO),Y	;IS LOCATION ON
	CMP	COLOR1,X	;COLOR 1?
	BNE	NEWLOC	;NO, TRY AGAIN.
	JSR	PMCLR	;IT'S OK, CLEAR P/M
	LDA	PLOTX	;SAVE
	STA	PX	;THE PLAYER'S
	LDA	PLOTY	;NEW
	STA	PY	;COORDINATES.
	LDA	#0	;REDRAW THE
	STA	RDRCOL	;PLAYER'S TRACK
	LDA	HASDRN	;IN COLOR 0
	BEQ	JCTRK
	JSR	REDRAW
	LDA	INIX	;THIS PART IS
	STA	PLOTX	;NEEDED TO PLOT
	LDA	INIY	;A COLOR 1 BLOCK
	STA	PLOTY	;AT THE START OF
	JSR	PLOTCL	;THE PLAYER'S TRACK
	LDY	#0	;AFTER IT IS ERASED.
	LDA	BITOFF,X	;(NOBODY'S PERFECT!)
	AND	(LO),Y
	ORA	COLOR1,X
	STA	(LO),Y
JCTRK	LDA	#$24	;RESTORE DRAW LINE
	STA	COLPF1	;COLOR
	LDA	#0
	STA	NOCCHG
	STA	HITCLR
	STA	DEADFG
	STA	HSHORT
	JMP	CLRTRK	;AND GO START NEW TRACK.
;
;THIS ROUTINE USES THE TRACKING TABLES,
;DIR AND LGTH, TO REDRAW THE LINE THE
;PLAYER DREW.  RDRCOL INDICATES THE COLOR
;DESIRED.
;
REDRAW	LDA	INIX
	STA	REX
	LDA	INIY
	STA	REY
	LDA	#0
	STA	X
REDXLP	LDX	X
	LDA	DIR,X
	STA	REDIR
	LDA	LGTH,X
	STA	LGTHY
	LDA	#1
	STA	Y
REDYLP	LDA	#3
	STA	TIMES
TIMES3	LDA	REX
	STA	PLOTX
	LDA	REY
	STA	PLOTY
	JSR	PLOTCL
	LDY	#0
	LDA	RDRCOL
	BNE	RDC1
	LDA	BITOFF,X
	AND	(LO),Y
	STA	(LO),Y
	JMP	SETNRP
ENDRD	LDA	#0
	STA	DRAWFG
	RTS
RDC1	LDA	BITOFF,X
	AND	(LO),Y
	ORA	COLOR1,X
	STA	(LO),Y
SETNRP	DEC	TIMES
	BEQ	NXTY
	LDX	REDIR
	LDA	REX
	CLC
	ADC	XD,X
	STA	REX
	LDA	REY
	CLC
	ADC	YD,X
	STA	REY
	JMP	TIMES3
NXTY	INC	Y
	LDA	Y
	CMP	LGTHY
	BEQ	JNRD
	BCS	NXTX
JNRD	JMP	REDYLP
NXTX	INC	X
	LDA	X
	CMP	MOVIX
	BEQ	JRXLP
	BCS	ENDRD
JRXLP	JMP	REDXLP
;
;2-BYTE DECIMAL CONVERTER.  CONVERTS
;A 2-BYTE BINARY NUMBER TO A 5-BYTE
;DECIMAL NUMBER.  WILL PLACE THE
;DECIMAL NUMBER IN SCOLIN IF DESIRED
;(SLLOC DETERMINES POSITION).
;
CNVDEC	LDX	#4
	LDA	#0
CDLP	STA	DECIMAL,X
	DEX
	BPL	CDLP
	LDX	#4
CKMAG	LDA	HIWK
	CMP	HIVALS,X
	BEQ	CKM2
	BCS	SUBEM
	BCC	NOSUB
CKM2	LDA	LOWK
	CMP	LOVALS,X
	BCS	SUBEM
NOSUB	DEX
	BPL	CKMAG
	JMP	SHOWIT
SUBEM	LDA	LOWK
	SEC
	SBC	LOVALS,X
	STA	LOWK
	LDA	HIWK
	SBC	HIVALS,X
	STA	HIWK
	INC	DECIMAL,X
	JMP	CKMAG
SHOWIT	LDX	#$4
	LDY	SLLOC
	BMI	SHEND
SHOLP	LDA	DECIMAL,X
	ORA	#$D0
	STA	SCOLIN,Y
	INY
	DEX
	BPL	SHOLP
SHEND	RTS
;
;THIS ROUTINE MOVES THE STAR AROUND ON
;THE PLAYFIELD.  THE STAR IS ROTATED AND
;PLOTTED (IN A PLAYER) IN THE VBI.
