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Copy pathblast.asm
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blast.asm
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;BLAST!
;
*= $2000
;
CHARSET
.BYTE $00,$00,$00,$00,$00,$00,$00,$00
.BYTE $00,$1C,$1C,$1C,$1C,$00,$1C,$1C
.BYTE $00,$00,$3F,$3F,$3F,$3F,$3F,$3F
.BYTE $00,$00,$F8,$FC,$3E,$3F,$3F,$3E
.BYTE $3F,$3F,$3F,$3F,$3F,$3F,$3F,$3F
.BYTE $FC,$FC,$3E,$3F,$3F,$3E,$FC,$F8
.BYTE $00,$00,$FF,$FF,$FF,$FF,$FF,$FF
.BYTE $00,$00,$03,$07,$0F,$1F,$3F,$3F
.BYTE $00,$00,$F0,$F8,$FC,$FE,$3F,$3F
.BYTE $FF,$FF,$3F,$3F,$3F,$3F,$3F,$3F
.BYTE $00,$00,$0F,$1F,$3C,$3C,$1F,$0F
.BYTE $00,$00,$FF,$FF,$00,$00,$C0,$F0
.BYTE $00,$00,$0F,$0F,$0F,$0F,$0F,$0F
.BYTE $00,$00,$3F,$3F,$0F,$0F,$0F,$0F
.BYTE $00,$00,$FC,$FC,$F0,$F0,$F0,$F0
.BYTE $00,$00,$F0,$F0,$F0,$F0,$F0,$F0
.BYTE $00,$7F,$63,$63,$63,$67,$67,$7F
.BYTE $00,$1C,$0C,$0C,$0C,$1E,$1E,$1E
.BYTE $00,$7F,$03,$03,$7F,$60,$60,$7F
.BYTE $00,$7E,$06,$06,$7F,$07,$07,$7F
.BYTE $00,$70,$70,$70,$70,$77,$7F,$07
.BYTE $00,$7F,$60,$60,$7F,$07,$07,$7F
.BYTE $00,$7E,$66,$60,$7F,$63,$63,$7F
.BYTE $00,$7F,$67,$07,$0E,$1C,$1C,$1C
.BYTE $00,$3E,$36,$36,$7F,$77,$77,$7F
.BYTE $00,$7F,$63,$63,$7F,$07,$07,$07
.BYTE $00,$1C,$1C,$1C,$00,$1C,$1C,$1C
.BYTE $FC,$FE,$FF,$FF,$FF,$FF,$FE,$FC
.BYTE $0F,$0F,$00,$00,$0F,$0F,$0F,$0F
.BYTE $0F,$0F,$0F,$0F,$0F,$0F,$0F,$0F
.BYTE $F0,$F0,$F0,$F0,$F0,$F0,$F0,$F0
.BYTE $F0,$F0,$00,$00,$F0,$F0,$F0,$F0
.BYTE $00,$00,$08,$1C,$14,$55,$77,$5D
.BYTE $00,$3E,$36,$36,$7F,$77,$77,$77
.BYTE $00,$7E,$66,$66,$7F,$73,$73,$7F
.BYTE $00,$7F,$67,$60,$60,$60,$63,$7F
.BYTE $00,$7E,$63,$63,$73,$73,$73,$7E
.BYTE $00,$7F,$60,$60,$7F,$70,$70,$7F
.BYTE $00,$7F,$60,$60,$7F,$70,$70,$70
.BYTE $00,$7F,$63,$60,$70,$77,$73,$7F
.BYTE $00,$36,$36,$36,$7F,$77,$77,$77
.BYTE $00,$18,$18,$18,$1C,$1C,$1C,$1C
.BYTE $00,$03,$03,$03,$07,$67,$67,$7F
.BYTE $00,$33,$33,$33,$7C,$73,$73,$73
.BYTE $00,$30,$30,$30,$70,$70,$70,$7F
.BYTE $00,$7F,$4B,$4B,$6B,$6B,$6B,$6B
.BYTE $00,$73,$7B,$6F,$77,$77,$77,$77
.BYTE $00,$7F,$63,$63,$67,$67,$67,$7F
.BYTE $00,$7F,$63,$63,$7F,$70,$70,$70
.BYTE $00,$7F,$63,$63,$63,$63,$6F,$7C
.BYTE $00,$7E,$66,$66,$7F,$73,$73,$73
