; MONEY HUNGRY
;
; BY DONALD MURPHY
;
; ANALOG COMPUTING
;
;VARIABLES
;
LEVEL = $80     ;LEVEL #
DELAY = $81     ;DELAY INDEX
HERE =  $82
NOX =   $83     ;HORIZ. MOVE FLAG
NOY =   $84     ;VERT. MOVE FLAG
TX  =   $85     ;X HOLD AREA
DM  =   $86     ;MISC. VARIABLE
XM  =   $87     ;HORIZ. FLAG
YM  =   $88     ;VERT. FLAG
DIRC =  $89     ;ENMY CUR DIRECTION
DIRN =  $8C     ;NEXT ENMY DIRECTION
NDOOR = $8F     ;# OF DOORS
TF3 =   $90
TF4 =   $91
POINTL = $B0    ;GENERAL POINTER
POINTH = $B1
TABPTL = $B2    ;TABLE POINTER
TABPTH = $B3
VBPNTL = $B4    ;VBLANK POINTER
VBPNTH = $B5
EDELAY = $B6    ;ENEMY DELAY
ELEVEL = $B7    ;ENEMY LEVEL
XPOSP0 = $B8    ;HORIZ. POS. PLR 0
XPOSP1 = $B9    ;HORIZ. POS. PLR 1
XPOSP2 = $BA    ;HORIZ. POS. PLR 2
XPOSP3 = $BB    ;HORIZ. POS. PLR 3
SCOUNT = $BC    ;SCORE COUNT TO ADD
YPOSP0 = $BD    ;VERT. POS. PLR 0
YPOSP1 = $BE    ;VERT. POS. PLR 1
YPOSP2 = $BF    ;VERT. POS. PLR 2
YPOSP3 = $C0    ;VERT. POS. PLR 3
TEMPX = $C1     ;VERT. POS. PLR 4
DRES =  $C2     ;DIVISION RESULT
LDIV =  $C3     ;LOW DIVIDEND
DIVS =  $C4     ;DIVISOR
XPOSSC = $C5    ;HOR. POS. ON SCRN
YPOSSC = $C6    ;VERT POS. ON SCRN
MUPL =  $C7     ;LO MULTIPLIER
MUCN =  $C8     ;MULTIPLICAND
RESL =  $C9     ;RESULT
RESH =  $CA
STICKC = $CB    ;STICK VALUE
STICKN = $CC    ;NEXT STICK VALUE
NDOTS = $CD     ;#DOTS EATEN
;
;HARDWARE & SHADOW LOCATIONS
;
COLOR0 = $02C4  ;PLAYFIELD COLORS
COLOR1 = $02C5
COLOR2 = $02C6
SDLSTL = $0230  ;DISP LIST POINTER
SDLSTH = $0231
CHBAS = $02F4   ;CHAR BASE ADDR
GRACTL = $D01D  ;GRAPHICS CONTROL
SDMCTL = $022F  ;DMA CONTROL
COLPM0 = $D012  ;P/M COLORS
COLPM1 = $D013
COLPM2 = $D014
COLPM3 = $D015
HPOSP0 = $D000  ;PLAYER HOR. POS.
HPOSP1 = $D001
HPOSP2 = $D002
HPOSP3 = $D003
PMBASE = $D407  ;P/M BASE ADDRESS
VCOUNT = $D40B  ;VERT. LINE COUNTER
WSYNC = $D40A   ;WAIT FOR SYNC
P0PF =  $D004   ;COLLISION REGISTERS
P0PL =  $D00C
P1PF =  $D005
HITCLR = $D01E  ;COLLISION CLEAR
RANDOM = $D20A  ;RANDOM #
NMIST = $D40F   ;NMI STATUS
AUDCTL = $D208  ;AUDIO CONTROL
AUDC1 = $D201   ;AUD. CHANNELS
AUDC2 = $D203
AUDF1 = $D200   ;AUD. FREQUENCIES
AUDF2 = $D202
CONSOL = $D01F  ;CONSOLE KEYS
SKCTL = $0232   ;SERIAL PORT CTRL
GPRIOR = $026F  ;P/M PRIORITY
STICK0 = $0278  ;STICK 0
STRIG0 = $0284  ;BUTTON 0
;
;TABLES AND RAM ASSIGNMENTS
;
CTAB0 = $1800   ;PL.0 COLORS
CTAB1 = $1900   ;PL.1 COLORS
CTAB2 = $1A00   ;PL.2 COLORS
CTAB3 = $1B00   ;PL.3 COLORS
CHSET = $3800   ;CHARACTER SET
SCRAM = $3A00   ;SCREEN ADDRESS
PMRAM = $1C00   ;P/M ADDRESS
;
;PROGRAM START
;
    *=  $209E
;
;TITLE SCREEN DISPLAY LIST
;
TSCRD .BYTE 112,112,112,112,112
    .BYTE 112,112,$47
    .WORD TSCRW
    .BYTE 112,6,112,7,112,112,112
    .BYTE 112,6,$41
    .WORD TSCRD
;
;TITLE SCREEN DATA
;
TSCRW .BYTE 0,0,0,0,45,47,46,37
    .BYTE 57,0,40,53,46,39,50,57
    .BYTE 0,0,0,0,0,0,0,0,0,0,0,0,0
    .BYTE 226,249,0,0,0,0,0,0,0,0,0
    .BYTE 0,0,0,100,111,110,97
    .BYTE 108,100,0,0,109,117,114
    .BYTE 112,104,121,0,0,0,240,242
    .BYTE 229,243,243,0,243,244,225
    .BYTE 242,244,0,244,239,0,226
    .BYTE 229,231,233,238
;
;GAME BOARD DISPLAY LIST
;
DLIST .BYTE 112,112,112,$45
    .WORD SCRAM
    .BYTE 5,5,5,5,5,5,5
    .BYTE 5,5,5,7,65
    .WORD DLIST
;
;PLAYER COLORS & BIT MAPS
;
ENBMAP .BYTE 54,20,127,54
    .BYTE 42,127,28,62,0
ENCMAP .BYTE $FA,$8A,$8A,$BA
    .BYTE $E6,$E6,$FF,$BA,$FF
PLBMAP .BYTE 119,28,8,20,62
    .BYTE 28,28,62,0
PLCMAP .BYTE $38,$88,$88,$EA
    .BYTE $EA,$38,$EA,$EA,$38
GAME .BYTE $A7,$A1,$AD,$A5
OVER .BYTE $AF,$B6,$A5,$B2
;
;GAME EXECUTION STARTS HERE!
