Popcorn Code
RAM Usage
Hardware Info
C000: 7E C3 76 JMP START ;
XYtoScreen:
; Convert screen X,Y coordinates to a memory pointer and a mask
; A=Y
; B=X
; Return X=pointer and B=mask
C003: 34 04 PSHS B ; Preserve B
C005: C6 20 LDB #$20 ; 32 bytes per screen row
C007: 3D MUL ; A * 32
C008: 8B 04 ADDA #$04 ; 0400 to D ... offset to screen
C00A: 1F 01 TFR D,X ; Return screen pointer in X
C00C: E6 E4 LDB ,S ; Get the X coordinate
C00E: 54 LSRB ; Divide by 4 ...
C00F: 54 LSRB ; ... (4 pixels per byte)
C010: 3A ABX ; Offset memory pointer
C011: E6 E0 LDB ,S+ ; Pop the X coordinate
C013: C4 03 ANDB #$03 ; Pixel number
C015: 10 8E C0 1C LDY #$C01C ; Look up ...
C019: E6 A5 LDB B,Y ; ... the bit pattern
C01B: 39 RTS ; Done
TwoBitMasks:
C01C: C0 ; 11000000
C01D: 30 ; 00110000
C01E: 0C ; 00001100
C01F: 03 ; 00000011
PrintChar:
; Print character in A to screen at X,Y = ($EA),($EB)
C020: 34 40 PSHS U ; Preserve U
C022: CE C5 B7 LDU #$C5B7 ; Alphanumeric graphics pictures
C025: C6 07 LDB #$07 ; 7 bytes each
C027: 3D MUL ; Offses to ...
C028: 33 CB LEAU D,U ; ... letter picture
C02A: DC EA LDD $EA ; Screen coordinates
C02C: 8D D5 BSR XYtoScreen ; Convert to screen pointer and mask
C02E: 86 07 LDA #$07 ; 7 rows (bytes) per character
C030: 97 FE STA $FE ; Row counter temporary
C032: A6 C0 LDA ,U+
C034: 34 16 PSHS X,B,A
C036: D7 FC STB $FC
C038: C6 06 LDB #$06
C03A: 96 FC LDA $FC
C03C: 43 COMA
C03D: A4 84 ANDA ,X
C03F: 64 E4 LSR ,S
C041: 24 08 BHS $C04B ;
C043: 34 02 PSHS A
C045: 96 FC LDA $FC
C047: 94 E9 ANDA $E9
C049: AA E0 ORA ,S+
C04B: A7 84 STA ,X
C04D: 04 FC LSR $FC
C04F: 04 FC LSR $FC
C051: 26 06 BNE $C059 ;
C053: 30 01 LEAX 1,X
C055: 86 C0 LDA #$C0
C057: 97 FC STA $FC
C059: 5A DECB
C05A: 26 DE BNE $C03A ;
C05C: 35 16 PULS A,B,X
C05E: 30 88 20 LEAX $20,X ; Next row
C061: 0A FE DEC $FE ; All 7 rows done?
