10 ;EFT VERSION 1.8I (INTERRUPT) 11/30/81 COPYRIGHT CHRIS CRAWFORD 1981›20 ;›30 ;Page zero RAM›40 ;›50 RTCLKL=$14›60 ATRACT=$4D›70 DRKMSK=$4E›80 COLRSH=$4F›90  *=$B0›0100 ;›0110 ;These locations are used by the interrupt service routine›0120 ;›0130 DLSTPT *=*+2 Zero page pointer to display list›0140 MAPLO *=*+1›0150 MAPHI *=*+1›0160 CORPS *=*+1 number of unit under window›0170 CURSXL *=*+1›0180 CURSXH *=*+1›0190 CURSYL *=*+1 cursor coordinates on screen (map frame)›0200 CURSYH *=*+1›0210 OFFLO *=*+1 How far to offset new LMS value›0220 OFFHI *=*+1›0230 TEMPI *=*+1 An all-purpose temporary register›0240 CNT1 *=*+1 DLI counter›0250 CNT2 *=*+1 DLI counter for movable map DLI›0260 CHUNKX *=*+1 cursor coordinates (pixel frame)›0270 CHUNKY *=*+1›0280 ;›0290 ;THIS VALUE IS USED BY MAINLINE ROUTINE AND INTERRUPT›0300 ;›0310 TURN=$C9›0320 ;›0330 ;OS locations (see OS manual)›0340 ;›0350 PCOLR0=$02C0›0360 STICK=$0278›0370 CH=$2FC›0380 ;›0390 ;HARDWARE LOCATIONS›0400 ;›0410 HPOSP0=$D000›0420 HPOSP1=$D001›0430 HPOSP2=$D002›0440 HPOSP3=$D003›0450 TRIG0=$D010›0460 TRIG1=$D011›0470 TRIG2=$D012›0480 COLPF0=$D016›0490 COLPF1=$D017›0500 COLPF2=$D018›0510 COLBAK=$D01A›0520 CONSOL=$D01F›0530 AUDF1=$D200›0540 AUDC1=$D201›0550 HSCROLL=$D404›0560 VSCROLL=$D405›0570 WSYNC=$D40A›0580 CHBASE=$D409›0590 SETVBV=$E45C›0600 XITVBV=$E462›0610 ;›0620 ;Page 6 usage›0630 ;›0640  *=$0600›0650 ;first come locations used by the interrupt service routine›0660 XPOSL *=*+1 Horizontal position of›0670 YPOSL *=*+1 Vertical position of›0680 YPOSH *=*+1 upper left corner of screen window›0690 SCY *=*+1 vert position of cursor (player frame)›0700 SHPOS0 *=*+1 shadows player 0 position›0710 TRCOLR *=*+1›0720 EARTH *=*+1›0730 ICELAT *=*+1›0740 SEASN1 *=*+1›0750 SEASN2 *=*+1›0760 SEASN3 *=*+1›0770 DAY *=*+1›0780 MONTH *=*+1›0790 YEAR *=*+1›0800 BUTFLG *=*+1›0810 BUTMSK *=*+1›0820 TYL *=*+1›0830 TYH *=*+1›0840 DELAY *=*+1 acceleration delay on scrolling›0850 TIMSCL *=*+1 frame to scroll in›0860 TEMPLO *=*+1 temporary›0870 TEMPHI *=*+1›0880 BASEX *=*+1 start position for arrow (player frame)›0890 BASEY *=*+1›0900 STEPX *=*+1 intermediate position of arrow›0910 STEPY *=*+1›0920 STPCNT *=*+1 which intermediate steps arrow is on›0930 ORDCNT *=*+1 which order arrow is showing›0940 ORD1 *=*+1 orders record›0950 ORD2 *=*+1›0960 ARRNDX *=*+1 arrow index›0970 HOWMNY *=*+1 how many orders for unit under cursor›0980 KRZX *=*+1 maltakreuze coords (player frame)›0990 KRZY *=*+1›1000 DBTIMR *=*+1 joystick debounce timer›1010 STICKI *=*+1 coded value of stick direction (0-3)›1020 ERRFLG *=*+1›1030 KRZFLG *=*+1›1040 STKFLG *=*+1›1050 HITFLG *=*+1›1060 TXL *=*+1 temporary values---slightly shifted›1070 TXH *=*+1›1080 HANDCP=$68F›1090 ;›1100  *=$5200›1110 PLYR0 *=*+128›1120 PLYR1 *=*+128›1130 PLYR2 *=*+128›1140 PLYR3 *=*+128›1150 CORPSX *=*+159 x-coords of all units (pixel frame)›1160 CORPSY *=*+159 y-coords of all units (pixel frame)›1170 MSTRNG *=*+159 muster strengths›1180 CSTRNG *=*+159 combat strengths›1190 SWAP *=*+159 terrain code underneath unit›1200 ARRIVE *=*+159 turn of arrival›1210 WORDS *=*+272 various words for messages›1220 CORPT *=*+159 codes for unit types›1230 CORPNO *=*+159 ID numbers of units›1240 HDIGIT *=*+256 tables for displaying numbers (hundreds)›1250 TDIGIT *=*+256 tens tables›1260 ODIGIT *=*+256 ones tables›1270 TXTTBL *=*+96 more text›1280 MONLEN *=*+13 table of month lengths›1290 HMORDS *=*+159 how many orders each unit has in queue›1300 WHORDS *=*+159 what the orders are›1310 WHORDH *=*+159›1320 BEEPTB *=*+4 table of beep tones›1330 ERRMSG *=*+128 table of error messages›1340 XOFF *=*+4 offsets for moving maltakreuze›1350 YOFF *=*+4›1360 MASKO *=*+4 mask values for decoding orders›1370 XADD *=*+4 offsets for moving arrow›1380 YADD *=*+4›1390 TRTAB *=*+13›1400 MLTKRZ *=*+8 maltese cross shape›1410 ;›1420 ;RAM from $6000 to $6430 is taken up by›1430 ;character sets and the display list›1440 ;›1450  *=$6431›1460 ARRTAB *=*+32 arrow shapes›1470  *=$6450›1480 TXTWDW *=$6CB1›1490 ;›1500 STKTAB *=*+16 a joystick decoding table›1510 SSNCOD *=*+12›1520 TRNTAB *=*+60›1530 BHX1 *=*+22›1540 BHY1 *=*+22›1550 BHX2 *=*+22›1560 BHY2 *=*+22›1570 EXEC *=*+159›1580 ;›1590 ;everything in here is taken up by the map data›1600 ;›1610 ;›1620 ;This is the vertical blank interrupt routine›1630 ;It reads the joystick and scrolls the screen›1640 ;›1650  *=$7400›1660  LDA TRIG1 check for break button›1670  BNE Z30 no, check next›1680  LDY #62 reset 60 Hertz vector›1690  LDX #233›1700  LDA #7›1710  JSR SETVBV›1720  PLA reset stack›1730  PLA›1740  PLA›1750  JMP $7210 break routine›1760 Z30 LDA HANDCP›1770  BEQ A31›1780  LDA TRIG0›1790  BEQ A31›1800  LDA #$08›1810  STA CONSOL›1820  LDA CONSOL›1830  AND #$04›1840  BNE A31›1850  STA HANDCP›1860  LDA #$30›1870  STA $7B7A my trademark›1880  LDX #$36›1890 LOOPJ LDA MSTRNG,X›1900  STA TEMPI›1910  LSR A›1920  ADC TEMPI›1930  BCC A22›1940  LDA #$FF›1950 A22 STA MSTRNG,X›1960  DEX›1970  BNE LOOPJ›1980 ;›1990 ;›2000 A31 LDA TRIG0 button status›2010  ORA BUTMSK button allowed?›2020  BEQ X17›2030  LDA BUTFLG no button now; previous status›2040  BNE X23›2050  JMP NOBUT›2060 X23 LDA #$58 button just released›2070  STA PCOLR0›2080  LDA #$00›2090  STA BUTFLG›2100  STA KRZFLG›2110  STA AUDC1›2120  LDX #$52›2130 LOOP8 STA TXTWDW+8,X clear text window›2140  DEX›2150  BPL LOOP8›2160  LDA #$08›2170  STA DELAY›2180  CLC›2190  ADC RTCLKL›2200  STA TIMSCL›2210  JSR SWITCH›2220  LDA #$00›2230  STA CORPS›2240  JSR CLRP1›2250  JSR CLRP2›2260  JMP ENDISR›2270 X17 STA ATRACT button is pressed›2280  LDA STICK›2290  AND #$0F›2300  EOR #$0F›2310  BEQ X20 joystick active?