0100 ;SAVE#D:SNOWA.PT1
0110 ;-------------------
0120 ; part 1 of the game
0130 ;
0140 ; by: Barry Kolbe
0150 ;
0160 ;-------------------
0170     .OPT NO LIST
0180 ;
0190 ;page zero variables
0200 ;
0210 DRY =   $82
0220 PXP =   $83     ;2byter
0230 PYP =   $85     ; "
0240 ADD =   $87
0250 HMV =   $88
0260 CURCHR = $89
0270 VERT =  $8A
0280 EADD =  $8B
0290 EHOLD = $8C
0300 EYX =   $8D
0310 EYY =   $8E
0320 ICY =   $8F
0330 ICX =   $90
0340 VTIME = $91
0350 VFLG =  $92
0360 XSP =   $93
0370 YSP =   $94
0380 RAND =  $95
0390 ICNT =  $96
0400 DATA =  $97
0410 UNIQUE = $98
0420 FTIME = $99     ;7 bytes
0430 CARTIM = $A0    ;6 bytes
0440 RMTIM = $A6     ;6 bytes
0450 ROADC = $AC     ;2 bytes
0460 ROADG = $AE     ;  "
0470 CNT =   $B0
0480 SHD =   $B1
0490 MAPFLG = $B2
0500 FUEL =  $B3     ;3 bytes
0510 LIVES = $B6
0520 DIRF =  $B7
0530 DIRECT = $B8
0540 CARCNT = $B9
0550 ICEON = $BA
0560 Y1  =   $BB
0570 Y2  =   $BC
0580 ICEDIR = $BD
0590 IDECNT = $BE
0600 LEVEL = $BF
0610 FULK =  $C0
0620 ICTL =  $C1
0630 ICTH =  $C2
0640 ICESPEED = $C3
0650 THOUS = $C4
0660 SPSND = $C5
0670 IFLAG = $C6
0680 IISY =  $C7
0690 IIY3 =  $C8
0700 COUNT = $C9     ;these are
0710 IL  =   $CB
0720 TL  =   $CB     ;all
0730 JL  =   $CD
0740 BFL =   $CD
0750 INDR =  $CB     ;2 bytes
0760 IND2 =  $CD
0770 FOFS =  $CF
0780 YH  =   $D0
0790 XD1 =   $D1
0800 XH  =   $D2
0810 ICECNT = $D3
0820 SCRS =  $D4     ;6 bytes
0830 FULX =  $DA     ;6 bytes
0840 FULY =  $E0     ;6 bytes
0850 CARX =  $E6     ;4 bytes
0860 CARY =  $EA     ;4 bytes
0870 OFFSCN = $EE    ;2 bytes
0880 SLENGTH = $F0
0890 EDM =   $F1     ;2
0900 SXP =   $F3
0910 SYP =   $F4
0920 ;
0930 ;OS equates
0940 ;
0950 CIOV =  $E456
0960 ICCOM = $0342
0970 ICBAL = $0344
0980 ICBAH = $0345
0990 ICBLL = $0348
1000 ICBLH = $0349
1010 AUX1 =  $034A
1020 AUX2 =  $034B
1030 SETVBV = $E45C
1040 XITVBV = $E462
1050 RANDOM = $D20A
1060 RTCLOK = $14
1070 CONSOL = $D01F
1080 EOL =   $9B
1090 SEOL =  $BB
1100 PCHR =  54
1110 ;
1120 COLOR0 = $02C4
1130 COLOR1 = $02C5
1140 COLOR2 = $02C6
1150 COLOR3 = $02C7
1160 COLOR4 = $02C8
1170 SDLSTL = $0230
1180 CH  =   $02FC
1190 ;
1200 STICK = $0278
1210 STRIG = $0284
1220 HPOSP0 = $D000
1230 HPOSM0 = $D004
1240 HSCROL = $D404
1250 VSCROL = $D405
1260 HITCLR = $D01E
1270 P0PL =  $D00C
1280 P1PL =  $D00D
1290 ;
1300 ;memory usage
1310 ;
1320 SCNMEM = $9000
1330 PMB =   $8000
1340 SET =   $8C00
1350 MYPMB = $8400
1360 MSMEM = PMB+$0300