;
MOVSTR	LDA	SMTIM	;TIME TO MOVE?
	BEQ	MSTR	;YES, GO DO IT
	JMP	TRYSHO	;NO, GET STICK
MSTR	LDA	STRSPD	;SET MOVEMENT TIMER
	STA	SMTIM	;WITH STAR SPEED
	LDA	STRHGT	;ADJUST P/M
	SEC		;COORDINATES TO
	SBC	#13	;MATCH PLAYFIELD
	STA	STRLY	;PLOTTING
	LDA	STRHOR	;COORDINATES.
	SEC
	SBC	#44
	STA	STRLX
	LDA	RANDOM	;WANT TO CHANGE
	CMP	#240	;THE STAR'S DIRECTION?
	BCC	SAMSTD	;NO, USE SAME.
NEWDIR	LDA	RANDOM	;GET RANDOM
	AND	#7	;DIRECTION
	JMP	DIRCHK
SAMSTD	LDA	STRDIR	;GET OLD DIRECTION.
DIRCHK	TAX		;CHECK TO SEE
	STA	TMPDIR	;IF STAR WILL
	LDA	STRLX	;BUMP INTO ANY
	CLC		;PLAYFIELD
	ADC	STRDTX,X	;OBJECT.
	STA	PLOTX
	LDA	STRLY
	CLC
	ADC	STRDTY,X
	STA	PLOTY
	JSR	PLOTCL
	LDY	#0
	LDA	BITSON,X
	AND	(LO),Y	;ANY COLLISION?
	BEQ	WAYCLR	;NO, ALL CLEAR!
	LDA	#15	;HIT SOMETHING,
	STA	BSCNT	;START BUMP SOUND AND
	BNE	NEWDIR	;GET NEW DIRECTION.
WAYCLR	LDA	PLOTX	;ADJUST STAR
	CLC		;COORDINATES
	ADC	#44	;BACK TO P/M
	STA	STRHOR	;COORDINATES
	LDA	PLOTY	;FROM PLAYFIELD.
	CLC
	ADC	#13
	STA	STRHGT
	LDA	TMPDIR	;SET DIRECTION
	STA	STRDIR
MOVESH	LDA	#3	;CHECK ALL
	STA	SHORTN	;4 SHORTS
SHMVLP	LDX	SHORTN	;GET SHORT #
	LDA	SHORTF,X	;SHORT ALIVE?
	BEQ	NXTSM	;NO
	LDA	SHORTX,X	;GET X
	STA	PLOTX	;COORDINATE
	LDA	SHORTY,X	;AND Y
	STA	PLOTY	;COORDINATE
	JSR	PLOTCL	;IS SHORT
	LDY	#0	;ON...
	LDA	BITSON,X
	AND	(LO),Y
	CMP	COLOR1,X	;COLOR1?
	BEQ	MOVEIT	;YUP!
KILLSH	LDX	SHORTN	;STOP THIS SHORT
	LDA	#0	;BY TURNING
	STA	SHORTF,X	;FUNCTION FLAG OFF
NXTSM	DEC	SHORTN	;MORE SHORTS?
	BPL	SHMVLP	;YES!
	JMP	TRYSHO	;NO.
MOVEIT	LDA	#3	;TRY 4
	STA	TRIES	;DIRECTIONS
	LDX	SHORTN	;GET SHORT #
	LDA	SHORTD,X	;AND DIRECTION
	STA	DIRSAV	;SAVE IT
TRYMOV	LDX	SHORTN	;GET SHORT #
	LDY	DIRSAV	;AND DIRECTION
	LDA	SHORTX,X	;FIND OUT
	CLC		;WHERE THE
	ADC	DIRX,Y	;SHORT WILL
     	CMP	#159	;BE NEXT
	BCS	NXTTRN	;POSITION,
	STA	PLOTX
	LDA	SHORTY,X
	CLC
	ADC	DIRY,Y
	CMP	#85
	BCS	NXTTRN
	STA	PLOTY
	JSR	PLOTCL
	LDY	#0
	LDA	BITSON,X
	AND	(LO),Y	;IS IT OVER
	CMP	COLOR1,X	;COLOR 1?
	BEQ	GOTDIR	;YES! IT'S OK!
NXTTRN	DEC	TRIES	;MORE DIRECTIONS?
	BMI	KILLSH	;NO!