;
INIT LDX #0
INILP LDA CHDAT,X ;SET UP
    STA CHSET,X ;CHAR SET
    LDA CHDAT+256,X
    STA CHSET+256,X
    LDA SCDAT,X ;AND SCREEN
    STA SCRAM,X
    LDA SCDAT+256,X
    STA SCRAM+256,X
    DEX
    BNE INILP
    LDA # >TSCRD ;SHOW...
    STA SDLSTH  ;TITLE SCREEN
    LDA # <TSCRD
    STA SDLSTL
    LDA #$22
    STA SDMCTL
PROG LDA CONSOL ;GET CONSOLE
    CMP #6      ;START PRESSED?
    BEQ GO      ;YES!
    LDA STRIG0  ;TRIGGER PRESSED?
    BNE PROG    ;NO!
GO  LDA <DLIST  ;SHOW...
    STA SDLSTL  ;GAME SCREEN
    LDA >DLIST
    STA SDLSTH
    LDA >CHSET  ;POINT TO
    STA CHBAS   ;CHAR SET
    LDA #$88    ;SET COLORS
    STA COLOR0
    LDA #$FC
    STA COLOR1
    LDA #$36
    STA COLOR2
    LDA #0      ;SET...
    STA GPRIOR  ;PRIORITY
    STA AUDCTL  ;AND AUDIO
    LDA #3      ;RESET SOUNDS
    STA SKCTL
    JSR SETSC   ;SETUP SCREEN
    JSR SETPM   ;SETUP P/M
    JSR SETPL   ;SET YOU
    JSR SETEM   ;SET ENEMIES
    STA HITCLR  ;CLEAR COLLISIONS
    JSR INT     ;MISC. INIT.
    JSR SETVB   ;START VBLANK
    JSR PRIZE   ;INIT MONEY BAG
    LDX #0      ;ZERO X REG
;
;MAINLINE COLOR LOOP
;
COLOR LDA P0PL  ;HIT ANYTHING?
    BEQ CONT    ;NO, CONTINUE
    JMP DEATH   ;YOU'RE DEAD!
CONT STA WSYNC  ;WAIT FOR SYNC
    LDY VCOUNT  ;GET VERT LINE#
    LDA CTAB0,Y ;GET COLOR FOR
    STA COLPM0  ;PLAYER 0
    LDA CTAB1,Y ;GET COLOR FOR
    STA COLPM1  ;PLAYER 1
    LDA CTAB2,Y ;GET COLOR FOR
    STA COLPM2  ;PLAYER 2
    LDA CTAB3,Y ;GET COLOR FOR
    STA COLPM3  ;PLAYER 3
    LDA NDOTS   ;# OF DOTS...
    CMP #107    ;=107?
    BCC COLOR   ;NO, GET NEXT COLOR
    JMP NEXTL   ;NEW LEVEL!
;
;DEFERRED VBLANK
;
DVBL DEC EDELAY ;TIME FOR EN. MOVE?
    BEQ EDO     ;YES!
    JMP END0     ;NO, EXIT
EDO LDA ELEVEL  ;RESET MOVE TIMER
    STA EDELAY
    LDA #PMRAM/256+2 ;POINT TO
    STA POINTH  ;PLAYERS
    LDA #$80
    STA POINTL
    LDA #CTAB1/256 ;GET COLOR...
    STA TABPTH  ;TABLE OFFSET
    LDA #0
    STA TABPTL
    TAX         ;ZERO X
MAIN LDA P1PF,X ;HIT ANYTHING?
    AND #4      ;GET COLL. BITS
    BEQ NHDR    ;NO COLLISIONS
    STA HITCLR  ;RESET COLLISIONS
    LDA DIRN,X  ;NEXT DIRECTION
    CMP DIRC,X  ;= CURRENT DIR?
    BNE EOR1    ;NO, CHANGE IT.
    EOR #1      ;REVERSE IT,
    STA DIRN,X  ;STORE IT.
EOR1 LDA DIRC,X ;GET CURRENT
    EOR #1      ;REVERSE IT,
    STA DIRC,X  ;AND STORE.
NHDR STX TEMPX  ;SAVE X
    LDA XPOSP1,X ;GET PLAYER X'S
    CLC         ;HORIZ. POS,
    ADC #1      ;ADD 1,
    LDY YPOSP1,X ;GET VERT POS,
    INY         ;ADD 1
    JSR PMOVE   ;MOVE PLAYER
    LDX TEMPX   ;GET X AGAIN
    LDA DIRN,X  ;GET NEXT DIRECTION
    AND #2      ;GET 1ST 2 BITS
    BEQ TXM     ;TRY HORIZ. MOVE
    LDA YM      ;OK TO MOVE VERT?
    BEQ CCHD    ;YES, CHANGE DIR
    JMP KCD     ;NO, KEEP CURRENT
TXM LDA XM      ;HORIZ MOVE OK?
    BNE KCD     ;NO, KEEP CURRENT
CCHD LDA DIRN,X ;CHANGE DIRECTION
    STA DIRC,X  ;STORE NEXT DIR
    LDA RANDOM  ;GET RANDOM #
    AND #3      ;MASK TO 0-3
    STA DIRN,X  ;SAVE FOR NEXT
KCD LDA DIRC,X  ;GET CURRENT DIR
    BNE TA1     ;NOT RIGHT
    JMP MPXR    ;MOVE RIGHT!
TA1 CMP #1      ;IS IT LEFT?
    BNE TA2     ;NO!