1370 P0MEM = MYPMB
1380 P1MEM = MYPMB+$0100
1390 P2MEM = MYPMB+$0200
1400 P3MEM = MYPMB+$0300
1410 CHSET = $8C00
1420 GOVER = $9B00
1430 TXTWIN = $8B00
1440 SCLN =  TXTWIN+20
1450 CHRLN1 = TXTWIN+40
1460 SC2 =   SCNMEM+128
1470 SC3 =   SC2+128
1480 SC4 =   SC3+128
1490 SC5 =   SC4+128
1500 SC6 =   SC5+128
1510 SC7 =   SC6+128
1520 SC8 =   SC7+128
1530 SC9 =   SC8+128
1540 SC10 =  SC9+128
1550 SC11 =  SC10+128
1560 BCKUP = $7FC0
1570 SET2 =  $7D00
1580 SCRLMEM = $7C00
1590 ;credits @ $7b00
1600 ;
1610 ;display list interrupt
1620 ;
1630     *=  PMB
1640 DLI PHA 
1650 DIC LDA #2
1660     STA $D40A
1670     STA $D01A
1680     PLA 
1690     RTI 
1700 ;
1710 ;character set
1720 ;
1730     *=  $8C00
1740     .INCLUDE #D:SNOW.PT5
1750 ;
1760     *=  TXTWIN
1770     .SBYTE " FUEL 150 PLOWS "
1780     .SBYTE "3      SCORE "
1790     .SBYTE "000000     "
1800 ;
1810     *=  GOVER
1820     .SBYTE "  SNOWFLAKES "
1830     .SBYTE "WIN       press "
1840     .SBYTE "START      "
1850 ;
1860 ;display lists ;intro first
1870 ;then game board
1880 ;
1890     *=  $7F00
1900 IDLST .BYTE $70,$70,$70,$70
1910     .BYTE $70,$70,$70,$42
1920     .WORD SNOWMEM
1930     .BYTE $02,$70,$70,$70,$02
1940     .BYTE $02,$70,$70,$70,$70
1950     .BYTE $57
1960 LMS .WORD SCRLMEM
1970     .BYTE $70,$70,$70,$70,$46
1980     .WORD TOPSCORE
1990     .BYTE $41
2000     .WORD IDLST
2010 ;
2020     *=  $7F80
2030 DL1 .BYTE $70,$70,$70
2040     .BYTE $42
2050     .WORD SNOWMEM
2060     .BYTE 2
2070     .BYTE $75
2080 SL1 .WORD SCNMEM
2090     .BYTE $75
2100     .WORD SC2
2110     .BYTE $75
2120     .WORD SC3
2130     .BYTE $75
2140     .WORD SC4
2150     .BYTE $75
2160     .WORD SC5
2170     .BYTE $75
2180     .WORD SC6
2190     .BYTE $75
2200     .WORD SC7
2210     .BYTE $75
2220     .WORD SC8
2230     .BYTE $75
2240     .WORD SC9
2250     .BYTE $75
2260     .WORD SC10
2270     .BYTE $D5
2280     .WORD SC11
2290     .BYTE $46
2300 TMESS .WORD TXTWIN
2310     .BYTE 6,$41
2320     .WORD DL1
2330 ;
2340 ;start of program
2350 ;
2360     *=  $4000
2370 ;
2380 ;save the display list
2390 ;for next levels
2400 ;
2410 BEGIN LDY #50
2420 MDL LDA DL1,Y
2430     STA BCKUP,Y
2440     DEY 
2450     BPL MDL
2460     LDA # >CHSET ;new chrset
2470     STA 756
2480     JSR SETPMG  ;player init
2490 ;
2500     LDX # >VBLNK ;set vbi
2510     LDY # <VBLNK
2520     LDA #7
2530     JSR SETVBV
2540     LDA #0
2550     STA IFLAG   ;intro flag
2560 ;