	LDX	TRIES	;GET NEXT
	LDA	DIRSAV	;TRIAL DIRECTION
	CLC
	ADC	DADD,X
	AND	#3
	STA	DIRSAV
	JMP	TRYMOV	;AND TRY TO MOVE!
GOTDIR	LDX	SHORTN	;GET SHORT #
	LDA	PLOTX	;SAVE ALL
	STA	SHORTX,X	;NEW SHORT
	LDA	PLOTY	;POSITION
	STA	SHORTY,X	;AND DIRECTION
	LDA	DIRSAV	;VALUES!
	STA	SHORTD,X
	JMP	NXTSM	;DO NEXT SHORT!

;	THIS ROUTINE GENERATES NEW
;	SHORTS AT THE PROPER TIME IF
;	ANY ARE INACTIVE.

TRYSHO	LDA	SHTIM2	;READY TO START ONE?
	BEQ	TRYSH2	;YES!
	JMP	GETSTK	;NO!
TRYSH2	LDA	SHTIMI	;RESET THE
	STA	SHTIM2	;SHORT TIMER
   	LDX	#3	;SEARCH FOR
SHSCAN	LDA	SHORTF,X	;INACTIVE SHORT
	BEQ	STRTSH	;GOT ONE!!!
	DEX
	BPL	SHSCAN
	JMP	GETSTK	;NONE FOUN
STRTSH	STX	HOLDSX
STRTSX	LDA	RANDOM	;RANDOM SHORT X
	CMP	#160
	BCS	STRTSX
	STA	PLOTX
STRTSY	LDA	RANDOM	;RANDOM SHORT Y
	AND	#$7F
	CMP	#85
	BCS	STRTSY
	STA	PLOTY
	JSR	PLOTCL
	LDY	#0
	LDA	BITSON,X
	AND	(LO),Y
	CMP	COLOR1,X	;ON COLOR 1?
	BNE	STRTSX	;NO, TRY AGAIN!
	LDX	HOLDSX
	LDA	PLOTX	;SAVE ALL
	STA	SHORTX,X	;SHORT
	LDA	PLOTY	;PARAMETERS
	STA	SHORTY,X
	LDA	RANDOM
	AND	#3
	STA	SHORTD,X
	LDA	#1	;TELL PROGRAM
	STA	SHORTF,X	;SHORT IS ALIVE!
	JMP	GETSTK	;LOOP BACK
;
;SEARCH FOR FILLABLE AREA
;
;THIS SECTION SEARCHES FOR THE AREA TO
;BE FILLED.  IT IS SO COMPLICATED THAT
;EXPLANATION OF ITS FINER DETAILS
;WOULD BE ALMOST IMPOSSIBLE WITHOUT
;WRITING ANOTHER COMPLETE ARTICLE.  AT
;ANY RATE, IT WORKS.  THOSE WITH ANY
;SPECIFIC QUESTIONS SHOULD WRITE ME,
;CARE OF A.N.A.L.O.G.
;
SEARCH	LDA	#1
	STA	FILLON
	LDA	#0
	STA	D
	LDA	STRHOR
	SEC
	SBC	#44
	STA	SX
	LDA	STRHGT
	SEC
	SBC	#13
	STA	SY
FINDCL	LDX	D
	LDA	SX
	CLC
	ADC	SXD,X
	STA	SX
	STA	PLOTX
	LDA	SY
	CLC
	ADC	SYD,X
	STA	SY
	STA	PLOTY
	JSR	PLOTCL
	LDY	#0
	LDA	(LO),Y
	AND	BITSON,X
	CMP	COLOR1,X
	BEQ	FINDC2
	CMP	COLOR2,X
	BNE	FINDCL
	LDA	#0
	STA	TD
	JMP	FOUND2
FINDC2	LDA	D
	STA	TD
	JSR	DECD
FC2A	JSR	SRCHLC