    JMP MPXL    ;MOVE LEFT!
TA2 CMP #2      ;IS IT UP?
    BNE TA3     ;NO!
    JMP MPXU    ;MOVE UP!
TA3 JMP MPXD    ;MOVE DOWN!
;
;SET UP SCREEN
;
SETSC LDA #0    ;ERASE MONEY BAG
    STA SCRAM+219
    STA SCRAM+220
    LDA <SCRAM  ;POINT...
    STA POINTL  ;TO SCREEN
    LDA >SCRAM
    STA POINTH
    LDY #6      ;SCRN BORDER OFFSET
L1  LDA (POINTL),Y ;GET SCRN BYTE
    BEQ NFL     ;EMPTY-PLOT DOT!
    CMP #30     ;IS IT DOT?
    BEQ NFL     ;YES, PLOT AGAIN!
    CMP #31     ;WALL?
    BNE PL1     ;YES, DON'T PLOT
    DEY         ;PREVIOUS POS.
    LDA #0      ;ZERO IT!
    STA (POINTL),Y
    INY         ;BACK TO THIS POS.
NFL LDA #17     ;PLOT A DOT.
    STA (POINTL),Y
PL1 INY         ;NEXT POSITION
    INY
    CPY #36     ;END OF LINE?
    BCC L1      ;NO!
    LDA POINTL  ;INCREMENT...
    CLC         ;POINTER...
    ADC #40     ;TO NEXT LINE
    STA POINTL
    LDA POINTH
    ADC #0
    STA POINTH
    LDY #6      ;LAST LINE?
    CMP >SCRAM+1
    BCC L1      ;NO!
    LDA POINTL  ;LAST LINE?
    CMP #144
    BNE L1      ;NO!
    LDA #0      ;RESET...
    STA NDOTS   ;# OF DOTS
    STA SCOUNT  ;AND SCORE COUNT
    LDA #5      ;RESET # DOORS
    STA NDOOR
    RTS         ;ALL DONE!
;
;INIT PLAYER-MISSILE GRAPHICS
;
SETPM LDA #PMRAM/256+2 ;POINT...
    STA POINTH  ;TO...
    LDA #0      ;PLAYER MEMORY
    STA POINTL
    TAY         ;ZERO Y REG.
L3  STA (POINTL),Y ;ZERO P/M AREA
    INY
    BNE L3
    INC POINTH
    LDX POINTH  ;DONE CLEARING?
    CPX #PMRAM/256+4
    BNE L3      ;NO!
    LDA #CTAB0/256 ;POINT...
    STA POINTH  ;TO...
    LDA #0      ;COLOR TABLES
    STA POINTL
    TAY         ;ZERO Y REG.
Q1  STA (POINTL),Y ;ZERO COLOR TABLES
    INY
    BNE Q1
    INC POINTH
    LDX POINTH  ;DONE CLEARING?
    CPX #CTAB3/256+1
    BNE Q1      ;NO!
    LDA #46     ;TURN ON P/M
    STA SDMCTL
    LDA #3
    STA GRACTL
    LDA >PMRAM  ;POINT TO...
    STA PMBASE  ;P/M AREA
    RTS         ;ALL DONE!
;
;RUN VBLANK ROUTINES
;
SETVB LDA #6    ;SET IMMEDIATE!
    LDX >VBLANK
    LDY <VBLANK
    JSR $E45C
    LDA #64     ;TURN ON
    STA NMIST
    LDA #7      ;SET DEFERRED!
    LDX >DVBL
    LDY <DVBL
    JMP $E45C   ;ALL DONE!
;
;DRAW ENEMIES ON SCREEN
;
SETEM LDA #$80  ;POINT TO P/M
    STA POINTL
    LDA >PMRAM+2
    STA POINTH
    LDA #0      ;POINT TO COLORS
    STA TABPTL
    LDA >CTAB1
    STA TABPTH
L4  LDY #23     ;P/M VERT OFFSET
    LDX #8      ;P/M HEIGHT
L5  LDA ENBMAP,X ;DRAW ONE!
    STA (POINTL),Y
    LDA ENCMAP,X
    STA (TABPTL),Y
    INY
    DEX
    BPL L5
    INC TABPTH  ;NEXT COLOR TABLE
    LDA POINTL  ;NEXT PLAYER
    CLC
    ADC #$80
    STA POINTL
    LDA POINTH
    ADC #0
    STA POINTH
    CMP >PMRAM+4 ;LAST PLAYER?
    BCC L4      ;NO!
    LDA #$43    ;PL 1 HORIZONTAL
    STA XPOSP1
    STA HPOSP1
    LDA #$84    ;PL 2 HORIZONTAL
    STA XPOSP2
    STA HPOSP2
    LDA #$B3    ;PL 3 HORIZONTAL
    STA XPOSP3
    STA HPOSP3
    LDA #23     ;ALL VERTICAL
    STA YPOSP1
    STA YPOSP2
    STA YPOSP3
    LDA #3      ;P1&3 GOING DOWN
    STA DIRC
    STA DIRC+2
    LDA #1      ;P2 GOING LEFT
    STA DIRC+1
    RTS         ;ALL DONE!
;
;SET UP YOUR PLAYER
;
SETPL LDX #8    ;8 BYTES TALL
    LDY #55     ;GET VERT OFFSET
L6  LDA PLBMAP,X ;DRAW HIM!
    STA PMRAM+512,Y
    LDA PLCMAP,X
    STA CTAB0,Y
    INY
    DEX
    BPL L6
    LDA #124    ;SET HORIZ POS
    STA XPOSP0
    STA HPOSP0
    LDA #55     ;AND VERT POS
    STA YPOSP0
    LDA #11     ;GOING LEFT!
    STA STICKC
    STA STICKN
    RTS         ;BYE!
;
;IMMEDIATE VBLANK
;
VBLANK LDA #0   ;TURN OFF...