›2320  JMP ORDERS yes›2330 X20 STA DBTIMR no, set debounce›2340  STA AUDC1›2350  STA STKFLG›2360  LDA BUTFLG›2370  BNE BUTHLD is this the first button pass›2380  JMP FBUTPS yes›2390 BUTHLD JSR ERRCLR no, clear errors›2400 X61 LDA HITFLG›2410  BEQ X63 anybody in the window?›2420  JMP ENDISR no›2430 X63 LDA CH›2440  CMP #$21›2450  BNE X80 space bar pressed?›2460  LDX CORPS yes, check for Russian›2470  CPX #$37›2480  BCS X80›2490  LDA #$00›2500  STA CH›2510  STA HMORDS,X clear out orders›2520  STA HOWMNY›2530  STA STPCNT›2540  LDA #$01›2550  STA ORDCNT›2560  JSR CLRP1›2570  JSR CLRP2›2580  LDA BASEX›2590  STA STEPX›2600  LDA BASEY›2610  STA STEPY›2620 X80 LDA RTCLKL›2630  AND #$03›2640  BEQ X54 time to move arrow?›2650  JMP ENDISR no›2660 X54 LDY HOWMNY yes›2670  BNE X65 any orders to show?›2680  JMP PCURSE no, go ahead to maltakreuze›2690 X65 JSR CLRP1 yes, clear old arrow›2700  LDA ORDCNT›2710  LDX #$00 assume first byte›2720  CMP #$05›2730  BCC X52 second byte or first?›2740  INX second byte›2750 X52 AND #$03 isolate bit pair index›2760  TAY›2770  LDA BITTAB,Y get mask›2780 X50 AND ORD1,X get orders›2790 ;›2800 ;right justify orders›2810 ;›2820  DEY›2830  BPL X51›2840  LDY #$03›2850 X51 BEQ X53›2860 LOOP21 LSR A›2870  LSR A›2880  DEY›2890  BNE LOOP21›2900 X53 STA ARRNDX›2910  ASL A›2920  ASL A›2930  ASL A›2940 ;get arrow image and store it to player RAM›2950  TAX›2960  LDY STEPY›2970 X55 LDA ARRTAB,X›2980  CPY #$80›2990  BCS X43›3000  STA PLYR1,Y›3010 X43 INX›3020  INY›3030  TXA›3040  AND #$07›3050  BNE X55›3060 ;›3070  LDA STEPX position arrow›3080  STA HPOSP1›3090 ;›3100 ;now step arrow›3110 ;›3120  LDX ARRNDX›3130  LDA STEPX›3140  CLC›3150  ADC XADD,X›3160  STA STEPX›3170  LDA STEPY›3180  CLC›3190  ADC YADD,X›3200  STA STEPY›3210 ;›3220  INC STPCNT next step›3230  LDA STPCNT›3240  AND #$07›3250  BNE X59 if not done end ISR›3260  STA STPCNT end of steps›3270  INC ORDCNT next order›3280  LDA ORDCNT›3290  CMP HOWMNY last order?›3300  BCC X59 no, out›3310  BEQ X59 no, out›3320  LDA #$01›3330  STA ORDCNT yes, reset to start of arrow's path›3340 ;›3350 ;display maltese cross ('maltakreuze' or KRZ)›3360 ;›3370 PCURSE LDY STEPY›3380  STY KRZY›3390  LDA #$FF›3400  STA KRZFLG›3410  LDX #$00›3420 LOOP24 LDA MLTKRZ,X›3430  CPY #$80›3440  BCS X44›3450  STA PLYR2,Y›3460 X44 INY›3470  INX›3480  CPX #$08›3490  BNE LOOP24›3500  LDA STEPX›3510  SEC›3520  SBC #$01›3530  STA KRZX›3540  STA HPOSP2›3550  JSR CLRP1 clear arrow›3560  LDA BASEX reset arrow's coords›3570  STA STEPX›3580  LDA BASEY›3590  STA STEPY›3600 ;›3610 X59 JMP ENDISR›3620 ;›3630 ;FIRST BUTTON PASS›3640 ;looks for a unit inside cursor›3650 ;if there is one, puts unit info into text window›3660 ;›3670 FBUTPS LDA #$FF›3680  STA BUTFLG›3690 ;›3700 ;first get coords of center of cursor (map frame)›3710 ;›3720 X24 LDA CURSXL›3730  CLC›3740  ADC #$06›3750  STA TXL›3760  LDA CURSXH›3770  ADC #$00›3780  STA TXH›3790  LDA CURSYL›3800  CLC›3810  ADC #$09›3820  STA TYL›3830  LDA CURSYH›3840  ADC #$00›3850  STA TYH›3860  LDA TXH›3870  LSR A›3880  LDA TXL›3890  ROR A›3900  LSR A›3910  LSR A›3920 ;›3930 ;coords of cursor (pixel frame)›3940 ;›3950  STA CHUNKX›3960  LDA TYH›3970  LSR A›3980  TAX›3990  LDA TYL›4000  ROR A›4010  TAY›4020  TXA›4030  LSR A›4040  TYA›4050  ROR A›4060  LSR A›4070  LSR A›4080  STA CHUNKY›4090 ;›4100 ;now look for a match with unit coordinates›4110 ;›4120  LDX #$9E›4130 LOOP6 CMP CORPSY,X›4140  BEQ MAYBE›4150 X16 DEX›4160  BNE LOOP6›4170  STX CORPS no match obtained›4180  DEX›4190  STX HITFLG›4200  JMP ENDISR›4210 ;›4220 MAYBE LDA CHUNKX›4230  CMP CORPSX,X›4240  BNE X35›4250  LDA ARRIVE,X›4260  BMI X35›4270  CMP TURN›4280  BCC MATCH›4290  BEQ MATCH›4300 X35 LDA CHUNKY›4310  JMP X16›4320 ;›4330 ;match obtained›4340 ;›4350 MATCH LDA #$00›4360  STA HITFLG note match›4370  STA CH›4380  LDA #$5C›4390  STA PCOLR0 light up cursor›4400 ;›4410 ;display unit specs›4420 ;›4430  STX CORPS›4440  LDY #$0D›4450  LDA CORPNO,X ID number›4460  JSR DNUMBR›4470  INY›4480  LDX CORPS›4490  LDA CORPT,X first name›4500  STA TEMPI›4510  AND #$F0›4520  LSR A›4530  JSR ENTRY2›4540  LDA TEMPI›4550  AND #$0F second name›4560  CLC›4570  ADC #$08›4580  JSR DWORDS›4590  LDA #$1E›4600  LDX CORPS›4610  CPX #$37›4620  BCS X26›4630  LDA #$1D›4640 X26 JSR DWORDS display unit size (corps or army)›4650  LDY #$38›4660  LDA #$1F "MUSTER"›4670  JSR DWORDS›4680  DEY›4690  LDA #$1A ":"›4700  STA TXTWDW,Y›4710  INY›4720  INY›4730  LDX CORPS›4740  LDA MSTRNG,X muster strength›4750  JSR DNUMBR›4760  INY›4770  INY›4780  LDA #$20 "COMBAT"›4790  JSR DWORDS›4800  LDA #$21 "STRENGTH"›4810  JSR DWORDS›4820  DEY›4830  LDA #$1A ":"›4840  STA TXTWDW,Y›4850  INY›4860  INY›4870  LDX CORPS›4880  LDA CSTRNG,X combat strength›4890  JSR DNUMBR›4900 X27 JSR SWITCH flip unit with terrain›4910  LDA CORPS›4920  CMP #$37›4930  BCC X79 Russian?›4940  LDA #$FF yes, mask orders and exit›4950  STA HITFLG›4960  BMI X75›4970 ;›4980 ;German unit›4990 ;set up orders display›5000 ;first calculate starting coords (BASEX, BASEY)›5010 ;›5020 X79 LDA #$01›5030  STA ORDCNT›5040  LDA #$00›5050  STA STPCNT›5060 ;›5070  LDA TXL›5080  AND #$07›5090  CLC›5100  ADC #$01›5110  CLC›5120  ADC SHPOS0›5130  STA BASEX›5140  STA STEPX›5150 ;›5160  LDA TYL›5170  AND #$0F›5180  LSR A›5190  SEC›5200  SBC #$01›5210  CLC›5220  ADC SCY›5230  STA BASEY›5240  STA STEPY›5250 ;›5260 ;now set up page 6 values›5270 ;›5280  LDX CORPS›5290  LDA HMORDS,X›5300  STA HOWMNY›5310  LDA WHORDS,X›5320  STA ORD1›5330  LDA WHORDH,X›5340  STA ORD2›5350 X75 JMP ENDISR›5360 ;›5370 ;ORDERS INPUT ROUTINE›5380 ;›5390 ORDERS LDA STKFLG›5400  BNE X75›5410  LDX CORPS›5420  CPX #$37›5430  BCC X64 Russian?