	CMP	COLOR1,X
	BNE	FC2B
	JSR	GRABEM
	JMP	FINDC2
FC2B	CMP	COLOR2,X
	BNE	FC2C
	JSR	GRABEM
	JMP	OUTLIN
FC2C	JSR	INCD
	JMP	FC2A
FOUND2	LDA	#0
	STA	TRIES
	JSR	DECD
FND2A	JSR	SRCHLC
	CMP	COLOR2,X
	BNE	FND2B
	JSR	GRABEM
	JMP	FOUND2
FND2B	LDA	TRIES
	CLC
	ADC	#1
	STA	TRIES
	CMP	#3
	BEQ	FINDC1
	JSR	INCD
	JMP	FND2A
FINDC1	LDA	D
	STA	TD
	JSR	DECD
FC1A	JSR	SRCHLC
	CMP	COLOR1,X
	BNE	FC1B
	JSR	GRABEM
	JMP	FINDC2
FC1B	JSR	INCD
	JMP	FC1A
OUTLIN	JSR	PLSXSY
	LDA	#0
	STA	TRIES
OUTLA	JSR	SRCHLC
	CMP	COLOR1,X
	BNE	OUTLB
	JSR	GRABEM
	JMP	OUTLIN
OUTLB	LDA	TRIES
	CLC
	ADC	#1
	STA	TRIES
	CMP	#4
	BEQ	OUTLD
	JSR	INCD
	JMP	OUTLA
OUTLD	JSR	LOCTXY
OUTLD2	CMP	COLOR2,X
	BNE	OUTLE
	JSR	FILL
	LDA	#0
	STA	FILLON
	RTS
OUTLE	JSR	INCD
	JSR	SRCHLC
	JMP	OUTLD2
SRCHLC	LDX	TD
	LDA	SX
	CLC
	ADC	SXD,X
	STA	TX
	STA	PLOTX
	LDA	SY
	CLC
	ADC	SYD,X
	STA	TY
	STA	PLOTY
LOCTXY	LDA	PLOTX
	CMP	#159
	BCS	NOREAD
	LDA	PLOTY
	CMP	#85
	BCS	NOREAD
	JSR	PLOTCL
	LDY	#0
	LDA	(LO),Y
	AND	BITSON,X
	RTS
NOREAD	LDA	#0
	LDX	#0
	RTS
GRABEM	LDA	TD
	STA	D
	LDA	TX
	STA	SX
	LDA	TY
	STA	SY
	RTS
INCD	LDA	TD
	CLC
	ADC	#1
	AND	#3
	STA	TD
	RTS
DECD	LDA	TD
	SEC
	SBC	#1
	AND	#3
	STA	TD
	RTS
PLSXSY	LDA	SX
	STA	PLOTX
	CMP	MAXX
	BCC	TMINX2
	STA	MAXX
	JMP	CKYMM2
TMINX2	CMP	MINX
	BCS	CKYMM2
	STA	MINX
CKYMM2	LDA	SY
	STA	PLOTY
	CMP	MAXY
	BCC	TMINY2
	STA	MAXY
	JMP	ENDMM2
TMINY2	CMP	MINY
	BCS	ENDMM2
	STA	MINY
ENDMM2	JSR	PLOTCL
	LDY	#0
	LDA	BITOFF,X
	AND	(LO),Y
	ORA	COLOR2,X
	STA	(LO),Y
	RTS
;
;FILL ROUTINE
;
;AS WITH THE 'SEARCH' SUBROUTINE, THE
;FILL SUBROUTINE IS FAR TOO COMPLEX TO
;EXPLAIN HERE.  THIS FILL IS ENTIRELY
;DIFFERENT FROM THE SYSTEM'S FILL
;ROUTINE, AS IT WILL FILL ANY SHAPE
;THAT IS OUTLINED IN COLOR 2.
;
FILL	LDA	#0	;TURN OFF
	STA	AUDC2	;SOUND CHANNELS
	STA	AUDC3	;2 AND 3.
	LDA	MAXY	;INITIALIZE
	SEC		;THE FILL
	SBC	MINY	;SOUND
	STA	FILFRQ	;FREQUENCY.