C063: 26 CD BNE $C032 ; No ... go back for all
C065: 35 C0 PULS U,PC ; Restore U and out
C067: D6 DD LDB $DD
C069: 8E 03 64 LDX #$0364
C06C: AE 85 LDX B,X
C06E: CC AA 61 LDD #$AA61
C071: 20 03 BRA $C076 ;
C073: CC 55 21 LDD #$5521
C076: 97 E9 STA $E9
C078: D7 EB STB $EB
C07A: C6 58 LDB #$58
C07C: D7 EA STB $EA
C07E: 0F FD CLR $FD
C080: 34 10 PSHS X
C082: 35 02 PULS A
C084: 8D 02 BSR $C088 ;
C086: 35 02 PULS A
C088: 34 02 PSHS A
C08A: 44 LSRA
C08B: 44 LSRA
C08C: 44 LSRA
C08D: 44 LSRA
C08E: 8D 13 BSR $C0A3 ;
C090: 35 02 PULS A
C092: D6 EB LDB $EB
C094: CB 06 ADDB #$06
C096: D7 EB STB $EB
C098: 84 0F ANDA #$0F
C09A: 8D 07 BSR $C0A3 ;
C09C: D6 EB LDB $EB
C09E: CB 06 ADDB #$06
C0A0: D7 EB STB $EB
C0A2: 39 RTS
C0A3: 8B 1C ADDA #$1C
C0A5: 0D FD TST $FD
C0A7: 10 26 FF 75 LBNE PrintChar ; Print character
C0AB: 97 FD STA $FD
C0AD: 81 1C CMPA #$1C
C0AF: 10 26 FF 6D LBNE PrintChar ; Print character
C0B3: 86 1A LDA #$1A
C0B5: 0F FD CLR $FD
C0B7: 7E C0 20 JMP PrintChar ; Print character
C0BA: 0F DC CLR $DC
C0BC: 03 DC COM $DC
C0BE: 20 02 BRA $C0C2 ;
C0C0: 0F DC CLR $DC
C0C2: A6 80 LDA ,X+
C0C4: 84 7F ANDA #$7F
C0C6: 81 20 CMPA #$20
C0C8: 25 37 BCS $C101 ;
C0CA: 26 06 BNE $C0D2 ;
C0CC: 0D DC TST $DC
C0CE: 27 02 BEQ $C0D2 ;
C0D0: 03 E9 COM $E9
C0D2: 81 22 CMPA #$22
C0D4: 24 04 BHS $C0DA ;
C0D6: 80 06 SUBA #$06
C0D8: 20 12 BRA $C0EC ;
C0DA: 81 30 CMPA #$30
C0DC: 25 23 BCS $C101 ;
C0DE: 81 3A CMPA #$3A
C0E0: 24 04 BHS $C0E6 ;
C0E2: 80 14 SUBA #$14
C0E4: 20 06 BRA $C0EC ;
C0E6: 80 41 SUBA #$41
C0E8: 81 1A CMPA #$1A
C0EA: 24 15 BHS $C101 ;
C0EC: 34 10 PSHS X
C0EE: BD C0 20 JSR PrintChar ; Print character
C0F1: 35 10 PULS X
C0F3: 96 EB LDA $EB
C0F5: 8B 06 ADDA #$06
C0F7: 97 EB STA $EB
C0F9: 0D DC TST $DC
C0FB: 27 C5 BEQ $C0C2 ;
C0FD: 03 E9 COM $E9
C0FF: 20 C1 BRA $C0C2 ;
C101: 39 RTS
C102: 34 44 PSHS U,B
C104: 4C INCA
C105: C6 20 LDB #$20
C107: 3D MUL
C108: 8B 04 ADDA #$04
C10A: 1F 01 TFR D,X
C10C: E6 E0 LDB ,S+
C10E: 54 LSRB
C10F: 54 LSRB
C110: 3A ABX
C111: 10 8E C1 50 LDY #$C150
C115: 86 FF LDA #$FF
C117: 97 FD STA $FD
C119: 96 FF LDA $FF
C11B: CE C5 9B LDU #$C59B
C11E: C6 03 LDB #$03
C120: 3D MUL
C121: 33 C5 LEAU B,U