    STA AUDC1   ;SOUND 1
    STA AUDC2   ;SOUND 2
    LDX XPOSP0  ;GET PLAYER X
    INX         ;OFFSET FOR SCRN
    LDY YPOSP0  ;GET PLAYER Y
    INY         ;OFFSET IT TOO
    JSR PMTGR   ;CONVERT TO SCRN LOC
    JSR XYTOME  ;THEN TO ADDRESS
    DEC DELAY   ;OK TO MOVE?
    BEQ DO      ;YUP!
    JMP ENDVB   ;NO, EXIT.
DO  LDA LEVEL   ;RESET TIMER
    STA DELAY
    LDA STICKN  ;GET NEXT DIRECTION
    AND #3      ;MASK IT,
    CMP #3      ;HORIZ MOVEMENT?
    BEQ TNM     ;YES!
    LDA NOY     ;CHECK IF VERT CLEAR
    BEQ CHD     ;IT'S CLEAR!
    JMP CD      ;KEEP CURRENT DIR
TNM LDA NOX     ;HORIZ CLEAR?
    BNE CD      ;NO! KEEP CURRENT
CHD LDA STICKN  ;GET NEXT MOVE
    STA STICKC  ;SAVE IN CURRENT
CD  LDA STICK0  ;GET STICK
    CMP #15     ;MOVED?
    BEQ NC      ;NO!
    STA STICKN  ;SAVE NEW MOVE
NC  LDA STICKC  ;GET CURRENT
    CMP #15     ;MOVED?
    BNE N15     ;YES!
    JMP ENDVB   ;NO, EXIT.
N15 CMP #10     ;UP?
    BEQ MU      ;YES!
    CMP #6      ;UP?
    BEQ MU      ;YES!
    CMP #14     ;UP?
    BNE VBP1    ;NO!
MU  LDX #$0A    ;10 BYTES TO MOVE
    LDY YPOSP0  ;GET VERT OFFSET
    CPY #24     ;AT TOP?
    BCS VBL1    ;NO, MOVE IT!
    JMP ENDVB   ;BYE!
VBL1 LDA PMRAM+512,Y ;MOVE PLAYER
    STA PMRAM+511,Y
    LDA CTAB0,Y
    STA CTAB0-1,Y
    INY
    DEX
    BNE VBL1
    DEC YPOSP0  ;DEC VERT POS.
MUE JMP ENDVB   ;BYE!
VBP1 CMP #9     ;DOWN?
    BEQ MD      ;YES!
    CMP #5      ;DOWN?
    BEQ MD      ;YES!
    CMP #13     ;DOWN?
    BNE VBP2    ;NO!
MD  LDA YPOSP0  ;AT BOTTOM?
    CMP #87
    BCC OKMD    ;NO, MOVE IT!
    JMP ENDVB   ;;BYE!
OKMD ADC #9     ;GET LAST PLAYER BYTE
    TAY         ;PUT IN Y
    LDX #$0A    ;10 BYTES TO MOVE
VBL2 LDA PMRAM+511,Y ;MOVE PLAYER
    STA PMRAM+512,Y
    LDA CTAB0-1,Y
    STA CTAB0,Y
    DEY
    DEX
    BNE VBL2
    INC YPOSP0  ;INC VERT POS.
MDE JMP ENDVB   ;BYE!
VBP2 CMP #11    ;LEFT?
    BNE VBP3    ;NO!
    LDX XPOSP0  ;TOO FAR LEFT?
    CPX #68
    BCS OKML    ;NO!
    JMP ENDVB   ;BYE!
OKML DEX        ;DEC HORIZ POS
    STX XPOSP0
    STX HPOSP0
MLE JMP ENDVB   ;BYE!
VBP3 LDX XPOSP0 ;TOO FAR RIGHT?
    CPX #179
    BCC OKMR    ;NO!
    JMP ENDVB   ;BYE!
OKMR INX        ;INC HORIZ POS
    STX XPOSP0
    STX HPOSP0
ENDVB JMP $E45F ;LEAVE VBLANK!
;
;P/M TO SCREEN COORDS SUBROUTINE
;
PMTGR STX XPOSSC ;SAVE HORIZ
    STY YPOSSC  ;SAVE VERT
    TYA         ;GET VERT IN A
    SEC         ;SUB SCREEN OFFSET
    SBC #16
    STA LDIV    ;SAVE IN DIVIDER
    LDA #8      ;DIV. BY 8
    STA DIVS
    LDA #0      ;ZERO RESULT
    STA DRES
    JSR DIVIDE  ;DIVIDE IT!
    STA NOX     ;STORE REMAINDER
    LDA DRES    ;GET RESULT
    STA YPOSSC  ;SAVE SCREEN Y
    AND #1      ;EVEN OR ODD?
    BNE OD1     ;ODD!
    LDA #1      ;PROHIBIT ANY
    STA NOX     ;HORIZONTAL MOVE
OD1 LDA XPOSSC  ;GET HORIZ.
    SEC         ;SUB SCREEN OFFSET
    SBC #48
    STA LDIV    ;PUT IN DIVIDER
    LDA #4      ;DIVIDE BY 4
    STA DIVS
    LDA #0      ;ZERO RESULT
    STA DRES
    JSR DIVIDE  ;DIVIDE IT!
    STA NOY     ;SAVE REMAINDER
    LDA DRES    ;GET RESULT
    STA XPOSSC  ;SAVE SCREEN X
    AND #3      ;IS VERT MOVE OK?
    EOR #1
    BEQ OD2     ;YES!
    LDA #1      ;PROHIBIT ALL
    STA NOY     ;VERTICAL MOVES
OD2 LDA DRES    ;GET RESULT
    STA XPOSSC  ;SAVE SCREEN X
    RTS         ;ALL DONE!
;
;X&Y COORDS TO MEMORY ADDRESS
;
XYTOME LDA #0   ;ZERO...
    STA VBPNTL  ;VBLANK POINTER
    STA RESH    ;AND RESULT
    LDA STICKC  ;GET CURRENT DIR.
    AND #1      ;LEFT?
    BNE NI      ;NO!
    LDA STICKN  ;GET NEXT DIR
    CMP #11     ;LEFT?