	LDA	MINX
	SEC
	SBC	#1
	STA	MINX
	STA	FX
	LDA	MINY
	STA	FY
	SEC
	SBC	#1
	STA	MINY
	LDA	MAXX
	CLC
	ADC	#1
	STA	MAXX
	LDA	MAXY
	CLC
	ADC	#1
	STA	MAXY
	LDA	#0
	STA	SCTALY
CLRC2T	LDA	#0
	STA	C2TALY
LOCLP1	JSR	LOCATE
	CMP	#2
	BNE	LOCLP1
LOCLP2	INC	C2TALY
	JSR	LOCATE
	CMP	#2
	BEQ	LOCLP2
	AND	#1
	BNE	CLRC2T
	LDA	C2TALY
	CMP	#1
	BEQ	FILLIT
	JSR	LOCPRV
	BEQ	CLRC2T
FILLIT	LDA	FX
	STA	PLOTX
	LDA	FY
	STA	PLOTY
	JSR	PLOTCL
	LDY	#0
	LDA	(LO),Y
	ORA	COLOR3,X
	STA	(LO),Y
	INC	SCTALY
	JSR	LOCATE
	CMP	#0
	BEQ	FILLIT
	AND	#1
	BNE	CLRC2T
	LDA	#1
	STA	C2TALY
FOLLOW	JSR	LOCATE
	CMP	#0
	BEQ	LOCLP3
	AND	#1
	BNE	CLRC2T
	INC	C2TALY
	JMP	FOLLOW
LOCLP3	LDA	C2TALY
	CMP	#1
	BNE	LOCLP4
	JMP	CLRC2T
LOCLP4	JSR	LOCPRV
	CMP	BITSON,X
	BEQ	FILLIT
	JMP	CLRC2T
LOCATE	LDA	FX
	CLC
	ADC	#1
	STA	FX
	CMP	MAXX
	BNE	STOFX
	LDA	CURLO
	CLC
	ADC	SCTALY
	STA	CURLO
	LDA	CURHI
	ADC	#0
	STA	CURHI
	LDA	#0
	STA	SCTALY
	LDA	MINX
	STA	FX
	LDA	#0
	STA	C2TALY
	LDA	#$86
	STA	AUDC1
	LDA	FILFRQ
	STA	AUDF1
	BEQ	NOFFDC
	DEC	FILFRQ
NOFFDC	LDA	FY
	CLC
	ADC	#1
	STA	FY
	CMP	MAXY
	BEQ	FILEND
	LDA	FX
	CMP	MINX
	BNE	STOFX
	PLA
	PLA
	JMP	CLRC2T
FILEND	PLA
	PLA
	RTS
STOFX	LDA	FX
	STA	PLOTX
	LDA	FY
	STA	PLOTY
	JSR	PLOTCL
	LDY	#0
	LDA	BITSON,X
	AND	(LO),Y
	CMP	COLOR2,X
	BNE	NOTC2
	LDA	BITSON,X
	ORA	(LO),Y
	STA	(LO),Y
	INC	SCTALY
	LDA	#2
	RTS
NOTC2	CMP	COLOR1,X
	BNE	NOTC1
	LDA	#1
	RTS
NOTC1	CMP	#0
	BNE	C3
	RTS
C3	LDA	#3
	RTS
LOCPRV	LDA	FX
	STA	PLOTX
	LDA	FY
	SEC
	SBC	#1
	CMP	MINY
	BEQ	NOLOCP
	STA	PLOTY
	JSR	PLOTCL
	LDY	#0
	LDA	BITSON,X
	AND	(LO),Y
	RTS
NOLOCP	LDA	#0
	LDX	#0
	RTS
;
;VBI ROUTINE
;
INTRPT	LDA	KEY	;IS SPACE BAR
	CMP	#$21	;PRESSED?
	BNE	NOPRES	;NO, CHECK FOR PAUSE.
	LDA	#$FF	;CLEAR OUT
	STA	KEY	;KEY CODE,
	LDA	PAUSE	;COMPLEMENT
	EOR	#$FF	;THE PAUSE
	STA	PAUSE	;FLAG.
NOPRES	LDA	PAUSE	;ARE WE PAUSED?
	BEQ	NOPAUS	;NO!
	JMP	XITVBV	;PAUSED, NO VBI!
NOPAUS	LDA	BSCNT	;MORE BUMP SOUND?
	BMI	NOBS	;NO, PROCESS TIMER.
	ORA	#$A0	;MIX VOLUME WITH
	STA	AUDC4	;PURE TONE,
	LDA	#$80	;SET UP BUMP
	STA	AUDF4	;SOUND FREQUENCY
 	DEC	BSCNT	;AND DECREMENT COUNT.
NOBS	LDA	TIMER	;TIMER DOWN TO ZERO?
	BEQ	NODEC	;YES, DON'T DECREMENT.
	DEC	TIMER	;DECREMENT TIMER.
NODEC	LDA	SHTIM2
	BEQ	NODEC2
	DEC	SHTIM1
	BNE	NODEC2
	DEC	SHTIM2
NODEC2	LDA	FILLON	;ARE WE FILLING?
	BEQ	NOFILL	;NO, DO REST OF VBI.
	JMP	XITVBV	;YES, EXIT VBI
NOFILL	LDA	#0	;CLEAR OUT
	STA	DEADFG	;DEAD FLAG
	STA	HSHORT	;AND SHORT HIT.
	LDA	P1PL	;HAS PLAYER 1
	AND	#$0C	;HIT PLAYER 2/3?