.BYTE $00,$7F,$60,$60,$7F,$03,$03,$7F
.BYTE $00,$7F,$1F,$1C,$1C,$1C,$1C,$1C
.BYTE $00,$63,$63,$63,$73,$73,$73,$7F
.BYTE $00,$63,$63,$63,$77,$76,$76,$7E
.BYTE $00,$43,$43,$43,$6B,$6B,$6B,$7F
.BYTE $00,$67,$67,$67,$3C,$73,$73,$73
.BYTE $00,$63,$63,$63,$7F,$1C,$1C,$1C
.BYTE $00,$7F,$73,$03,$7F,$70,$73,$7F
.BYTE $00,$1E,$18,$18,$18,$18,$1E,$00
.BYTE $00,$40,$60,$30,$18,$0C,$06,$00
.BYTE $00,$78,$18,$18,$18,$18,$78,$00
.BYTE $00,$08,$1C,$36,$63,$00,$00,$00
.BYTE $00,$00,$00,$00,$00,$00,$FF,$00
;
; Zero page equates
;
ADDER = $80
PTR = $82
EXPCOUNT = $89
ALCOUNT = $8A
SHIPX = $8B
MOTHERX = $8C
MOTHERDX = $8D
FORCEY = $8E
ROUND = $8F
XTAB = $90
YTAB = $9C
DXTAB = $A8
DYTAB = $B4
DSTAB = $C0 ;STATUS
;
; OS equates
;
STRIG0 = $0284
HPOSP0 = $D000
M0PF = $D000
P0PF = $D004
HITCLR = $D01E
AUDF1 = $D200 ;Force field
AUDC1 = $D201
AUDF2 = $D202 ;Laser
AUDC2 = $D203
AUDF3 = $D204 ;Monster death
AUDC3 = $D205
AUDF4 = $D206 ;Needle falling
AUDC4 = $D207
RANDOM = $D20A
;
SCREEN = $1000
;
; game screen dl
;
MAINDL
.BYTE $70,$50,$4D
.WORD SCREEN
.BYTE $0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$0D,$0D
.BYTE $0D,$0D,$8D,0
.BYTE $47
.WORD SCORELN
.BYTE $41
.WORD MAINDL
;
; "GAME OVER" display list
;
GODL
.BYTE $70,$70,$70,$70
.BYTE $70,$70,$70,$70
.BYTE $70,$70,$70,$70
.BYTE $47
.WORD GOLN
.BYTE $41
.WORD GODL
;
; Title page dl
;
TITLEDL
.BYTE $70,$70,$F0
.BYTE $47
.WORD TITLEPG-20
.BYTE $07,$70,$06,$70
.BYTE $06,$70,$70,$70
.BYTE $70,$70,$07,$70
.BYTE $70,$07,$70
.BYTE $70,$07,$41
.WORD TITLEDL
;
; Score line
; (at bottom, in graphics 2)
; Ships at +7
; score at +17
;
SCORELN
.SBYTE "BLAST! @@ SCORE:000"
;
; Game over
;
GOLN .SBYTE " GAME OVER "
;
; Prelim. title page
; Last at +46, high at +55
; Speed at +72, skill at +92
;
.BYTE 0,0,0,0,2,3,2,0,7,8,10,11,13,14,12,15,0,0,0,0
TITLEPG .BYTE 0,0,0,0,4,5,4,6,4,9,2,27,29,30,28,31,0,0,0,0
.SBYTE " BY STEVEN GRIMM "
.SBYTE " LAST:000 HIGH:000 "
.SBYTE " option slow "
.SBYTE " select easy "
.SBYTE "press start to begin"
;
; Y tables for bitmap routine
;
TABLO
.BYTE 0,40,80,120,160,200,240
.BYTE 24,64,104,144,184,224
.BYTE 8,48,88,128,168,208,248
.BYTE 32,72,112,152,192,232
.BYTE 16,56,96,136,176,216