›5440  LDX #$00 yes, error›5450  JMP SQUAWK›5460 X64 LDA HMORDS,X›5470  CMP #$08›5480  BCC X66 only 8 orders allowed›5490  LDX #$20›5500  JMP SQUAWK›5510 X66 LDA KRZFLG›5520  BNE X67 must wait for maltakreuze›5530  LDX #$40›5540  JMP SQUAWK›5550 X67 INC DBTIMR›5560  LDA DBTIMR wait for debounce time›5570  CMP #$10›5580  BCS X68›5590  BCC X75›5600 X68 LDA #$00›5610  STA DBTIMR reset debounce timer›5620  LDX STICK›5630  LDA STKTAB,X›5640  BPL X69›5650  LDX #$60 no diagonal orders allowed›5660  JMP SQUAWK›5670 ;›5680 ;OK, this is a good order›5690 ;›5700 X69 TAY›5710  STA STICKI›5720  LDA BEEPTB,Y›5730  STA AUDF1 "BEEP!"›5740  LDA #$A8›5750  STA AUDC1›5760  LDA #$FF›5770  STA STKFLG›5780 ;›5790  LDX CORPS›5800  INC HMORDS,X›5810  LDA HMORDS,X›5820  STA HOWMNY›5830  SEC›5840  SBC #$01›5850  AND #$03›5860  TAY›5870  STY TEMPI›5880  LDA HMORDS,X›5890  SEC›5900  SBC #$01›5910  LSR A›5920  LSR A›5930  TAX›5940  LDA STICKI›5950 ;isolate order›5960 X71 DEY›5970  BMI X70›5980  ASL A›5990  ASL A›6000  JMP X71›6010 X70 LDY TEMPI›6020  EOR ORD1,X fold in new order (sneaky code)›6030  AND MASKO,Y›6040  EOR ORD1,X›6050  STA ORD1,X›6060  LDA ORD1›6070  LDX CORPS›6080  STA WHORDS,X›6090  LDA ORD2›6100  STA WHORDH,X›6110 ;›6120 ;move maltakreuze›6130 ;›6140  JSR CLRP2›6150  LDX STICKI›6160  LDA KRZX›6170  CLC›6180  ADC XOFF,X›6190  STA KRZX›6200  LDA KRZY›6210  CLC›6220  ADC YOFF,X›6230  STA KRZY›6240 DSPKRZ LDA KRZX display it›6250  STA HPOSP2›6260  LDY KRZY›6270  LDX #$00›6280 LOOP26 LDA MLTKRZ,X›6290  CPY #$80›6300  BCS X45›6310  STA PLYR2,Y›6320 X45 INY›6330  INX›6340  CPX #$08›6350  BNE LOOP26›6360  BEQ EXITI›6370 ;›6380 ;ERROR on inputs routine›6390 ;squawks speaker and puts out error message›6400 ;›6410 SQUAWK LDY #$69›6420 LOOP28 LDA ERRMSG,X›6430  SEC›6440  SBC #$20›6450  STA TXTWDW,Y›6460  INY›6470  INX›6480  TXA›6490  AND #$1F›6500  BNE LOOP28›6510  LDA #$68›6520  STA AUDC1›6530  LDA #$50›6540  STA AUDF1 "HONK!"›6550  LDA #$FF›6560  STA ERRFLG›6570  BMI EXITI›6580 ;›6590 ;NO BUTTON PRESSED ROUTINE›6600 ;›6610 NOBUT STA DBTIMR›6620  LDA STICK›6630  AND #$0F›6640  EOR #$0F›6650  BNE SCROLL›6660  STA AUDC1›6670  STA STKFLG›6680  LDA #$08›6690  STA DELAY›6700  CLC›6710  ADC RTCLKL›6720  STA TIMSCL›6730  JSR ERRCLR›6740 EXITI JMP ENDISR›6750 SCROLL LDA #$00›6760  STA ATRACT›6770 ;›6780 ;acceleration feature of cursor›6790 ;›6800  LDA TIMSCL›6810  CMP RTCLKL›6820  BNE EXITI›6830  LDA DELAY›6840  CMP #$01›6850  BEQ X21›6860  SEC›6870  SBC #$01›6880  STA DELAY›6890 X21 CLC›6900  ADC RTCLKL›6910  STA TIMSCL›6920 ;›6930  LDA #$00›6940  STA OFFLO›6950  STA OFFHI zero the offset›6960 ;›6970  LDA STICK get joystick reading›6980  PHA save it on stack for other bit checks›6990  AND #$08 joystick left?