	BEQ	NOHITS	;NO, IT'S OK
	INC	HSHORT	;YES!!!
NOHITS	LDA	P1PL	;HAS PLAYER 1
	AND	#$01	;HIT PLAYER 0?
	BEQ	NOHITP	;NO!
	INC	DEADFG	;YES!!!
NOHITP	LDA	P0PF	;HAS PLAYER 0
	AND	#$02	;HIT COLOR 2?
	BEQ	NOHITL	;NO!
	INC	DEADFG	;YES!!!
NOHITL	STA	HITCLR	;CLEAR COLLISION.
	LDA	MOVTIM	;MOVEMENT TIMER ZERO?
	BEQ	NOMDEC	;YES, DON'T DECREMENT.
	DEC	MOVTIM	;DECREMENT TIMER.
NOMDEC	LDA	SMTIM	;STAR MOVE TIMER ZERO?
	BEQ	NMTDEC	;YES, DON'T DECREMENT.
	DEC	SMTIM	;DECREMENT TIMER.
NMTDEC	LDA	STARCT	;STAR ROT. TIMER ZERO?
	BEQ	STAROT	;YES, ROTATE STAR!
	DEC	STARCT	;DECREMENT TIMER
	JMP	VBREST	;AND SKIP ROTATION.
STAROT	LDA	#1	;SET ROT. TIMER
	STA	STARCT	;TO 1
	LDA	STRPOS	;INCREMENT
	CLC		;STAR ROTATION
	ADC	#1	;COUNTER,
	CMP	#7	;ALLOW ONLY 0-6.
	BNE	STOSTP	;ROT. COUNT OK
	LDA	#0	;ZERO ROT. COUNTER.
STOSTP	STA	STRPOS	;SAVE ROT. POS.
VBREST	LDY	STRPOS	;THIS SECTION
	LDX	STRHGT	;DRAWS THE STAR
	LDA	#0	;IN PLAYER 0
	STA	PL0-1,X	;MEMORY USING
	STA	PL0+8,X	;THE TABLES
	LDA	STARB1,Y	;'STARB1' THRU
	STA	PL0,X	;'STARB8'.
	LDA	STARB2,Y
	STA	PL0+1,X
	LDA	STARB3,Y
	STA	PL0+2,X
	LDA	STARB4,Y
	STA	PL0+3,X
	LDA	STARB5,Y
	STA	PL0+4,X
	LDA	STARB6,Y
	STA	PL0+5,X
	LDA	STARB7,Y
	STA	PL0+6,X
	LDA	STARB8,Y
	STA	PL0+7,X
	LDA	STRHOR	;SET STAR'S
	STA	HPOSP0	;HORIZ. POS.
	LDA	SHOOFF	;OK TO SHOW PLAYER?
	BNE	ENDVBI	;NO, EXIT VBI
	LDA	PX	;SET PLAYER'S
	CLC		;HORIZONTAL
	ADC	#47	;POSITION
	STA	HPOSP1
	LDA	PY	;DRAW PLAYER
	CLC		;IN PLAYER 3
	ADC	#$10	;MEMORY
	TAX
	LDA	#0
	STA	PL1-3,X
	STA	PL1-2,X
	STA	PL1+2,X
	STA	PL1+3,X
	LDA	#$40
	STA	PL1-1,X
	STA	PL1+1,X
	LDA	#$A0
	STA	PL1,X
	LDA	NOCCHG	;COLOR CHANGE OK?
	BNE	ENDVBI	;NO, EXIT VBI
	INC	COLPM1	;YES, CYCLE THE COLOR.

;	THE FOLLOWING ROUTINE USES TWO
;	PLAYERS (2 & 3) TO DISPLAY THE
;	"SHORTS."  EACH PLAYER IS USED
;	TO SHOW 2 SHORTS, SO SOME
;	FLICKER MAY BE OBSERVED.