C123: 86 03 LDA #$03
C125: 97 FE STA $FE
C127: C6 02 LDB #$02
C129: A6 A0 LDA ,Y+
C12B: 43 COMA
C12C: A4 84 ANDA ,X
C12E: 0D FF TST $FF
C130: 27 0C BEQ $C13E ;
C132: A8 84 EORA ,X
C134: 27 02 BEQ $C138 ;
C136: 0F FD CLR $FD
C138: A6 3F LDA -1,Y
C13A: A4 C4 ANDA ,U
C13C: AA 84 ORA ,X
C13E: A7 80 STA ,X+
C140: 5A DECB
C141: 26 E6 BNE $C129 ;
C143: 30 88 1E LEAX $1E,X
C146: 33 41 LEAU 1,U
C148: 0A FE DEC $FE
C14A: 26 DB BNE $C127 ;
C14C: 03 FD COM $FD
C14E: 35 C0 PULS U,PC
C150: 0F C0 CLR $C0
C152: 3F SWI
C153: FC 03 F0 LDD $03F0
C156: A6 41 LDA 1,U
C158: 81 52 CMPA #$52
C15A: 24 5A BHS $C1B6 ;
C15C: 0F FF CLR $FF
C15E: EC 41 LDD 1,U
C160: 8D A0 BSR $C102 ;
C162: 6C 41 INC 1,U
C164: E6 43 LDB 3,U
C166: D7 FF STB $FF
C168: EC 41 LDD 1,U
C16A: 8D 96 BSR $C102 ;
C16C: 0D FD TST $FD
C16E: 27 45 BEQ $C1B5 ;
C170: A6 C4 LDA ,U
C172: 84 FE ANDA #$FE
C174: A7 C4 STA ,U
C176: BD C2 32 JSR $C232 ;
C179: 0F FF CLR $FF
C17B: EC 41 LDD 1,U
C17D: BD C1 02 JSR $C102 ;
C180: 0A FA DEC $FA
C182: DC E1 LDD $E1
C184: 10 83 0A F0 CMPD #$0AF0
C188: 24 0F BHS $C199 ;
C18A: D6 F1 LDB $F1
C18C: 58 LSLB
C18D: EB 43 ADDB 3,U
C18F: 86 C8 LDA #$C8
C191: 3D MUL
C192: 1F 89 TFR A,B
C194: 4F CLRA
C195: D3 E1 ADDD $E1
C197: DD E1 STD $E1
C199: 96 FB LDA $FB
C19B: 9A FA ORA $FA
C19D: 26 16 BNE $C1B5 ;
C19F: BD C2 F1 JSR $C2F1 ;
C1A2: 86 6E LDA #$6E
C1A4: 97 F6 STA $F6
C1A6: 96 E3 LDA $E3
C1A8: 4C INCA
C1A9: 81 08 CMPA #$08
C1AB: 24 02 BHS $C1AF ;
C1AD: 97 E3 STA $E3
C1AF: 0C F1 INC $F1
C1B1: 26 02 BNE $C1B5 ;
C1B3: 0A F1 DEC $F1
C1B5: 39 RTS
C1B6: 10 8E 03 00 LDY #$0300
C1BA: 0F FF CLR $FF
C1BC: C6 05 LDB #$05
C1BE: A6 A4 LDA ,Y
C1C0: 85 01 BITA #$01
C1C2: 27 0D BEQ $C1D1 ;
C1C4: 84 FE ANDA #$FE
C1C6: A7 A4 STA ,Y
C1C8: 34 24 PSHS Y,B
C1CA: EC 21 LDD 1,Y
C1CC: BD C1 02 JSR $C102 ;
C1CF: 35 24 PULS B,Y
C1D1: 31 24 LEAY 4,Y
C1D3: 5A DECB
C1D4: 26 E8 BNE $C1BE ;
C1D6: 0F FF CLR $FF
C1D8: 03 FF COM $FF
C1DA: BD C2 B6 JSR $C2B6 ;
C1DD: A6 43 LDA 3,U
C1DF: 97 FF STA $FF
C1E1: EC 41 LDD 1,U
C1E3: BD C1 02 JSR $C102 ;
C1E6: 86 80 LDA #$80
C1E8: A0 42 SUBA 2,U
C1EA: 97 F2 STA $F2
C1EC: 86 96 LDA #$96
C1EE: 97 FE STA $FE
C1F0: 86 02 LDA #$02