    BNE INCY    ;NO!
    DEC YPOSSC  ;CANCEL NEXT INC
INCY INC YPOSSC ;INC VERT POS
NI  LDA YPOSSC  ;GET VERT
    STA MUPL    ;SAVE MULTIPLIER
    LDA #40     ;TIMES 40
    STA MUCN
    JSR MULT    ;MULTIPLY IT!
    INC XPOSSC  ;INC HORIZ POS
    LDA XPOSSC  ;GET IT,
    CLC         ;ADD RESULT
    ADC RESL
    STA VBPNTL  ;SAVE IN POINTER
    LDA RESH
    ADC #SCRAM/256 ;ADD SCRN BASE
    STA VBPNTH
    LDY #0      ;ZERO Y
    LDA (VBPNTL),Y ;GET BYTE
    CMP #30     ;IS IT DOOR?
    BNE DCHD    ;NO!
    LDA #38     ;MAKE DOOR SOUND
    STA AUDC1
    LDA #20
    STA AUDF1
    LDA #0
    TAY
    STA (VBPNTL),Y ;ERASE DOOR
    INC NDOOR   ;1 MORE DOOR
DCHD CMP #31    ;IS IT DOOR?
    BNE CVDA    ;NO!
    LDA #38     ;MAKE DOOR SOUND
    STA AUDC1
    LDA #20
    STA AUDF1
    LDA #0
    TAY
    STA (VBPNTL),Y ;ERASE DOOR
    DEC VBPNTL  ;(2 BYTES)
    STA (VBPNTL),Y
    INC VBPNTL
    INC NDOOR   ;1 MORE DOOR
CVDA CMP #17    ;IS IT A DOT?
    BEQ CC      ;YES!
    CMP #29     ;MONEY BAG?
    BNE R       ;NO!
    LDA #166    ;MAKE SOUND
    STA AUDC1
    LDA #220
    STA AUDF1
    LDX #100    ;ADD 100 TO SCORE
    STX SCOUNT
    DEC VBPNTL  ;ERASE MONEY BAG
    TYA
    STA (VBPNTL),Y
    INC VBPNTL
    STA (VBPNTL),Y
    RTS         ;AND EXIT!
CC  TYA         ;ERASE DOT
    STA (VBPNTL),Y
    INC NDOTS   ;1 MORE DOT TAKEN
    LDX #1      ;ADD 1 POINT
    STX SCOUNT
    LDA #95     ;MAKE SOUND
    STA AUDC1
    LDA #185
    STA AUDF1
R   RTS         ;AND EXIT!
;
;GENERAL-PURPOSE DIVIDE ROUTINE
;
DIVIDE LDY #8   ;GET # OF BITS
    SEC         ;SUBTRACT DIVISOR
    SBC DIVS
DILO PHP        ;SAVE PROC. STATUS
    ROL DRES    ;ROTATE RESULT
    ASL LDIV    ;SHIFT DIVIDER
    ROL A       ;ROTATE DIVIDER
    PLP         ;GET STATUS BACK
    BCC ADD     ;BRANCH IF CLEAR
    SBC DIVS    ;SUBTRACT DIVISOR
    JMP NEXT    ;CONTINUE
ADD ADC DIVS    ;ADD DIVISOR
NEXT DEY        ;LAST BIT?
    BNE DILO    ;NO!
    BCS LAST    ;BRANCH IF LAST
    ADC DIVS    ;ADD DIVISOR
    CLC         ;CLEAR CARRY
LAST ROL DRES   ;ROTATE RESULT
    RTS         ;AND EXIT.
;
;MULTIPLY SUBROUTINE
;
MULT LDA #0     ;ZERO RESULT
    STA RESL
    LDX #8      ;8 BITS
MLOP LSR MUPL   ;SHIFT MULTIPLIER
    BCC NOADD   ;HI BIT EMPTY
    CLC         ;ADD MULTIPLICAND
    ADC MUCN
NOADD ROR A     ;ROTATE RESULT
    ROR RESL    ;AND LOW RESULT
    DEX         ;1 MORE BIT
    BNE MLOP    ;MORE TO COME!
    STA RESH    ;SAVE RESULT HI
    RTS         ;AND EXIT
;
;SCOREKEEPING SUBROUTINE
;
SCORE LDY #5    ;6TH SCORE DIGIT
    CPX #1      ;ANY INCREASE?
    BCS GET     ;YES!
    RTS         ;NO, RETURN
GET LDA SCRAM+447,Y ;GET SCORE
    CMP #27     ;>=9?
    BCC NOB     ;NO
    LDA #18     ;WRAP TO ZERO
    STA SCRAM+447,Y
    DEY         ;NEXT CHARACTER
    BPL GET
    RTS         ;ALL DONE!
NOB CLC         ;INCREMENT THE
    ADC #1      ;SCORE
    STA SCRAM+447,Y
    DEX         ;NEXT ADD
    BNE SCORE   ;GO ADD IT!
    RTS         ;ALL DONE!
;
;PLAYER MOVEMENT
;
PMOVE STA YM    ;SAVE ACCUM
    TYA         ;MOVE VERT TO A
    SEC         ;SCREEN OFFSET
    SBC #16
    STA LDIV    ;PUT IN DIVIDER
    LDA #8      ;DIV BY 8
    STA DIVS
    LDA #0      ;CLEAR RESULT
    STA DRES
    JSR DIVIDE  ;DIVIDE IT!
    STA XM      ;SAVE REMAINDER
    LDA DRES    ;GET RESULT
    AND #1      ;ODD?
    BNE OD1M    ;YES!
    LDA #1      ;DON'T PERMIT
    STA XM      ;HORIZ. MOVE
OD1M LDA YM     ;GET VERT
    SEC         ;SUB SCREEN OFFSET
    SBC #48
    STA LDIV    ;STORE IN DIVIDER
    LDA #4      ;DIV BY 4
    STA DIVS
    LDA #0      ;CLEAR RESULT
    STA DRES
    JSR DIVIDE  ;DIVIDE IT!