ENDVBI	INC	SHFLIP	;TOGGLE FLIP
	LDA	SHFLIP	;MASK FLIP
	LSR	A	;TO EITHER
	AND	#1	;0 OR 1
	TAY		;PUT IN Y
	LDA	CPYSTN,Y	;AND GET IMAGE
	STA	CPYST	;TO USE (+/X)
	LDA	SHFLIP	;GET FLIP,
	AND	#1	;MASK AND
	TAY		;PUT IN Y
	LDA	#PL3/256	;PUT PLAYER 3
	STA	DESTHI	;IN DESTINATION
	LDA	#PL3&255	;ADDRESS
	STA	DESTLO	;HI & LO
	LDA	#1	;SET DEST #
	STA	DESTNM
	LDA	SHSTRT,Y	;GET START
	STA	VBXHLD	;SHORT #
SHORLP	LDA	#0	
	LDX	DESTNM
	LDY	SHYHLD,X	;GET LAST INDEX
	LDX	#4	;NOW ERASE
ERSSHO	STA	(DESTLO),Y	;PREVIOUS
	INY		;SHORT
	DEX
	BPL	ERSSHO
	LDX	VBXHLD
	LDA	SHORTF,X	;SHORT ALIVE?
	BEQ	NXTSHO	;NO!
	LDA	SHORTX,X	;GET SHORT'S
	LDY	SHORTY,X	;COORDINATES,
	CLC
	ADC	#46
	LDX	DESTNM
	STA	HPOSP2,X	;SET HORIZ. POS.
	TYA
	CLC
	ADC	#14
	STA	SHYHLD,X	;AND VERTICAL POS.
	TAY
	LDX	CPYST
	LDA	#4	;NOW COPY
	STA	CPYCNT	;SHORT IMAGE
SHOCOP	LDA	SHOIMG,X	;TO THE
	STA	(DESTLO),Y	;PLAYER
	INY
	DEX
	DEC	CPYCNT
	BPL	SHOCOP
NXTSHO	DEC	DESTNM	;MORE?
	BMI	VBEND	;NO, EXIT!
	LDA	DESTLO	;POINT TO
	SEC		;NEXT PLAYER
	SBC	#128
	STA	DESTLO
	LDA	DESTHI
	SBC	#0
	STA	DESTHI
	INC	VBXHLD
	JMP	SHORLP	;AND LOOP BACK.

VBEND	JMP	XITVBV	;DONE WITH VBI!
;
;DATA
;
DLIST	DB	$70,$70,$70
	DB	$4D,DISP&255,DISP/256
	DB	$D,$D,$D,$D,$D,$D,$D,$D,$D,$D
	DB	$D,$D,$D,$D,$D,$D,$D,$D,$D,$D
	DB	$D,$D,$D,$D,$D,$D,$D,$D,$D,$D
	DB	$D,$D,$D,$D,$D,$D,$D,$D,$D,$D
	DB	$D,$D,$D,$D,$D,$D,$D,$D,$D,$D
	DB	$D,$D,$D,$D,$D,$D,$D,$D,$D,$D
	DB	$D,$D,$D,$D,$D,$D,$D,$D,$D,$D
	DB	$D,$D,$D,$D,$D,$D,$D,$D,$D,$D
	DB	$D,$D,$D,$D,$D,$20,$46
SCDL	DW	SCOLIN
	DB	$46
	DW	SCOLN2
	DB	$41,DLIST&255,DLIST/256

TITLDL	DB	$70,$70,$70,$70,$70,$70
	DB	$70,$70,$70,$30,$46
	DW	MAGMSG
	DB	$70,$47
	DW	TITLE
	DB	$30,$46
	DW	AUTHOR
	DB	$70,$70,$30,$46
	DW	STMSG
	DB	$41
	DW	TITLDL

SCOLIN	DB	CT,CG,CT,CCOL,0,0,0,0,0,0
	DB	0,CC,CU,CR,CCOL,0,0,0,0,0
SCOLN2	DB	CL,CV,CCOL,0,0,0,CS,CC,CO
	DB	CR,CE,CCOL,0,0,0,0,0,0,0,0
GOMSG	DB	0,0,0,0,0,CG,CA,CM,CE,0
	DB	0,CO,CV,CE,CR,0,0,0,0,0
MAGMSG	DB	0,0,$21,$2E,$21,$2C,$2F,$27
	DB	0,$23,$2F,$2D,$30,$35
	DB	$34,$29,$2E,$27,0,0
TITLE	DB	0,0,0,$66,$69,$6C,$6C,$47
	DB	$65,$72,0,$75,$70,$41,0
	DB	$69,$69,0,0,0
AUTHOR	DB	0,0,0,$A2,$B9,0,0,$B4
	DB	$AF,$AD,0,$A8,$B5,$A4,$B3,$AF
	DB	$AE,0,0,0