C1F2: B7 FF 20 STA PIA1_DA ;
C1F5: C6 05 LDB #$05
C1F7: 96 FE LDA $FE
C1F9: 4A DECA
C1FA: 12 NOP
C1FB: 12 NOP
C1FC: 26 FB BNE $C1F9 ;
C1FE: B6 FF 20 LDA PIA1_DA ;
C201: 88 FC EORA #$FC
C203: B7 FF 20 STA PIA1_DA ;
C206: 5A DECB
C207: 26 EE BNE $C1F7 ;
C209: D6 FE LDB $FE
C20B: 5C INCB
C20C: D7 FE STB $FE
C20E: C1 C8 CMPB #$C8
C210: 25 E3 BCS $C1F5 ;
C212: 0D F2 TST $F2
C214: 26 FC BNE $C212 ;
C216: DC E1 LDD $E1
C218: 10 83 02 58 CMPD #$0258
C21C: 25 04 BCS $C222 ;
C21E: 44 LSRA
C21F: 56 RORB
C220: DD E1 STD $E1
C222: 0A E3 DEC $E3
C224: 10 27 01 D6 LBEQ $C3FE ;
C228: 0F FA CLR $FA
C22A: BD C2 F1 JSR $C2F1 ;
C22D: 0F FA CLR $FA
C22F: 7E C4 9B JMP $C49B ;
C232: 86 02 LDA #$02
C234: B7 FF 20 STA PIA1_DA ;
C237: C6 50 LDB #$50
C239: 1F 98 TFR B,A
C23B: 4A DECA
C23C: 26 FD BNE $C23B ;
C23E: B6 FF 20 LDA PIA1_DA ;
C241: 88 E0 EORA #$E0
C243: B7 FF 20 STA PIA1_DA ;
C246: 5A DECB
C247: C1 14 CMPB #$14
C249: 24 EE BHS $C239 ;
C24B: A6 43 LDA 3,U
C24D: 9B F0 ADDA $F0
C24F: 19 DAA
C250: 97 F0 STA $F0
C252: 96 EF LDA $EF
C254: 89 00 ADCA #$00
C256: 19 DAA
C257: 97 EF STA $EF
C259: 9E EF LDX $EF
C25B: 7E C0 73 JMP $C073 ;
C25E: B6 FF 20 LDA PIA1_DA ;
C261: F6 FF 23 LDB PIA1_CB ;
C264: 34 46 PSHS U,B,A
C266: 17 E7 0B LBSR $A974
C269: 8E 01 5B LDX #$015B
C26C: 5F CLRB
C26D: 17 E7 75 LBSR $A9E5
C270: 35 46 PULS A,B,U
C272: B7 FF 20 STA PIA1_DA ;
C275: F7 FF 23 STB PIA1_CB ;
C278: B6 01 5A LDA $015A
C27B: 80 01 SUBA #$01
C27D: 24 02 BHS $C281 ;
C27F: 4F CLRA
C280: 39 RTS
C281: 81 3B CMPA #$3B
C283: 25 02 BCS $C287 ;
C285: 86 3A LDA #$3A
C287: 39 RTS
C288: BD A1 C1 JSR GETKEY ;
C28B: 81 03 CMPA #$03
C28D: 10 27 01 6D LBEQ $C3FE ;
C291: 81 20 CMPA #$20
C293: 26 0D BNE $C2A2 ;
C295: BD A1 C1 JSR GETKEY ;
C298: 81 03 CMPA #$03
C29A: 10 27 01 60 LBEQ $C3FE ;
C29E: 81 20 CMPA #$20
C2A0: 26 F3 BNE $C295 ;
C2A2: 8D BA BSR $C25E ;
C2A4: 91 E4 CMPA $E4
C2A6: 27 0A BEQ $C2B2 ;
C2A8: 34 02 PSHS A
C2AA: 0F FF CLR $FF
C2AC: 8D 08 BSR $C2B6 ;
C2AE: 35 02 PULS A
C2B0: 97 E4 STA $E4
C2B2: 0F FF CLR $FF
C2B4: 03 FF COM $FF
C2B6: D6 E4 LDB $E4
C2B8: 54 LSRB
C2B9: 8E 0E 20 LDX #$0E20
C2BC: 3A ABX
C2BD: 86 F0 LDA #$F0