.BYTE 0,40,80,120,160,200,240
.BYTE 24,64,104,144,184,224
.BYTE 8,48,88,128,168,208,248
.BYTE 32,72,112,152,192,232
.BYTE 16,56,96,136,176,216
.BYTE 0,40,80,120,160,200,240
.BYTE 24,64,104,144,184,224
.BYTE 8,48,88,128,168,208,248
.BYTE 32,72,112,152,192,232
.BYTE 16,56,96,136,176,216
TABHI
.BYTE 0,0,0,0,0,0,0
.BYTE 1,1,1,1,1,1
.BYTE 2,2,2,2,2,2,2
.BYTE 3,3,3,3,3,3
.BYTE 4,4,4,4,4,4
.BYTE 5,5,5,5,5,5,5
.BYTE 6,6,6,6,6,6
.BYTE 7,7,7,7,7,7,7
.BYTE 8,8,8,8,8,8
.BYTE 9,9,9,9,9,9
.BYTE 10,10,10,10,10,10,10
.BYTE 11,11,11,11,11,11
.BYTE 12,12,12,12,12,12,12
.BYTE 13,13,13,13,13,13
.BYTE 14,14,14,14,14,14
WIDTH = $84
;
; Bitmap routine for Atari
;
; Enter:
; .x,.y screen coords to plot at
; PTR pointer to bitmap:
; height
; width
; pointer to shift 0
; pointer to shift 1
; pointer to shift 2
; pointer to shift 3
; start of data
;
PLOTMAP
TXA
LSR A
LSR A
CLC
ADC TABLO,Y
STA ADDER
LDA TABHI,Y
ADC #>SCREEN
STA ADDER+1
TXA
AND #3
ASL A
ADC #2
PHA
LDY #0
LDA (PTR),Y
TAX
INY
LDA (PTR),Y
STA WIDTH
PLA
TAY
LDA (PTR),Y
PHA
INY
LDA (PTR),Y
STA PTR+1
PLA
STA PTR
CLV
BVC ?PM1.5
?PM1 LDA ADDER
CLC
ADC #40
STA ADDER
BCC ?PM1.5
INC ADDER+1
?PM1.5 LDY #0
?PM2 LDA (PTR),Y
STA (ADDER),Y
INY
CPY WIDTH
BCC ?PM2
TYA
CLC
ADC PTR
STA PTR
BCC ?PM3
INC PTR+1
?PM3 DEX
BNE ?PM1
RTS
;
; Erase bitmap - cheating
; method
;
ERASEBM LDA ?PM2
PHA
LDA ?PM2+1
PHA
LDA #$A9 ;lda imm
STA ?PM2
LDA #0
STA ?PM2+1
JSR PLOTMAP
PLA
STA ?PM2+1
PLA
STA ?PM2
RTS
PLAYER0 = $3200
PLAYER1 = $3280
PLAYER2 = $3300
PLAYER3 = $3380
;
; Player-missile routines.
; Includes player-missile init-
; ialization and startup.
;
PMINIT LDA #[>PLAYER0]-2
STA $D407 ;pmbase
LDX #0
TXA
?PMI1 STA PLAYER0,X
STA PLAYER2,X
STA PLAYER0-$80,X
INX
BNE ?PMI1
LDA #0
STA $D008 ;sizep0
STA $D00A ;sizep2
STA $D00B ;sizep3
LDA #192
STA $D00C ;sizem
LDA #1
STA $D009 ;sizep1
LDA #48
STA $D002 ;hposp2
LDA #200
STA $D003 ;hposp3
LDA #120
STA $D001 ;hposp1
LDA #124
STA $D007 ;hposm3
LDA #8
STA 704
LDA #$88
STA 705
LDA #$CC
STA 706
STA 707
RTS
;
; Put up player's ship.
;
PUTSHIP
LDY #0
?PS2 LDA PLAYER,Y
STA PLAYER0,X
INX
INY
CPY #8
BCC ?PS2
RTS
;
; Move mother ship one unit.
; X position of center is in
; MOTHERX.