STMSG	DB	0,0,0,0,$F0,$F2,$E5,$F3
	DB	$F3,0,0,$F3,$F4,$E1,$F2,$F4
	DB	0,0,0,0

;
;LEVEL TABLES
;
TGTLO	DB	64,16,224,40,248,212,16,4
	DB	248,224,212,224,68,168,112,212
TGTHI	DB	31,39,46,35,42,48,39,41,42
	DB	46,48,46,47,47,48,48
STARSP	DB	4,4,4,3,3,3,2,2,2,2,2,1,1
	DB	1,1,1
KILLFG	DB	0,0,1,0,1,1,0,1,1,1,1,0,0
	DB	1,1,1
SHTIME	DB	7,7,7,6,6,6,5,5,5,4,4,4,3
	DB	3,2,1

SHSTRT	DB	0,2
SHYHLD	DS	2
SHOIMG	DB	$88,$50,$20,$50,$88
	DB	$20,$20,$F8,$20,$20
CPYSTN	DB	4,9
DADD	DB	$FF,2,1
DIRX	DB	0,1,0,$FF
DIRY	DB	$FF,0,1,0
SHORTX	DS	4
SHORTY	DS	4
SHORTF	DS	4
SHORTD	DS	4

ZERO1	DB	0
SCORE	DB	0,0,0,0,0,0
SLLOC	DB	0
CURLO	DB	0
CURHI	DB	0
LEVEL	DB	0
PAUSE	DB	0
HASDRN	DB	0
LOWK	DB	0
HIWK	DB	0
SCTALY	DB	0
LIVES	DB	0
;
;STAR PLAYER-MISSILE IMAGES
;
STARB1	DB	$81,$40,$20,$10,$08,$04,$02
STARB2	DB	$42,$43,$20,$10,$08,$04,$C2
STARB3	DB	$24,$24,$13,$10,$08,$C8,$24
STARB4	DB	$18,$18,$1C,$1F,$F8,$38,$18
STARB5	DB	$18,$18,$38,$F8,$1F,$1C,$18
STARB6	DB	$24,$24,$C8,$08,$10,$13,$24
STARB7	DB	$42,$C2,$04,$08,$10,$20,$43
STARB8	DB	$81,$02,$04,$08,$10,$20,$40

STARCT	DB	0
STRPOS	DB	0
STRHGT	DB	0
STRHOR	DB	0
STRLX	DB	0
STRLY	DB	0
TMPDIR	DB	0
STRDIR	DB	0
STRDTX	DB	1,1,0,255,255,255,0,1
STRDTY	DB	0,1,1,0,1,255,255,255
STRSPD	DB	4
COLOR1	DB	$40,$10,$04,$01
COLOR2	DB	$80,$20,$08,$02
COLOR3	DB	$C0,$30,$0C,$03
BITSON	DB	$C0,$30,$0C,$03
BITOFF	DB	$3F,$CF,$F3,$FC
BXSTRT	DB	0,158,158,0
BYSTRT	DB	0,0,84,84
BXINC	DB	1,0,255,0
BYINC	DB	0,1,0,255
BORCNT	DB	159,85,159,85
BORNUM	DB	0
BDINCX	DB	0
BDINCY	DB	0
BDCNT	DB	0
PXWC	DB	0
PYWC	DB	0
SHOOFF	DB	0
CKX	DB	0
CKY	DB	0
INIX	DB	0
INIY	DB	0
MINX	DB	0
MINY	DB	0
MAXX	DB	0
MAXY	DB	0
REX	DB	0
REY	DB	0
X	DB	0
Y	DB	0
SX	DB	0
SY	DB	0
TX	DB	0
TY	DB	0
FX	DB	0
FY	DB	0
TD	DB	0
D	DB	0
BSCNT	DB	0
FILFRQ	DB	0
TRIES	DB	0
FILLON	DB	0
C2TALY	DB	0
NOCCHG	DB	0
DEDBRT	DB	0
STKHLD	DB	0
RDRCOL	DB	0
REDIR	DB	0
LGTHY	DB	0
TIMES	DB	0
CKV	DB	0
CKVX	DB	0
DRAWFG	DB	0
MOVIX	DB	0
XD	DB	0,0,0,0
	DB	0,0,0,1
	DB	0,0,0,255
	DB	0,0,0,0
YD	DB	0,0,0,0
	DB	0,0,0,0
	DB	0,0,0,0
	DB	0,1,255,0
SXD	DB	0,1,0,255
SYD	DB	255,0,1,0
DECIMAL	DB	0,0,0,0,0
ZERO2	DB	0
HIVALS	DB	0,0,0,3,39
LOVALS	DB	1,10,100,232,16
DIR	DS	256
LGTH	DS	256

	END	$6000