2570 ;begin new level
2580 ;
2590 NEWBEG LDA #0
2600     STA DIRF
2610     STA MAPFLG
2620     JSR GETDIR
2630     JMP NEWB
2640 NDIRC JSR CLOSE6
2650 ;
2660 NEWB JSR INIT
2670     JSR REPLAY
2680     LDA #3
2690     STA LIVES
2700     LDA #0
2710     STA ICEON
2720     JSR SHOLIV
2730 NLEVL JSR STARTI
2740     JSR FIGLEV
2750     JSR RESFUL
2760     JSR DSPFUL
2770     JSR REPLAY
2780     JSR CLRPM
2790     LDA DIRF
2800     BNE DROK
2810 MAP2 LDA MAPFLG ;intern map
2820     BNE DROK
2830     LDA #1
2840     STA MAPFLG
2850     JSR UNCOM
2860     JMP SKP
2870 DROK JSR GETFIL
2880     JSR LOADMP
2890 SKP JSR FNDFUL
2900     JSR FNDCRS
2910     JSR CNTRDS
2920     JSR COPYDL
2930     JSR SETSCN
2940     LDA #$0B
2950     STA DIRECT
2960     JSR DEFPLR
2970     LDA #1
2980     STA VFLG
2990 ;
3000 ;main loop
3010 ;
3020 MAIN LDA CONSOL
3030     CMP #6
3040     BNE MN2
3050     JMP STKEY
3060 MN2 LDA STICK
3070     STA DIRECT
3080     JSR DEFPLR
3090     STA HITCLR
3100     JSR MOVPLR
3110     JSR REMOVE
3120     LDA 644
3130     BNE NTRG
3140     JSR JMPEDG
3150 NTRG JSR ICESND
3160     LDA P0PL
3170     CMP #12
3180     BCS OUCH
3190     LDA P1PL
3200     CMP #12
3210     BCS OUCH
3220     LDA ROADG+1
3230     CMP ROADC+1
3240     BNE KL
3250     LDA ROADG
3260     CMP ROADC
3270     BNE KL
3280     JSR WAITSM
3290     JMP NLEVL
3300 KL  LDA FUEL
3310     ORA FUEL+1
3320     ORA FUEL+2
3330     BNE KK
3340 OUCH STA HITCLR
3350     JSR REMP23
3360     JSR SPIN
3370     JSR GRESET
3380     STA HITCLR
3390     JSR DELAY
3400     JMP KK
3410 OOPS JMP GAMOVR
3420 KK  LDA LIVES
3430     BEQ OOPS
3440     LDA CH
3450     CMP #$FF
3460     BEQ NOPAUS
3470     JSR PAUSE
3480 NOPAUS JMP MAIN
3490 ;
3500 ;set pmg
3510 ;
3520 SETPMG LDA #62
3530     STA 559
3540     LDA #17     ;5th enable
3550     STA 623
3560     LDA #3
3570     STA 53277
3580     LDA # >PMB
3590     STA 54279
3600     LDA #$28    ;yellow
3610     STA 704
3620     LDA #6      ;black
3630     STA 705
3640     LDA #$A6
3650     STA 706
3660     STA 707
3670     LDA #$80
3680     STA PXP
3690     LDA #$70
3700     STA PYP
3710     LDA #1
3720     STA 53258
3730     STA 53259
3740     RTS 
3750 ;
3760 ;clear pm area
3770 ;
3780 CLRPM LDY #$FF
3790     LDA #0
3800 CPM STA P0MEM,Y
3810     STA P1MEM,Y
3820     STA P2MEM,Y
3830     STA P3MEM,Y
3840     STA MSMEM,Y
3850     DEY 
3860     CPY #$FF
3870     BNE CPM
3880     RTS 
3890 ;