›7000  BNE CHKRT no, move on›7010  LDA CURSXL›7020  BNE X13›7030  LDX CURSXH›7040  BEQ CHKUP›7050 X13 SEC›7060  SBC #$01›7070  STA CURSXL›7080  BCS X14›7090  DEC CURSXH›7100 X14 LDA SHPOS0›7110  CMP #$BA›7120  BEQ X1›7130  CLC›7140  ADC #$01›7150  STA SHPOS0›7160  STA HPOSP0›7170  BNE CHKUP›7180 X1 LDA XPOSL›7190  SEC decrement x-coordinate›7200  SBC #$01›7210  STA XPOSL›7220  AND #$07›7230  STA HSCROLL fine scroll›7240  CMP #$07 scroll overflow?›7250  BNE CHKUP no, move on›7260  INC OFFLO yes, mark it for offset›7270  CLV›7280  BVC CHKUP no point in checking for joystick right›7290 CHKRT PLA get back joystick byte›7300  PHA save it again›7310  AND #$04 joystick right?›7320  BNE CHKUP no, move on›7330  LDA CURSXL›7340  CMP #$64›7350  BNE X12›7360  LDX CURSXH›7370  BNE CHKUP›7380 X12 CLC›7390  ADC #$01›7400  STA CURSXL›7410  BCC X15›7420  INC CURSXH›7430 X15 LDA SHPOS0›7440  CMP #$36›7450  BEQ X2›7460  SEC›7470  SBC #$01›7480  STA SHPOS0›7490  STA HPOSP0›7500  BNE CHKUP›7510 X2 LDA XPOSL›7520  CLC no, increment x-coordinate›7530  ADC #$01›7540  STA XPOSL›7550 X4 AND #$07›7560  STA HSCROLL fine scroll›7570  BNE CHKUP scroll overflow? if not, move on›7580  DEC OFFLO yes, set up offset for character scroll›7590  DEC OFFHI›7600 CHKUP PLA joystick up?›7610  LSR A›7620  PHA›7630  BCS CHKDN no, ramble on›7640  LDA CURSYL›7650  CMP #$5E›7660  BNE X3›7670  LDX CURSYH›7680  CPX #$02›7690  BEQ CHKDN›7700 X3 INC CURSYL›7710  BNE X11›7720  INC CURSYH›7730 X11 LDX SCY›7740  CPX #$1B›7750  BEQ X6›7760  INC CURSYL›7770  BNE X18›7780  INC CURSYH›7790 X18 DEX›7800  STX SCY›7810  TXA›7820  CLC›7830  ADC #$12›7840  STA TEMPI›7850 LOOP4 LDA PLYR0,X›7860  STA PLYR0-1,X›7870  INX›7880  CPX TEMPI›7890  BNE LOOP4›7900  BEQ CHKDN›7910 X6 LDA YPOSL›7920  SEC›7930  SBC #$01›7940  BCS X7›7950  DEC YPOSH›7960 X7 STA YPOSL›7970  AND #$0F›7980  STA VSCROLL fine scroll›7990  CMP #$0F›8000  BNE CHKDN scroll overflow? If not, amble on›8010  LDA OFFLO yes, set up offset for character scroll›8020  SEC›8030  SBC #$30›8040  STA OFFLO›8050  LDA OFFHI›8060  SBC #$00›8070  STA OFFHI›8080 CHKDN PLA joystick down?›8090  LSR A›8100  BCS CHGDL no, trudge on›8110  LDA CURSYL›8120  CMP #$02›8130  BNE X5›8140  LDX CURSYH›8150  BEQ CHGDL›8160 X5 SEC›8170  SBC #$01›8180  STA CURSYL›8190  BCS X10›8200  DEC CURSYH›8210 X10 LDX SCY›8220  CPX #$4E›8230  BEQ X8›8240  SEC›8250  SBC #$01›8260  STA CURSYL›8270  BCS X19›8280  DEC CURSYH›8290 X19 INX›8300  STX SCY›8310  TXA›8320  CLC›8330  ADC #$12›8340  DEX›8350  DEX›8360  STX TEMPI›8370  TAX›8380 LOOP5 LDA PLYR0-1,X›8390  STA PLYR0,X›8400  DEX›8410  CPX TEMPI›8420  BNE LOOP5›8430  BEQ CHGDL›8440 X8 LDA YPOSL›8450  CLC no, decrement y-coordinate›8460  ADC #$01›8470  STA YPOSL›8480  BCC X9›8490  INC YPOSH›8500 X9 AND #$0F›8510  STA VSCROLL fine scroll›8520  BNE CHGDL no, move on›8530  LDA OFFLO yes, mark offset›8540  CLC›8550  ADC #$30›8560  STA OFFLO›8570  LDA OFFHI›8580  ADC #$00›8590  STA OFFHI›8600 ;›8610 ;In this loop we add the offset values to the existing›8620 ;LMS addresses of all display lines.