    STA YM      ;SAVE REMAINDER
    LDA DRES    ;GET RESULT
    AND #3      ;VERT MOVE OK?
    EOR #1
    BEQ OD2M    ;YES!
    LDA #1      ;DON'T ALLOW
    STA YM      ;VERT MOVEMENT
OD2M RTS        ;EXIT!
MPXR LDY XPOSP1,X ;CAN PLAYER
    CPY #179    ;MOVE RIGHT?
    BCC CMR     ;YES!
    JMP END0     ;NO!
CMR INY         ;INCREMENT HORIZ
    TYA         ;PUT IN ACCUM
    STA XPOSP1,X ;SET THE POS
    STA HPOSP1,X
    JMP END0     ;ALL DONE!
MPXL LDY XPOSP1,X ;CAN PLAYER
    CPY #68     ;MOVE LEFT?
    BCS CML     ;YES!
    JMP END0     ;NO!
CML DEY         ;DEC HORIZ
    TYA         ;PUT IN ACCUM
    STA XPOSP1,X ;CHANGE POS
    STA HPOSP1,X
    JMP END0     ;ALL DONE
MPXU LDY YPOSP1,X ;GET VERT
    LDX #$0A    ;10 BYTES TO MOVE
    CPY #24     ;AT TOP?
    BCS CMU     ;NO, CAN MOVE
    JMP END0     ;CAN'T GO UP!
CMU LDA (POINTL),Y ;MOVE UP!
    DEY
    STA (POINTL),Y
    INY
    LDA (TABPTL),Y ;MOVE COLORS
    DEY
    STA (TABPTL),Y
    INY
    INY
    DEX
    BNE CMU
    LDX TEMPX   ;RESTORE X
    DEC YPOSP1,X ;DEC VERT POS
    JMP END0     ;ALL DONE
MPXD LDX TEMPX  ;GET PLAYER #
    LDA YPOSP1,X ;CAN HE...
    CMP #87     ;GO DOWN?
    BCC CMD     ;YES!
    JMP END0     ;NO!
CMD ADC #9      ;GET OFFSET...
    TAY         ;TO PLAYER END
    LDX #$0A    ;10 BYTES
L   DEY
    LDA (POINTL),Y ;MOVE HIM!
    INY
    STA (POINTL),Y
    DEY
    LDA (TABPTL),Y ;MOVE COLOR
    INY
    STA (TABPTL),Y
    DEY
    DEX
    BNE L
    LDX TEMPX   ;RESTORE X
    INC YPOSP1,X ;INC VERT POS
    JMP END0     ;ALL DONE
;
;VBLANK FINISH
;
END0 LDA POINTL  ;ADD 128 TO
    CLC         ;P/M POINTER
    ADC #$80    ;TO INDICATE
    STA POINTL  ;NEXT PLAYER
    LDA POINTH
    ADC #0
    STA POINTH
    INC TABPTH
    LDX TEMPX   ;GET PLAYER #
    INX         ;INCREMENT IT
    CPX #3      ;ALL DONE?
    BCS ENDDVB  ;YES!
    JMP MAIN    ;NO, LOOP BACK!
ENDDVB LDX SCOUNT ;GET SCORE ADD
    LDA #0      ;ZERO IT
    STA SCOUNT
    JSR SCORE   ;ADD TO SCORE
    LDA STRIG0  ;BUTTON PRESSED?
    BNE PQW     ;NO!
    JSR DOOR    ;PLACE A DOOR
PQW JMP $E462   ;VBLANK DONE!
;
;INITIALIZATION SEQUENCE
;
INT LDA #3      ;SET UP...
    STA LEVEL   ;INITIAL SPEEDS
    STA ELEVEL
    STA DELAY
    STA EDELAY
    LDY #19     ;CLEAR SCORE LINE
    LDA #0
CG  STA SCRAM+440,Y
    DEY
    BNE CG
    LDA #$57    ;RESET # MEN
    STA SCRAM+442
    LDY #0      ;ZERO SCORE
    LDA #18
L2  STA SCRAM+447,Y
    INY
    CPY #6
    BNE L2
    RTS         ;ALL DONE!
;
;CHANGE LEVELS
;
NEXTL LDA ELEVEL ;GET ENEMY SPEED
    CMP LEVEL   ;SAME AS PLAYER?
    BEQ NDS     ;YES!
    DEC LEVEL   ;SPEED UP PLAYER
    BNE NOC     ;BUT DON'T ALLOW
    LDA #1      ;LEVEL < 1
    STA LEVEL
NDS DEC ELEVEL  ;SPEED UP ENEMY
    BNE NOC     ;BUT DON'T ALLOW
    LDA #1      ;ELEVEL < 1
    STA ELEVEL
NOC JSR CLRVB   ;CLEAR VBLANK
    JSR SOUND2  ;MAKE A SOUND
    JSR SETSC   ;SET UP SCREEN
    JSR SETPM   ;SET UP P/M
    JSR SETEM   ;SET ENEMIES
    JSR SETPL   ;SET UP PLAYER
    JSR SETVB   ;SET VBLANK
    JSR PRIZE   ;SET UP MONEYBAG
    JMP COLOR   ;DISPLAY COLORS
;
;CLEAR VBLANK VECTORS
;
CLRVB LDA #6    ;IMMEDIATE OFF
    LDX #$E4
    LDY #$5F
    JSR $E45C
    LDA #7      ;DEFERRED OFF
    LDX #$E4
    LDY #$62
    JMP $E45C   ;AND EXIT
;
;MONEY BAG HANDLER
;
PRIZE LDA >MONEY ;SET UP...
    STA $0227   ;TIMER 1 VECTOR...
    LDA <MONEY  ;TO POINT TO...
    STA $0226   ;BAG PRINTER
SETT1 LDA #1    ;SET UP TIMER!
    LDY #0
    LDX #4
    JMP $E45C   ;ALL DONE!