;
MOVEMOM LDA MOTHERX
CLC
ADC MOTHERDX
STA MOTHERX
CMP #10
BCS ?MMOM1
LDA #1
STA MOTHERDX
?MMOM1 CMP #144
BCC ?MMOM2
LDA #-1
STA MOTHERDX
?MMOM2 LDA MOTHERX
CLC
ADC #44
STA $D007 ;hposm3
SEC
SBC #4
STA $D001 ;hposp1
JMP ALIEN
;
; Plot mother ship in player 1
; with y-coord .y
;
PLOTMOM
TYA
PHA
LDX #0
?PMOM1 LDA MOTHER,X
STA PLAYER1,Y
INX
INY
CPX #7
BCC ?PMOM1
PLA
CLC
ADC #2
TAY
LDA #0
STA MISSILES,Y
LDA #$C0
STA MISSILES+1,Y
RTS
;
; Plot left and right force
; field generators in players
; at .y
;
PLOTGEN
LDX #0
?PGEN1 LDA LEFTGEN,X
STA PLAYER2,Y
LDA RIGHTGEN,X
STA PLAYER3,Y
INX
INY
CPX #10
BCC ?PGEN1
RTS
;
; Plot up force field in color
; .a and at FORCEY
;
PLOTFIELD
PHA
LDY FORCEY
LDA TABLO,Y
STA ADDER
LDA TABHI,Y
CLC
ADC #>SCREEN
STA ADDER+1
LDY #38
PLA
?PFIELD1 STA (ADDER),Y
DEY
BNE ?PFIELD1
RTS
;
; Put explosion number .x into
; player's ship area
;
PUTEXP
LDA TIMES7,X
TAX
LDY #94
?PX1 LDA SEXPLODE,X
STA PLAYER0,Y
INX
INY
CPY #101
BCC ?PX1
RTS
TIMES7 .BYTE 0,7,14,21,28,35,42,49,56,63
.LOCAL
;
; Movement routines for the
; monsters.
;
?TEMP .BYTE 0
NEEDLEX .BYTE 0
NEEDLEY .BYTE 0
NEEDLEF .BYTE 0
?YT = $84
?XT = $85
;
; Move monster number .x
;
MOVE1
LDA XTAB,X
STA ?XT
LDA YTAB,X
STA ?YT
LDA DYTAB,X
BMI ?M11
INC ?YT
LDA ?YT
CMP #83 ;bottom
BNE ?M12
LDA #-1
STA DYTAB,X
BNE ?M12
?M11 DEC ?YT
LDA ?YT
CMP FORCEY ;check field
BNE ?M12
LDA #1
STA DYTAB,X
?M12 LDA ?XT
CLC
ADC DXTAB,X
STA ?XT
CMP #8
BNE ?M13
LDA #1
STA DXTAB,X
?M13 CMP #142 ;rt side
BCC ?M1X
LDA #-1
STA DXTAB,X
?M1X LDA ?YT
STA YTAB,X
LDA ?XT
STA XTAB,X
RTS
;
; Get monster coords for bitmap
;
GETCOORD LDA YTAB,X
TAY
STX ?TEMP
LDA XTAB,X
SEC
SBC #4
TAX
RTS
;
; Plot monster number .x as
; bitmap in (.y.a)
;
PLOTC STA PTR
STY PTR+1
JSR GETCOORD
JSR PLOTMAP
LDX ?TEMP
RTS
;
; Animate 12 monsters 1 cycle
; each.
;
CYCLE
LDX #11
?CYC1 LDA DSTAB,X ;Status 0?
BEQ ?CYC2
BMI ?CYCM ;move if here
AND #$FE
TAY ;get right
ASL A
STA AUDF3
LDA EXPLTAB,Y ;explosion
PHA
LDA EXPLTAB+1,Y
TAY
PLA
JSR PLOTC ;next expl.
INC DSTAB,X
LDA DSTAB,X
CMP #16
BCC ?CYC2
JSR KILLMON
DEC MONLEFT
LDA #0
STA AUDC3
JMP ?CYC2
?CYCM JSR MOVE1 ;move
LDA #<SQUARE
LDY #>SQUARE
JSR PLOTC ;draw
?CYC2 DEX
BPL ?CYC1
LDA NEEDLEY ;Extra man here?
BEQ ?CYCX ;No, go away
AND #7 ;Yes, do next
TAX ;sound
LDA NEEDLES,X
STA AUDF4
LDX #<NEEDLE ;Point to
LDY #>NEEDLE ;bitmap
STX PTR
STY PTR+1
LDX NEEDLEX
INC NEEDLEY ;Move it
LDY NEEDLEY ;Off the
CPY #89 ;screen?
BCC ?NEED1 ;No, draw it
JSR ERASEBM ;Yes, erase
LDA #0 ;And de-flag
STA NEEDLEY ;it.
STA AUDC4
?CYCX RTS ;Exit here!!!