›8630 ;This scrolls the characters.›8640 ;›8650 CHGDL LDY #$09›8660 DLOOP LDA (DLSTPT),Y›8670  CLC›8680  ADC OFFLO›8690  STA (DLSTPT),Y›8700  INY›8710  LDA (DLSTPT),Y›8720  ADC OFFHI›8730  STA (DLSTPT),Y›8740  INY›8750  INY›8760  CPY #$27›8770  BNE DLOOP›8780 ;›8790 ENDISR LDA YPOSH›8800  LSR A›8810  LDA YPOSL›8820  ROR A›8830  LSR A›8840  LSR A›8850  LSR A›8860  CMP #$11›8870  BCS X39›8880  LDA #$FF›8890  BMI X40›8900 X39 CMP #$1A›8910  BCC X41›8920  LDA #$02›8930  BPL X40›8940 X41 STA TEMPI›8950  INX›8960  LDA #$1D›8970  SEC›8980  SBC TEMPI›8990 X40 STA CNT1›9000  LDA #$00›9010  STA CNT2›9020  JMP XITVBV exit vertical blank routine›9030 ;›9040  *=$799C›9050 JSTP .BYTE 0,0,0,0,3,3,3,3›9060  .BYTE 2,2,2,2,1,1,1,0›9070  .BYTE 0,0,3,3,2,2,1,0›9080 DEFNC .BYTE 2,3,3,2,2,2,1,1,2,0›9090  *=$79C0›9100 ;›9110 ;SUBROUTINE DWORDS›9120 ;displays a single word from a long table of words›9130 ;›9140 DWORDS ASL A›9150  ASL A›9160  ASL A›9170  BCC ENTRY2›9180  TAX›9190 BOOP20 LDA WORDS+256,X›9200  SEC›9210  SBC #$20›9220  BEQ BNDW›9230  STA TXTWDW,Y›9240  INY›9250  INX›9260  TXA›9270  AND #$07›9280  BNE BOOP20›9290 BNDW INY›9300  RTS›9310 ENTRY2 TAX this is another entry point›9320 LOOP20 LDA WORDS,X›9330  SEC›9340  SBC #$20›9350  BEQ NDW›9360  STA TXTWDW,Y›9370  INY›9380  INX›9390  TXA›9400  AND #$07›9410  BNE LOOP20›9420 NDW INY›9430  RTS›9440 ;›9450 ;›9460 ;SUBROUTINE SWITCH FOR SWAPPING CORPS WITH TERRAIN›9470 ;›9480 SWITCH LDA #$00›9490  STA MAPHI›9500  LDA #$27›9510  SEC›9520  SBC CHUNKY›9530  ASL A›9540  ROL MAPHI›9550  ASL A›9560  ROL MAPHI›9570  ASL A›9580  ROL MAPHI›9590  ASL A›9600  ROL MAPHI›9610  STA TEMPLO›9620  LDX MAPHI›9630  STX TEMPHI›9640  ASL A›9650  ROL MAPHI›9660  CLC›9670  ADC TEMPLO›9680  STA MAPLO›9690  LDA MAPHI›9700  ADC TEMPHI›9710  ADC #$65›9720  STA MAPHI›9730  LDA #46›9740  SEC›9750  SBC CHUNKX›9760  TAY›9770  LDA (MAPLO),Y›9780  LDX CORPS›9790  BEQ X34›9800  PHA›9810  LDA SWAP,X›9820  STA (MAPLO),Y›9830  PLA›9840  STA SWAP,X›9850 X34 RTS›9860 ;›9870 ;SUBROUTINE CLRP1›9880 ;clears the arrow player›9890 ;›9900 CLRP1 LDA #$00›9910  LDY STEPY›9920  DEY›9930  TAX›9940 LOOP23 CPY #$80›9950  BCS X22›9960  STA PLYR1,Y›9970 X22 INY›9980  INX›9990  CPX #$0B›010000  BNE LOOP23›010010  RTS›010020 ;›010030 ;SUBROUTINE CLRP2›010040 ;clears the maltakreuze›010050 ;›010060 CLRP2 LDA #$00›010070  LDY KRZY›010080  TAX›010090 LOOP25 CPY #$80›010100  BCS X42›010110  STA PLYR2,Y›010120 X42 INY›010130  INX›010140  CPX #$0A›010150  BNE LOOP25›010160  RTS›010170 ;›010180 ;SUBROUTINE ERRCLR›010190 ;clears sound and the text window›010200 ;›010210 ERRCLR LDA ERRFLG›010220  