C2BF: C6 01 LDB #$01
C2C1: D5 E4 BITB $E4
C2C3: 27 02 BEQ $C2C7 ;
C2C5: 86 0F LDA #$0F
C2C7: D6 E3 LDB $E3
C2C9: 34 16 PSHS X,B,A
C2CB: 97 FC STA $FC
C2CD: C6 06 LDB #$06
C2CF: 96 FC LDA $FC
C2D1: 43 COMA
C2D2: A4 84 ANDA ,X
C2D4: A7 E2 STA ,-S
C2D6: 96 FC LDA $FC
C2D8: 94 FF ANDA $FF
C2DA: AA E0 ORA ,S+
C2DC: A7 84 STA ,X
C2DE: 03 FC COM $FC
C2E0: 2A 02 BPL $C2E4 ;
C2E2: 30 01 LEAX 1,X
C2E4: 5A DECB
C2E5: 26 E8 BNE $C2CF ;
C2E7: 35 16 PULS A,B,X
C2E9: 30 89 FF 00 LEAX $FF00,X
C2ED: 5A DECB
C2EE: 26 D9 BNE $C2C9 ;
C2F0: 39 RTS
C2F1: 8D 3B BSR $C32E ;
C2F3: 8E 03 14 LDX #$0314
C2F6: 86 05 LDA #$05
C2F8: 97 FE STA $FE
C2FA: C6 50 LDB #$50
C2FC: D7 FB STB $FB
C2FE: 96 FE LDA $FE
C300: C6 10 LDB #$10
C302: A7 80 STA ,X+
C304: 5A DECB
C305: 26 FB BNE $C302 ;
C307: 0A FE DEC $FE
C309: 26 F3 BNE $C2FE ;
C30B: 4F CLRA
C30C: 8E 03 14 LDX #$0314
C30F: 34 02 PSHS A
C311: 5F CLRB
C312: A6 80 LDA ,X+
C314: 97 FF STA $FF
C316: A6 E4 LDA ,S
C318: 34 14 PSHS X,B
C31A: BD C1 02 JSR $C102 ;
C31D: 35 14 PULS B,X
C31F: CB 08 ADDB #$08
C321: C1 80 CMPB #$80
C323: 25 ED BCS $C312 ;
C325: A6 E0 LDA ,S+
C327: 8B 04 ADDA #$04
C329: 81 14 CMPA #$14
C32B: 25 E2 BCS $C30F ;
C32D: 39 RTS
C32E: 8E 05 80 LDX #$0580
C331: CE 0F 00 LDU #$0F00
C334: 4F CLRA
C335: 5F CLRB
C336: ED C3 STD ,--U
C338: 30 1F LEAX -1,X
C33A: 26 FA BNE $C336 ;
C33C: 39 RTS
C33D: 53
C33E: 43
C33F: 4F
C340: 52
C341: 45
C342: 00 48
C344: 49
C345: 47
C346: 48
C347: 00 4C
C349: 45
C34A: 56
C34B: 45
C34C: 4C
C34D: 20 00
C34F: 96 E9 LDA $E9
C351: D6 FE LDB $FE
C353: 34 06 PSHS B,A
C355: 86 FF LDA #$FF
C357: 97 E9 STA $E9
C359: 8E C3 48 LDX #$C348
C35C: CC 4E 4E LDD #$4E4E
C35F: DD EA STD $EA
C361: BD C0 C0 JSR $C0C0 ;
C364: 96 DD LDA $DD
C366: 44 LSRA
C367: 8B 1D ADDA #$1D
C369: BD C0 20 JSR PrintChar ; Print character
C36C: BD C0 67 JSR $C067 ;
C36F: 35 06 PULS A,B
C371: D7 FE STB $FE
C373: 97 E9 STA $E9
C375: 39 RTS
START:
C376: 10 CE 02 FE LDS #$02FE ; Initialize the stack
C37A: BD C6 D7 JSR RollTextScreen ; Show the credits with rolling border
C37D: 12 NOP
C37E: 1A 50 ORCC #$50 ; Turn interrupts off
C380: 8E C5 54 LDX #$C554 ; Replace interrupt vector ...