;
;MONEY BAG DISPLAY ROUTINE
;
MONEY LDA #28   ;PUT BAG CHAR 1
    STA SCRAM+219 ;ON SCREEN
    LDA #29     ;PUT BAG CHAR 2
    STA SCRAM+220 ;ON SCREEN
    LDA >MGONE  ;REPOINT TIMER
    STA $0227   ;TO BAG ERASE
    LDA <MGONE  ;ROUTINE
    STA $0226
    JMP SETT1   ;GO SET IT
MGONE LDA #0    ;ERASE BAG
    STA SCRAM+219
    STA SCRAM+220
    RTS         ;AND EXIT
DEATH JSR CLRVB ;TURN OFF VBLANK
    JSR SOUND1  ;DO DEATH SOUND
    LDX SCRAM+442 ;1 LESS LIFE
    DEX
    CPX #$52    ;MORE LIVES?
    BCS STILL   ;YES!
    JMP GOVER   ;GAME OVER!
STILL STX SCRAM+442 ;ZERO LIVES
    JSR SETPM   ;SET UP P/M
    JSR SETPL   ;AND PLAYER
    JSR SETEM   ;AND ENEMIES
    JSR SETVB   ;AND VBLANK
    STA HITCLR  ;CLEAR COLLISIONS
    JMP COLOR   ;AND RESTART!
;
;GAME OVER ROUTINE
;
GOVER LDX #0    ;SHOW MESSAGE:
PR1 LDA GAME,X  ;'GAME'
    STA SCRAM+442,X
    INX
    CPX #4
    BNE PR1
    LDX #0
PR2 LDA OVER,X  ;'OVER'
    STA SCRAM+454,X
    INX
    CPX #4
    BNE PR2
    JMP PROG    ;AND RESTART!
;
;OPEN DOOR
;
DOOR DEC NDOOR  ;1 LESS DOOR
    BNE RED     ;DOORS LEFT
    INC NDOOR   ;NO DOORS!
    RTS         ;EXIT
RED LDA NOY     ;VERTIVAL DOOR?
    BEQ VD      ;YES!
    LDA XPOSSC  ;OK FOR HOR. DOOR?
    AND #3
    BNE ENDD    ;NO!
    LDA #$C0    ;MAKE DOOR SOUND
    STA AUDF2
    LDA #$A3
    STA AUDC2
    LDY #0      ;DRAW DOOR
    LDA #30
    STA (VBPNTL),Y
    RTS         ;AND EXIT
VD  LDA YPOSSC  ;VERT DOOR OK?
    AND #1
    BNE ENDD    ;NO!
    LDA #$C0    ;MAKE DOOR SOUND
    STA AUDF2
    LDA #$A3
    STA AUDC2
    DEC VBPNTL  ;BACK 1 CHAR
    LDY #1      ;DRAW DOOR
    LDA #31
    STA (VBPNTL),Y
    DEY
    STA (VBPNTL),Y
    RTS         ;AND EXIT
ENDD INC NDOOR  ;NO DOOR DISPLAYED,
    RTS         ;RESET & RETURN
;
;SOUND SUBROUTINES
;
SOUND1 LDA #168 ;INIT SOUND
    STA AUDC2
    LDA #100    ;INIT FREQ
  STA TF3
  LDX #$FF    ;LOW DELAY COUNT
  LDY #20     ;HI DELAY COUNT
SL1 LDA TF3   ;GET FREQ
  STA AUDF2   ;STORE IT
  DEX         ;DELAY 1
  BNE SL1     ;LOOP IF NOT READY
  DEY         ;DELAY 2
  BNE SL1     ;LOOP AGAIN
  INC TF3     ;INC FREQUENCY
  INC TF3
  LDY #20     ;RESET HI DELAY
  LDA TF3     ;GET FREQ
  CMP #$A0    ;LAST FREQ?
  BNE SL1     ;NO!
  LDA #136    ;END OF SOUND
  STA AUDC2
  LDA #50
  STA AUDF2
  LDX #255    ;LO DELAY COUNT
  LDY #255    ;HI DELAY COUNT
SL2 DEX       ;DELAY LOOP
  BNE SL2
  DEY
  BNE SL2
  LDA #0      ;SOUND OFF
  STA AUDF2
  STA AUDC2
  RTS         ;BYE!
SOUND2 LDA #168 ;INITIAL SOUND
  STA AUDC1
  LDA #$40    ;INITIAL FREQ
  STA TF4
  LDX #$FF    ;LO DELAY COUNT
  LDY #20
SL3 LDA TF4   ;GET FREQ
  STA AUDF1   ;STORE IT
  DEX         ;DELAY 1
  BNE SL3
  DEY         ;DELAY 2
  BNE SL3
  DEC TF4     ;NEXT FREQ
  DEC TF4
  LDY #20     ;RESET DELAY
  LDA TF4     ;LAST FREQ?
  BNE SL3     ;NO!