?NEED1 JMP PLOTMAP
;
; Initialize monster .x at x-
; coord in .a
;
INITMON STA XTAB,X
LDA #10
STA YTAB,X
LDA MOTHERDX
LDY SKILL
BEQ ?IMON1
LDA RANDOM
AND #1
BNE ?IMON1
LDA #$FF
?IMON1 STA DXTAB,X
LDA #1
STA DYTAB,X
LDA #$80
STA DSTAB,X ;status here
INC MONHERE
RTS
;
; Kill monster number .x
;
KILLMON
LDA #<SQUARE ;erase it
STA PTR
LDA #>SQUARE
STA PTR+1
JSR GETCOORD
JSR ERASEBM
LDX ?TEMP
LDA #0
STA DSTAB,X ;kill it
DEC MONHERE
?KM1 RTS
;
; Init a new wave of monsters
;
MONSTERS .BYTE 0
MONLEFT .BYTE 0
MONHERE .BYTE 0
INITWAVE LDA #12
STA MONLEFT
LDA #0
STA NEEDLEF
STA MONSTERS
STA MONHERE
LDX #[16*5]-1
?IWV1 STA XTAB,X
DEX
BPL ?IWV1
RTS
;
; Put a monster on at interval
; of $A5 or $85 moves
;
ALIEN DEC ALCOUNT
BNE ?ALX
LDA NEEDLEF
BNE ?AL0
LDA MONSTERS
CMP #12
BEQ ?AL0
LDA RANDOM
AND #7
BNE ?AL0
LDA MOTHERX
CLC
ADC #3
STA NEEDLEX
LDA #5
STA NEEDLEY
STA NEEDLEF
LDA #$A6
STA AUDC4
BNE ?ALS
?AL0 LDA MONHERE
CMP #6
BCS ?ALX
LDX MONSTERS
CPX #12
BCS ?ALX
LDA MOTHERX
JSR INITMON
INC MONSTERS
?ALS LDA #$A5
LDX SPEED
BEQ ?ALP
LDA #$65
?ALP STA ALCOUNT
?ALX RTS
NEEDLES .BYTE 20,40,80,120,200,120,80,40
;
; Player ship move routines
; (also laser handling)
;
.LOCAL
;
; Move player's ship one
; cycle based on joystick.
;
MOVESHIP LDA $027C ;left stick?
BNE ?MSHIP1 ;no, do next
LDA SHIPX ;can he go further?
CMP #8
BEQ ?MSHIP1 ;no, exit
DEC SHIPX ;yes, do it
?MSHIP1 LDA $027D ;check for right
BNE ?MSHIPX
LDA SHIPX
CMP #144
BEQ ?MSHIPX
INC SHIPX
?MSHIPX LDA SHIPX
CLC
ADC #48
STA $D000 ;do the move
RTS
;
; Move player's laser one cycle
; or check for fire if no laser
; is up
;
MISSILES = PLAYER0-$80
MOVELASER LDA LASERY
BEQ ?CFIRE
DEC LASERY
DEC LASERY
DEC LASERY
LDX LASERY
STX AUDF2
LDA #3
STA MISSILES,X
STA MISSILES+1,X
STA MISSILES+2,X
LDA #0
STA MISSILES+6,X
STA MISSILES+7,X
STA MISSILES+8,X
CPX #26
BCS ?LEXIT
JSR CLRLASER
?CFIRE LDA STRIG0
BNE ?LEXIT
LDA SHIPX
CLC
ADC #3
STA LASERX
ADC #48
STA $D004 ;hposm0
LDA #94
STA LASERY
LDA #$C4
STA AUDC2
?LEXIT RTS
;
; Clear out laser.
;
CLRLASER LDX LASERY
LDA #0
STA MISSILES,X
STA MISSILES+1,X
STA MISSILES+2,X
STA MISSILES+3,X
STA MISSILES+4,X
STA MISSILES+5,X
STA LASERY
LDA #0
STA $D203 ;AUDC2
RTS
LASERY .BYTE 0
LASERX .BYTE 0
SPEED .BYTE 0
SKILL .BYTE 0
;
; Routines for title page,
; initialization, and
; game startup.
;
.LOCAL
;
; Set up play screen:
; 1. Clear screen memory.