3900 ;define plrs
3910 ;
3920 DEFPLR LDX #3
3930     LDA DIRECT
3940 DF1 CMP DIRTAB,X
3950     BEQ DFOK
3960     DEX 
3970     BPL DF1
3980     RTS 
3990 DFOK LDA PD0L,X
4000     STA JL
4010     LDA PD0H,X
4020     STA JL+1
4030     LDA PD1L,X
4040     STA IL
4050     LDA PD1H,X
4060     STA IL+1
4070     TXA 
4080     PHA 
4090     LDA PYP
4100     STA Y1
4110     CLC 
4120     ADC YTB,X
4130     STA PYP+1
4140     STA Y2
4150     TAY 
4160     LDA #0
4170     STA P1MEM-1,Y
4180     LDY #0
4190 DFP LDA (JL),Y
4200     LDX Y1
4210     STA P0MEM,X
4220     LDA (IL),Y
4230     LDX Y2
4240     STA P1MEM,X
4250     INY 
4260     INC Y1
4270     INC Y2
4280     CPY #16
4290     BNE DFP
4300     LDX Y2
4310     STA P1MEM,X
4320     LDX PXP
4330     STX HPOSP0
4340     PLA 
4350     TAX 
4360     LDA PXP
4370     CLC 
4380     ADC XTB,X
4390     STA PXP+1
4400     STA HPOSP0+1
4410     RTS 
4420 ;
4430 DIRTAB .BYTE 11,7,14,13
4440 XTB .BYTE $FF,$01,$00,$00
4450 YTB .BYTE $00,$00,$FF,$01
4460 ;
4470 ;player definitions & tables
4480 ;
4490 PD0L .BYTE  <P0D1, <P0D2, <P0D3, <P0D4
4500 PD0H .BYTE  >P0D1, >P0D2, >P0D3, >P0D4
4510 PD1L .BYTE  <P1D1, <P1D2, <P1D3, <P1D4
4520 PD1H .BYTE  >P1D1, >P1D2, >P1D3, >P1D4
4530 P0D1 .BYTE $00,$00,$00,$FF
4540     .BYTE $FF,$76,$76,$76
4550     .BYTE $76,$76,$76,$FF
4560     .BYTE $FF,$00,$00,$00
4570 P0D2 .BYTE $00,$00,$00,$FF
4580     .BYTE $FF,$6E,$6E,$6E
4590     .BYTE $6E,$6E,$6E,$FF
4600     .BYTE $FF,$00,$00,$00
4610 P0D3 .BYTE $00,$66,$66,$7E
4620     .BYTE $7E,$7E,$7E,$7E
4630     .BYTE $7E,$66,$66,$66
4640     .BYTE $7E,$7E,$66,$00
4650 P0D4 .BYTE $00,$66,$7E,$7E
4660     .BYTE $66,$66,$66,$7E
4670     .BYTE $7E,$7E,$7E,$7E
4680     .BYTE $7E,$66,$66,0
4690 ;
4700 P1D1 .BYTE $00,$AA,$AA,$80
4710     .BYTE $80,$84,$84,$84
4720     .BYTE $84,$84,$84,$80
4730     .BYTE $80,$AA,$AA,$00
4740 P1D2 .BYTE $00,$FD,$FD,$01
4750     .BYTE $01,$61,$61,$61
4760     .BYTE $61,$61,$61,$01
4770     .BYTE $01,$FD,$FD,$00
4780 P1D3 .BYTE 0,$FF,$FF,$00
4790     .BYTE $99,$99,$18,$18
4800     .BYTE $99,$99,$18,$18
4810     .BYTE $99,$99,$00,$00
4820 P1D4 .BYTE $00,$00,$81,$99
4830     .BYTE $18,$18,$99,$99
4840     .BYTE $18,$18,$99,$99
4850     .BYTE $00,$FF,$FF,$00
4860 ;
4870 ;delay
4880 ;
4890 LDL LDY #19
4900     BNE DLN
4910 DELAY LDY #7
4920 DLN JSR WAIT
4930     DEY 
4940     BNE DLN
4950     RTS 
4960 ;
4970 ;initialize
4980 ;
4990 ;set up 128 table
5000 INIT LDY #0