C383: BF 01 0D STX $010D ; ... with our own
C386: 86 E0 LDA #$E0
C388: 97 F3 STA $F3
C38A: 86 34 LDA #$34
C38C: B7 FF 01 STA PIA0_CA ;
C38F: B7 FF 21 STA PIA1_CA ;
C392: B7 FF 23 STA PIA1_CB ;
C395: 4C INCA
C396: B7 FF 03 STA PIA0_CB ;
C399: 8E C3 7D LDX #$C37D
C39C: 9F 72 STX $72
C39E: 86 55 LDA #$55
C3A0: 97 71 STA $71
C3A2: 1C EF ANDCC #$EF ; Turn interrupts back on
C3A4: 86 35 LDA #$35
C3A6: B7 FF 03 STA PIA0_CB ;
C3A9: 86 FF LDA #$FF
C3AB: B7 FF 22 STA PIA1_DB ;
C3AE: 8E 04 00 LDX #$0400 ; Top of screen
C3B1: 10 CE 02 FE LDS #$02FE ; Reset stack back to 02FE
C3B5: 6F 80 CLR ,X+ ; Clear 3K screen from ...
C3B7: 8C 10 00 CMPX #$1000 ; ... 4000 to 1000 ...
C3BA: 25 F9 BCS $C3B5 ; Do all of screen
C3BC: B7 FF C0 STA dispMode ;
C3BF: B7 FF C2 STA dispMode+2 ;
C3C2: B7 FF C5 STA dispMode+5 ;
C3C5: 8E C3 3D LDX #$C33D
C3C8: 86 58 LDA #$58
C3CA: 97 EA STA $EA
C3CC: 86 01 LDA #$01
C3CE: 97 EB STA $EB
C3D0: 86 55 LDA #$55
C3D2: 97 E9 STA $E9
C3D4: BD C0 C0 JSR $C0C0 ;
C3D7: CC AA 47 LDD #$AA47
C3DA: 97 E9 STA $E9
C3DC: D7 EB STB $EB
C3DE: 8E C3 43 LDX #$C343
C3E1: BD C0 C0 JSR $C0C0 ;
C3E4: 4F CLRA
C3E5: 5F CLRB
C3E6: DD EF STD $EF
C3E8: 8E 03 64 LDX #$0364
C3EB: C6 12 LDB #$12
C3ED: 6F 80 CLR ,X+
C3EF: 5A DECB
C3F0: 26 FB BNE $C3ED ;
C3F2: 0F DD CLR $DD
C3F4: BD C0 67 JSR $C067 ;
C3F7: 86 1C LDA #$1C ; The "0" in the character graphics
C3F9: BD C0 20 JSR PrintChar ; Print "0" character
C3FC: 0F DD CLR $DD
C3FE: 10 CE 02 FE LDS #$02FE
C402: D6 DD LDB $DD
C404: 8E 03 64 LDX #$0364
C407: 3A ABX
C408: DC EF LDD $EF
C40A: 10 A3 84 CMPD ,X
C40D: 25 02 BCS $C411 ;
C40F: ED 84 STD ,X
C411: BD C3 2E JSR $C32E ;
C414: BD C2 F1 JSR $C2F1 ;
C417: BD C3 4F JSR $C34F ;
C41A: 86 AA LDA #$AA
C41C: 97 E9 STA $E9
C41E: 86 0C LDA #$0C
C420: 97 FE STA $FE
C422: 0A FE DEC $FE
C424: 26 18 BNE $C43E ;
C426: 8E C5 AD LDX #$C5AD
C429: CC 23 24 LDD #$2324
C42C: DD EA STD $EA
C42E: 86 09 LDA #$09
C430: 34 02 PSHS A
C432: BD C0 BA JSR $C0BA ;