BPL ENDERR›010230  LDA #$00›010240  STA ERRFLG›010250  LDY #$86›010260  LDX #$1F›010270 LOOP29 STA TXTWDW,Y›010280  DEY›010290  DEX›010300  BPL LOOP29›010310 ENDERR RTS›010320 ;›010330 BITTAB .BYTE $C0,3,$C,$30›010340 ROTARR .BYTE 4,9,14,19,24›010350  .BYTE 3,8,13,18,23›010360  .BYTE 2,7,12,17,22›010370  .BYTE 1,6,11,16,21›010380  .BYTE 0,5,10,15,20›010390 OBJX *=*+104›010400 ;›010410 ;From here to $7B00 is expansion RAM›010420 ;›010430 ;This is the DLI routine›010440 ;›010450  *=$7B00›010460 DLISRV PHA›010470  TXA›010480  PHA›010490  INC CNT2›010500  LDA CNT2›010510  CMP CNT1›010520  BNE OVER1›010530  LDX #$62 map DLI›010540  LDA #$28›010550  EOR COLRSH›010560  AND DRKMSK›010570  STA WSYNC›010580  STX CHBASE›010590  STA COLPF0›010600  JMP DLIOUT›010610 ;›010620 OVER1 CMP #$0F›010630  BNE OVER6›010640  LDA #$3A›010650  EOR COLRSH›010660  AND DRKMSK›010670  TAX›010680  LDA #$00›010690  EOR COLRSH›010700  AND DRKMSK›010710  STA WSYNC›010720  STX COLPF2›010730  STA COLPF1›010740  JMP DLIOUT›010750 ;›010760 OVER6 CMP #$01›010770  BNE OVER2›010780  LDA TRCOLR green tree color›010790  EOR COLRSH›010800  AND DRKMSK›010810  TAX›010820  LDA #$1A yellow band at top of map›010830  EOR COLRSH›010840  AND DRKMSK›010850  STA WSYNC›010860  STA COLBAK›010870  STX COLPF0›010880  LDA #$60›010890  STA CHBASE›010900  JMP DLIOUT›010910 ;›010920 OVER2 CMP #$03›010930  BNE OVER3›010940  LDA EARTH top of map›010950  EOR COLRSH›010960  AND DRKMSK›010970  STA WSYNC›010980  STA COLBAK›010990  JMP DLIOUT›011000 ;›011010 OVER3 CMP #$0D›011020  BNE OVER4›011030  LDX #$E0 bottom of map›011040  LDA #$22›011050  EOR COLRSH›011060  AND DRKMSK›011070  STA WSYNC›011080  STA COLPF2›011090  STX CHBASE›011100  JMP DLIOUT›011110 ;›011120 OVER4 CMP #$0E›011130  BNE OVER5›011140  LDA #$8A bright blue strip›011150  EOR COLRSH›011160  AND DRKMSK›011170  STA WSYNC›011180  STA COLBAK›011190  JMP DLIOUT›011200 ;›011210 OVER5 CMP #$10›011220  BNE DLIOUT›011230  LDA #$D4 green bottom›011240  EOR COLRSH›011250  AND DRKMSK›011260  PHA some extra delay›011270  PLA›011280  NOP›011290  STA COLBAK›011300 ;›011310 DLIOUT PLA›011320  TAX›011330  PLA›011340  RTI›011350 ;›011360 ;SUBROUTINE DNUMBR›011370 ;displays a number with leading zero suppress›011380 ;›011390 DNUMBR TAX›011400  CLC›011410  LDA HDIGIT,X›011420  BEQ X36›011430  ADC #$10›011440  STA TXTWDW,Y›011450  INY›011460  SEC›011470 X36 LDA TDIGIT,X›011480  BCS X38›011490  BEQ X37›011500 X38 CLC›011510  ADC #$10›011520  STA TXTWDW,Y›011530  INY›011540 X37 LDA ODIGIT,X›011550  CLC›011560  ADC #$10›011570  STA TXTWDW,Y›011580  INY›011590  RTS›011600 ;›011610 NDX .BYTE 0,1,2,3,4,9,14,19›011620  .BYTE 24,23,22,21,20,15,10,5›011630  .BYTE 6,7,8,13,18,17,16,11›011640 YINC .BYTE 1›011650 XINC .BYTE 0,$FF,0,1›011660 OFFNC .BYTE 1,1,1,1,1,1,2,2,1,0›011670  .END›