5010     LDA # <SCNMEM
5020     STA M128L
5030     LDA # >SCNMEM
5040     STA M128H
5050 TLP LDA M128L,Y
5060     CLC 
5070     ADC #128
5080     STA M128L+1,Y
5090     LDA M128H,Y
5100     ADC #0
5110     STA M128H+1,Y
5120     INY 
5130     CPY #33
5140     BNE TLP
5150 ;
5160     LDX #7      ;score & fuel
5170     LDA #$10    ;IC $10
5180 SCF STA SCRS,X
5190     DEX 
5200     BPL SCF
5210     STA THOUS
5220     JSR RESFUL
5230     LDA #3      ;set lives
5240     STA LIVES
5250     LDA #$13
5260     STA TXTWIN+16
5270     LDA #$60
5280     STA ICECNT
5290     LDA #$FF
5300     STA LEVEL
5310     RTS 
5320 ;
5330 CLRTAB .BYTE $D8,$44,$0A,$46,$00
5340 ;
5350 STSCRL LDA # >SL1
5360     STA JL+1
5370     LDA # <SL1
5380     STA JL
5390     RTS 
5400 ;
5410 ;get scn pos
5420 ;
5430 WHER LDY DRY
5440 WHERE LDA M128L,Y
5450     STA JL
5460     LDA M128H,Y
5470     STA JL+1
5480     RTS 
5490 ;
5500 ;shadow scrols
5510 ;
5520 SMX .BYTE 22    ;pos on scrn
5530 SMY .BYTE 4
5540 ;
5550 ;move
5560 ;
5570 SCROLL LDA DIRECT
5580 ;
5590 MMR CMP #7      ;rt?
5600     BNE MML
5610     JSR LOOKR
5620     BCC RA1
5630     RTS 
5640 RA1 LDA SXP
5650     CMP #83
5660     BCC HO
5670     RTS 
5680 HO  LDA #1
5690     STA VERT
5700     JSR PLWSND
5710 KB  LDA #1
5720     STA ADD
5730     JSR CORSH
5740     INC SMX
5750     INC SXP
5760     LDX #3
5770 KA  STX HSCROL
5780     JSR WAIT
5790     JSR TRACKR
5800     DEX 
5810     BPL KA
5820     DEC VERT
5830     LDA VERT
5840     BPL KB
5850 FULOUT JSR SFUEL
5860     JSR OFF2
5870     JSR CKFTIM
5880     RTS 
5890 ;
5900 MML CMP #11
5910     BNE MUP
5920     JSR LOOKL
5930     BCC LA1
5940     RTS 
5950 LA1 LDA SXP
5960     BNE HQ
5970     RTS 
5980 HQ  LDA #1
5990     STA VERT
6000     JSR PLWSND
6010 KD  LDX #0
6020 KC  STX HSCROL
6030     JSR WAIT
6040     JSR TRACKL
6050     INX 
6060     CPX #4
6070     BNE KC
6080     LDA #$FF
6090     STA ADD
6100     LDX #0
6110     STX HSCROL
6120     JSR CORSH
6130     DEC SXP
6140     DEC SMX
6150     DEC VERT
6160     LDA VERT
6170     BPL KD
6180     JMP FULOUT
6190 ;
6200 ;coarse h scrol
6210 ;
6220 CORSH LDY #0
6230 CSA LDA SL1,Y
6240     CLC 
6250     ADC ADD
6260     STA SL1,Y
6270     INY 
6280     INY 
6290     INY 
6300     CPY #33
6310     BNE CSA
6320     RTS 
6330 ;
6340 ;up
6350 ;
6360 MUP CMP #14
6370     BNE MDN
6380     JSR LOOKU
6390     BCC UA1
6400     RTS 
6410 UA1 LDA SYP
6420     BEQ NOM
6430     JSR PLWSND