  LDA #0      ;TURN OFF SOUND
  STA AUDF1
  STA AUDC1
  RTS         ;AND EXIT
;
;CHARACTER SET DATA
;
CHDAT
  .BYTE 0,0,0,0,0,0,0,0,85,85
  .BYTE 85,170,85,85,85,85,149,149,149,170
  .BYTE 85,85,85,85,85,85,85,170,149,149
  .BYTE 149,149,149,149,149,149,149,149,149,149
  .BYTE 21,21,21,21,21,21,21,21,149,149
  .BYTE 149,170,149,149,149,149,86,86,86,170
  .BYTE 86,86,86,86,85,85,85,170,86,86
  .BYTE 86,86,86,86,86,170,85,85,85,85
  .BYTE 84,84,84,84,84,84,84,84,86,86
  .BYTE 86,86,86,86,86,86,85,85,85,85
  .BYTE 85,85,85,85,149,149,149,149,85,85
  .BYTE 85,85,86,86,86,86,85,85,85,85
  .BYTE 85,85,85,149,149,149,149,149,85,85
  .BYTE 85,86,86,86,86,86,0,0,0,128
  .BYTE 0,0,0,0,0,60,102,110,118,102
  .BYTE 60,0,0,24,56,24,24,24,126,0
  .BYTE 0,60,102,12,24,48,126,0,0,126
  .BYTE 12,24,12,102,60,0,0,12,28,60
  .BYTE 108,126,12,0,0,126,96,124,6,102
  .BYTE 60,0,0,60,96,124,102,102,60,0
  .BYTE 0,126,6,12,24,48,48,0,0,60
  .BYTE 102,60,102,102,60,0,0,60,102,62
  .BYTE 6,12,56,0,34,10,42,160,162,160
  .BYTE 42,10,136,160,40,10,42,10,40,160
  .BYTE 192,192,192,192,192,192,192,192,0,0
  .BYTE 0,255,0,0,0,0,0,60,102,110
  .BYTE 110,96,62,0,0,24,60,102,102,126
  .BYTE 102,0,0,124,102,124,102,102,124,0
  .BYTE 0,60,102,96,96,102,60,0,0,120
  .BYTE 108,102,102,108,120,0,0,126,96,124
  .BYTE 96,96,126,0,0,126,96,124,96,96
  .BYTE 96,0,0,62,96,96,110,102,62,0
  .BYTE 0,102,102,126,102,102,102,0,0,126
  .BYTE 24,24,24,24,126,0,0,6,6,6
  .BYTE 6,102,60,0,0,102,108,120,120,108
  .BYTE 102,0,0,96,96,96,96,96,126,0
  .BYTE 0,99,119,127,107,99,99,0,0,102
  .BYTE 118,126,126,110,102,0,0,60,102,102
  .BYTE 102,102,60,0,0,124,102,102,124,96
  .BYTE 96,0,0,60,102,102,102,108,54,0
  .BYTE 0,124,102,102,124,108,102,0,0,60
  .BYTE 96,60,6,6,60,0,0,126,24,24
  .BYTE 24,24,24,0,0,102,102,102,102,102
  .BYTE 126,0,0,102,102,102,102,60,24,0
  .BYTE 0,99,99,107,127,119,99,0,0,102
  .BYTE 102,60,60,102,102,0,0,102,102,60
  .BYTE 24,24,24,0,0,126,12,24,48,96
  .BYTE 126,0,0,30,24,24,24,24,30,0
  .BYTE 0,64,96,48,24,12,6,0,0,120
  .BYTE 24,24,24,24,120,0,0,8,28,54
  .BYTE 99,0,0,0,0,0,0,0,0,0
  .BYTE 255,0,0
;
;SCREEN DATA
;
SCDAT
  .BYTE 0,0,0,5,3,1,1,1,3,1
  .BYTE 1,1,3,1,1,1,3,1,1,1
  .BYTE 3,1,1,1,3,1,1,1,3,1
  .BYTE 1,1,3,1,1,8,10,0,0,0
  .BYTE 0,0,0,5,4,0,17,0,17,0
  .BYTE 17,0,17,0,17,0,17,0,17,0
  .BYTE 17,0,17,0,17,0,17,0,17,0
  .BYTE 17,0,17,0,17,11,10,0,0,0
  .BYTE 0,0,0,5,4,0,17,1,6,0
  .BYTE 17,1,6,0,17,1,6,0,17,1
  .BYTE 6,0,17,1,6,0,17,1,6,0
  .BYTE 17,1,6,0,17,11,10,0,0,0
  .BYTE 0,0,0,5,4,0,17,0,17,0
  .BYTE 17,0,17,0,17,0,17,0,17,0
  .BYTE 17,0,17,0,17,0,17,0,17,0
  .BYTE 17,0,17,0,17,11,10,0,0,0
  .BYTE 0,0,0,5,4,0,17,1,6,0
  .BYTE 17,1,6,0,17,1,6,0,17,1
  .BYTE 6,0,17,1,6,0,17,1,6,0
  .BYTE 17,1,6,0,17,11,10,0,0,0
  .BYTE 0,0,0,5,4,0,0,0,0,0
  .BYTE 0,0,0,0,0,0,0,0,0,0
  .BYTE 0,0,17,0,17,0,17,0,17,0
  .BYTE 17,0,17,0,17,11,10,0,0,0
  .BYTE 0,0,0,5,4,0,17,1,6,0
  .BYTE 17,1,6,0,17,1,6,0,17,1
  .BYTE 6,0,17,1,6,0,17,1,6,0
  .BYTE 17,1,6,0,17,11,10,0,0,0
  .BYTE 0,0,0,5,4,0,17,0,17,0
  .BYTE 17,0,17,0,17,0,17,0,17,0
  .BYTE 17,0,17,0,17,0,17,0,17,0
  .BYTE 17,0,17,0,17,11,10,0,0,0
  .BYTE 0,0,0,5,4,0,17,1,6,0
  .BYTE 17,1,6,0,17,1,6,0,17,1
  .BYTE 6,0,17,1,6,0,17,1,6,0
  .BYTE 17,1,6,0,17,11,10,0,0,0
  .BYTE 0,0,0,5,4,0,17,0,17,0
  .BYTE 17,0,17,0,17,0,17,0,17,0
  .BYTE 17,0,17,0,17,0,17,0,17,0
  .BYTE 17,0,17,0,17,11,10,0,0,0
  .BYTE 0,0,0,5,2,1,1,1,2,1
  .BYTE 1,1,2,1,1,1,2,1,1,1
  .BYTE 2,1,1,1,2,1,1,1,2,1
  .BYTE 1,1,2,1,1,9,10,0,0,0
  .BYTE 0,0,87,0,0,0,0,18,18,18
  .BYTE 18,18,26,0,0,0,0,0,0,0
  .BYTE 0,0,0,0,0,0,0,0,0,0
  .BYTE 0,0,0,0,0,0,0,0,0,0
  .BYTE 0,0,0,0,0,0,0,0,0,0
  .BYTE 0,0,0,0,0,0,0,0,0,0
  .BYTE 0,0,0,0,0,0,0,0,0,0
  .BYTE 0,0,0
;
;RUN ADDRESS
;
  *=  $02E0
  .WORD INIT