; 2. Initialize players
; 3. Do display list
; 4. Setup DLI
;
PLAYSCRN LDA #>SCREEN
STA ADDER+1
LDA #<SCREEN
STA ADDER
TAY
LDX #$0F
?PSCN1 STA (ADDER),Y
INY
BNE ?PSCN1
INC ADDER+1
DEX
BNE ?PSCN1
JSR PMINIT
LDA #0
STA 559
JSR VBWAIT
LDA #$FA
STA 709 ;FORCE FIELD
LDA #$A6
STA 710 ;ALIENS
LDA #$3C
STA 708 ;EXPLOSION
LDA #<MAINDL
STA 560
LDA #>MAINDL
STA 561
LDA #3
STA 53277 ;gractl
LDA #<PLAYDLI
STA $0200
LDA #>PLAYDLI
STA $0201
JSR $E465 ;SIOINV
LDA #46
STA 559
RTS
;
; Display list interrupt for
; play screen
;
PLAYDLI PHA
LDA #$86
STA $D40A ;wsync
STA $D01A
LDA #$0A
STA $D016
PLA
RTI
;
; Wait for vertical blank.
;
VBWAIT LDA $14
?VBW1 CMP $14
BEQ ?VBW1
RTS
;
; Lower mother ship (for game
; startup) and init her vars
;
LOWERMOM LDA #0
STA MOTHERDX
LDA #$50
STA AUDF1
LDA #$48
STA AUDC1
?LMOM1 LDY MOTHERDX
JSR PLOTMOM
JSR VBWAIT
JSR VBWAIT
JSR VBWAIT
JSR VBWAIT
JSR VBWAIT
INC MOTHERDX
LDA MOTHERDX
CMP #17
BCC ?LMOM1
LDA #1
STA MOTHERDX
LDA #80
STA MOTHERX
LDA #0
STA AUDC1
RTS
;
; Lower generators to the proper
; height and do fancy force
; field startup (with sound).
;
?FLEVL .BYTE 0
LOWERFORCE
JSR CLRLASER
LDX ROUND
LDA FORCELEV,X
STA FORCEY
LDA #$A8
STA AUDC1
?LFOR1 LDA ?FLEVL
STA AUDF1
SEC
SBC #5
TAY
JSR PLOTGEN
JSR VBWAIT
JSR VBWAIT
JSR VBWAIT
INC ?FLEVL
LDA ?FLEVL
SEC
SBC #11
BMI ?LFOR1
CMP FORCEY
BCC ?LFOR1
BEQ ?LFOR1
LDA #$AA
JSR PLOTFIELD
LDA #$50
STA AUDF1
LDX #0
?LFOR2 LDA FORCETAB,X
STA 709
ORA #$60
STA AUDC1
JSR VBWAIT
JSR VBWAIT
JSR VBWAIT
INX
CPX #9
BCC ?LFOR2
LDA #$64 ;Force field
STA AUDC1 ;Background
LDA #$F0 ;Sound effect
STA AUDF1
RTS
FORCETAB .BYTE $02,$08,$0E,$0E,$0C,$0A,$08,$06,$04
FORCELEV .BYTE 15,30,40,45,50,55,60,65,70,72
;
; Put up and init player ship
;
DOSHIP
LDX #94
JSR PUTSHIP
LDA #76
STA SHIPX
LDA #76+48
STA $D000
JMP CLRLASER
;
; Combine it all into the startup
; sequence.
;
STARTUP LDX #$7F
LDA #0
?S1 STA $80,X
DEX
BPL ?S1
STA NOSHIPS
JSR SHIPSLFT
JSR PLAYSCRN
JSR CLRSCR
JSR LOWERMOM
LDA #0
STA ?FLEVL
STA ROUND
JSR LOWERFORCE
LDA #2
STA NOSHIPS
JSR SHIPSLFT
JSR DOSHIP
JSR INITWAVE
STA $D01E ;hitclr
JMP MLOOP
;
; DLI routine for title page
;
TITLEDLI PHA
TXA
PHA
TYA
PHA
DEC 256
LDY #32
LDX 256
?TDLI STX $D40A ;wsync
STX $D016
INX
DEY
BPL ?TDLI
PLA
TAY
PLA
TAX
PLA
RTI
;
; Display title page and wait
; for START.
;
DOTITLE
LDA #>CHARSET
STA 756
LDA #0
STA 559
STA $D208 ;AUDCTL
STA 53277 ;gractl
JSR VBWAIT
LDA #$FA
STA 709
LDA #$A8
STA 710
LDA #$C8
STA 711
LDA #<TITLEDL
STA 560
LDA #>TITLEDL
STA 561
LDA #<TITLEDLI
STA $0200
LDA #>TITLEDLI
STA $0201
LDA #$C0
STA $D40E ;nmien
JSR PUTSKILL
LDA #42
STA 559
?DTL1