6440     LDA #$FF
6450     STA ADD
6460     JSR CORSV
6470     DEC SYP
6480     DEC SMY
6490     LDX #15
6500 U1  STX VSCROL
6510     JSR WAIT
6520     JSR TRACKU
6530     DEX 
6540     BPL U1
6550     LDA #0
6560     STA VSCROL
6570     JMP FULOUT
6580     RTS 
6590 ;
6600 ;down
6610 ;
6620 MDN CMP #13
6630     BNE NOM
6640     JSR LOOKD
6650     BCC DA1
6660     RTS 
6670 DA1 LDA SYP
6680     CMP #9
6690     BCC D1
6700     RTS 
6710 D1  JSR PLWSND
6720     LDX #0
6730 D2  STX VSCROL
6740     JSR WAIT
6750     JSR TRACKU
6760     INX 
6770     CPX #16
6780     BNE D2
6790     LDX #0
6800     STX VSCROL
6810     LDA #1
6820     STA ADD
6830     JSR CORSV
6840     INC SYP
6850     INC SMY
6860     JMP FULOUT
6870 NOM RTS 
6880 ;
6890 ;coarse vrt scrl
6900 ;
6910 CORSV LDA ADD
6920     BMI CSV
6930     LDY #0
6940 CVL LDA SL1,Y
6950     CLC 
6960     ADC #$80
6970     STA SL1,Y
6980     INY 
6990     LDA SL1,Y
7000     ADC #0
7010     STA SL1,Y
7020     INY 
7030     INY 
7040     CPY #33
7050     BNE CVL
7060     RTS 
7070 ;
7080 CSV LDY #0
7090 CVP LDA SL1,Y
7100     SEC 
7110     SBC #$80
7120     STA SL1,Y
7130     INY 
7140     LDA SL1,Y
7150     SBC #0
7160     STA SL1,Y
7170     INY 
7180     INY 
7190     CPY #33
7200     BNE CVP
7210     RTS 
7220 ;
7230 ;wait a jiffy
7240 ;
7250 WAIT LDA #0
7260     STA $14
7270 WW2 LDA $14
7280     BEQ WW2
7290     RTS 
7300 ;
7310 ;fine scrl plr
7320 ;
7330 MOVPLR LDA DIRECT
7340     CMP #7
7350     BNE MLL
7360     LDA PXP
7370     CMP #$7C
7380     BCC GOR
7390     LDA SXP
7400     CMP #83
7410     BCS GOR
7420     JMP MOUT
7430 GOR LDA PXP
7440     CMP #$C8
7450     BCS MVRET
7460     JSR LOOKR
7470     BCC GOR1
7480     RTS         ;nope
7490 GOR1 JSR PLWSND
7500     LDY #7
7510 RL1 INC PXP
7520     LDX PXP
7530     STX HPOSP0
7540     INC PXP+1
7550     LDX PXP+1
7560     STX HPOSP0+1
7570     JSR WAIT
7580     JSR TRACKR
7590     DEY 
7600     BPL RL1
7610     INC SMX
7620     INC SMX
7630     JMP FULOUT
7640 MOUT JSR SCROLL
7650 MVRET RTS 
7660 ;
7670 MLL CMP #11
7680     BNE MDD
7690     JSR LOOKL
7700     BCC GOL2
7710     RTS 
7720 GOL2 LDA PXP
7730     CMP #132    ;124+8
7740     BCS GOL1
7750     LDA SXP
7760     BNE MOUT
7770 GOL LDA PXP
7780     CMP #$30
7790     BEQ MVRET
7800     BCC MVRET
7810 GOL1 JSR PLWSND
7820     LDY #7
7830 LL1 DEC PXP
7840     LDX PXP
7850     STX HPOSP0
7860     DEC PXP+1
7870     LDX PXP+1
7880     STX HPOSP0+1
7890     JSR WAIT
7900     JSR TRACKL
7910     DEY 
7920     BPL LL1
7930     DEC SMX
7940     DEC SMX
7950     JMP FULOUT
7960 ;
7970 MDD CMP #13
7980     BNE MUU
7990     JSR LOOKD
8000     BCC GD3
8010     RTS 
8020 GD3 LDA PYP
8030     CMP #$60
8040     BCC GDN
8050     LDA SYP
8060     CMP #9
8070     BCS GDN
8080     JMP MOUT
8090 GDN LDA PYP
8100     CMP #$C0
8110     BCS MVRET
8120     LDA #15
8130     STA VERT
8140     JSR PLWSND
8150 GD2 LDA PYP
8160     STA Y1
8170     LDA PYP+1
8180     STA Y2
8190     TAY 
8200     LDA #0
8210     STA P1MEM,Y ;eras top
8220     LDX #15
8230 GD1 LDY Y1
8240     LDA P0MEM+15,Y
8250     STA P0MEM+16,Y
8260     LDY Y2
8270     LDA P1MEM+15,Y
8280     CMP #$18
8290     BNE FOA
8300     LDA #$99
8310     BNE FOB
8320 FOA CMP #$99
8330     BNE FOB
8340     LDA #$18
8350 FOB STA P1MEM+16,Y
8360     DEC Y1
8370     DEC Y2
8380     DEX 
8390     BPL GD1
8400     INC PYP
8410     INC PYP+1
8420     JSR WAIT
8430     DEC VERT
8440     LDA VERT
8450     BPL GD2
8460     INC SMY
8470     JMP FULOUT
8480 ;
8490 ;
8500 MUU CMP #14
8510     BEQ MU3
8520 GU4 JMP MVRET
8530 MU3 JSR LOOKU
8540     BCC MU4
8550     RTS 
8560 MU4 LDA PYP
8570     CMP #$70
8580     BCS GUU
8590     LDA SYP
8600     BEQ GUU
8610     JMP MOUT
8620 GUU LDA PYP
8630     CMP #$30
8640     BNE GU5
8650     JMP MOUT
8660 GU5 JSR PLWSND
8670     LDA #15
8680     STA VERT
8690 GU2 LDY PYP
8700     LDX #15
8710 GU1 LDA P0MEM,Y
8720     STA P0MEM-1,Y
8730     LDA P1MEM,Y
8740     CMP #$18
8750     BNE FOC
8760     LDA #$99
8770     BNE FOD
8780 FOC CMP #$99
8790     BNE FOD
8800     LDA #$18
8810 FOD STA P1MEM-1,Y
8820     INY 
8830     DEX 
8840     BPL GU1
8850     JSR WAIT
8860     DEC PYP
8870     DEC VERT
8880     LDA VERT
8890     BPL GU2
8900     DEC SMY
8910     JMP FULOUT
8920 ;
8930 ;locate :result in curchr
8940 ;
8950 LOOKR LDY SMY
8960     JSR WHERE
8970     LDY SMX
8980     INY 
8990     INY 
9000 LKRET LDA (JL),Y
9010     STA CURCHR
9020     JSR CKCHAR
9030     RTS 
9040 ;
9050 LOOKL LDY SMY
9060     JSR WHERE
9070     LDY SMX
9080     DEY 
9090     DEY 
9100     JMP LKRET
9110 ;
9120 LOOKD LDY SMY
9130     INY 
9140     JSR WHERE
9150     LDY SMX
9160     JMP LKRET
9170 ;
9180 LOOKU LDY SMY
9190     DEY 
9200     JSR WHERE
9210     LDY SMX
9220     JMP LKRET
9230 ;
9240 ;erase chr beneath dozer
9250 ;repalce with next char.
9260 ;which is a road w/o snow
9270 ;
9280 REMOVE LDY SMY
9290     JSR WHERE
9300     LDY SMX
9310     LDA (JL),Y
9320     LDX #15
9330 RB1 CMP ROADS,X
9340     BEQ SF5
9350     DEX 
9360     BPL RB1
9370     JMP SF6
9380 SF5 CMP #$1B    ;cng car to road
9390     BEQ SF8
9400     CMP #$1D
9410     BNE SF7
9420 SF8 PHA         ;save car
9430     LDA #$61
9440     STA (JL),Y
9450     INY 
9460     STA (JL),Y
9470     JSR BONSCR
9480     JSR HORN
9490     PLA 
9500     CMP #$1B
9510     BEQ SFA
9520     BNE SF6
9530 SF7 TAX 
9540     INX 
9550     TXA 
9560     STA (JL),Y
9570     INY 
9580     LDA (JL),Y
9590     TAX 
9600     INX 
9610     TXA 
9620     STA (JL),Y
9630     CMP #$0B    ;    fuel?
9640     BEQ SF6
9650 SFA INC ROADG
9660     BNE SH1
9670     INC ROADG+1
9680 ;
9690 SH1 JSR DOSCOR  ;show score
9700 ;
9710 SF6 LDA CURCHR
9720     CMP #$08    ;fuel?
9730     BNE CAR?
9740 ;
9750     INC CURCHR  ;empty fuel
9760     LDY SMY
9770     JSR WHERE
9780     LDX FOFS    ;get pos.
9790 FFA LDA JL+1
9800     CMP FULY,X
9810     BEQ FFB
9820 FFC DEX 
9830     BPL FFA
9840     RTS         ;shouldnt happen
9850 FFB LDA SMX     ;put it on
9860     CLC         ;screen
9870     ADC JL
9880     CMP FULX,X
9890     BNE FFC
9900     LDA #100    ;got it
9910     STA FTIME,X ;set timer
9920     JSR FILSND  ;sound
9930     JSR RESFUL  ;show it
9940     JSR DSPFUL
9950 SF2 RTS 
9960 ;
9970 ;hit a car
9980 ;
9990 CAR? LDY SMY    ;find out
010000   JSR WHERE   ;which one
010010   LDX CARCNT
010020   BEQ SF2
010030 CB1 LDA JL+1
010040   CMP CARY,X
010050   BEQ CB2
010060 CB3 DEX 
010070   BPL CB1
010080   RTS         ;nope
010090 CB2 LDA JL
010100   CLC 
010110   ADC SMX
010120   CMP CARX,X
010130   BNE CB3
010140   LDA #50     ;set timer
010150   STA CARTIM,X
010160   RTS 
010170 ;
010180 ;road,fuel,car chrs
010190 ; 8 = fuel $1b= car
010200 ;
010210 ROADS .BYTE $60,$62,$64,$66
010220   .BYTE $68,$6A,$6C,$6E
010230   .BYTE $70,$72,$74,$76
010240   .BYTE $78,$08,$1B,$1D
010250   .BYTE $61,$63,$65,$67,$69
010260   .BYTE $6B,$6D,$6F,$71
010270   .BYTE $73,$75,$77,$79
010280 ;
010290 ;check if about to move
010300 ;onto a valid char.
010310 ;
010320 CKCHAR LDX #28
010330 CK1 CMP ROADS,X
010340   BEQ CROK
010350   DEX 
010360   BPL CK1
010370   SEC         ;no move
010380   RTS 
010390 CROK CLC      ;move ok
010400   RTS 
010410 ;
010420 ;decrease fuel
010430 ;
010440 SFUEL DEC FUEL+2
010450   LDA FUEL+2
010460   ORA FUEL+1
010470   ORA FUEL
010480   BEQ SF3
010490   LDA FUEL+2
010500   BPL SF3
010510   LDA #9
010520   STA FUEL+2
010530   DEC FUEL+1
010540   LDA FUEL+1
010550   BPL SF3
010560   LDA #9
010570   STA FUEL+1
010580   DEC FUEL
010590 SF3 JSR DSPFUL
010600 FRET RTS 
010610 ;
010620 ;show fuel left
010630 ;
010640 DSPFUL LDX #2
010650 DS LDA FUEL,X
010660   ORA #$10
010670   STA TXTWIN+6,X
010680   DEX 
010690   BPL DS
010700   RTS 
010710 ;
010720 ;wait some
010730 ;
010740 WAITSM LDA #0
010750   LDX #15     ;15 secs
010760   STA VFLG
010770 WSM JSR LDL
010780   DEX 
010790   BPL WSM
010800   RTS 
010810 ;
010820 ;pt2 is rest of game
010830 ;pt3 is the screen maker
010840 ;pt4 is the introduction
010850 ;
010860   .INCLUDE #D:SNOW.PT2
010870   .INCLUDE #D:SNOW.PT4
010880   .INCLUDE #D:SNOW.PT3
010890 ;
010900 ;variables
010910 ;
010920 RANDS     16
010930 DBUF     20
010940 EDGFLG .BYTE 1
010950 M128L     36
010960 M128H     36
010970   *=  $02E0
010980   .WORD BEGIN
010990   .END