C435: 35 02 PULS A
C437: 03 E9 COM $E9
C439: 4A DECA
C43A: 26 F4 BNE $C430 ;
C43C: 20 E0 BRA $C41E ;
C43E: 17 DD 80 LBSR GETKEY ;
C441: 80 31 SUBA #$31
C443: 25 0A BCS $C44F ;
C445: 81 09 CMPA #$09
C447: 24 06 BHS $C44F ;
C449: 48 ASLA
C44A: 97 DD STA $DD
C44C: BD C3 4F JSR $C34F ;
C44F: 86 FF LDA #$FF
C451: B7 FF 02 STA PIA0_DB ;
C454: 13 SYNC
C455: B6 FF 00 LDA PIA0_DA ;
C458: 85 01 BITA #$01
C45A: 26 C6 BNE $C422 ;
C45C: BD C3 2E JSR $C32E ;
C45F: BD C2 F1 JSR $C2F1 ;
C462: 8E 00 00 LDX #$0000
C465: 9F EF STX $EF
C467: BD C0 73 JSR $C073 ;
C46A: 86 1C LDA #$1C ; The "0" character graphics
C46C: BD C0 20 JSR PrintChar ; Print "0"
C46F: BD C0 67 JSR $C067 ;
C472: 86 03 LDA #$03
C474: 97 EC STA $EC
C476: 86 20 LDA #$20
C478: 90 DD SUBA $DD
C47A: 97 F8 STA $F8
C47C: 86 20 LDA #$20
C47E: 97 E4 STA $E4
C480: 86 06 LDA #$06
C482: 97 E3 STA $E3
C484: CC 09 CF LDD #$09CF
C487: DD E5 STD $E5
C489: 96 DD LDA $DD
C48B: C6 32 LDB #$32
C48D: 3D MUL
C48E: C3 01 F4 ADDD #$01F4
C491: DD E1 STD $E1
C493: 0F DE CLR $DE
C495: 0C DE INC $DE
C497: 96 DD LDA $DD
C499: 97 F1 STA $F1
C49B: CE 03 00 LDU #$0300
C49E: 86 05 LDA #$05
C4A0: 6F C4 CLR ,U
C4A2: 33 44 LEAU 4,U
C4A4: 4A DECA
C4A5: 26 F9 BNE $C4A0 ;
C4A7: 10 CE 02 FE LDS #$02FE
C4AB: 86 6E LDA #$6E
C4AD: 97 F6 STA $F6
C4AF: 0F FA CLR $FA
C4B1: 86 64 LDA #$64
C4B3: 97 F5 STA $F5
C4B5: B6 FF 23 LDA PIA1_CB ;
C4B8: 8A 08 ORA #$08
C4BA: B7 FF 23 STA PIA1_CB ;
C4BD: 0A F5 DEC $F5
C4BF: 26 10 BNE $C4D1 ;
C4C1: 96 E8 LDA $E8
C4C3: 84 3F ANDA #$3F
C4C5: 8B B4 ADDA #$B4
C4C7: 97 F5 STA $F5
C4C9: 86 2E LDA #$2E
C4CB: B8 FF 20 EORA PIA1_DA ;
C4CE: B7 FF 20 STA PIA1_DA ;
C4D1: DC E7 LDD $E7
C4D3: D3 E5 ADDD $E5
C4D5: DD E7 STD $E7
C4D7: 24 03 BHS $C4DC ;
C4D9: BD C2 88 JSR $C288 ;
C4DC: DC DF LDD $DF
C4DE: D3 E1 ADDD $E1
C4E0: DD DF STD $DF
C4E2: 24 D9 BHS $C4BD ;
C4E4: CE 03 00 LDU #$0300
C4E7: C6 05 LDB #$05
C4E9: A6 C4 LDA ,U
C4EB: 85 01 BITA #$01
C4ED: 27 07 BEQ $C4F6 ;
C4EF: 34 04 PSHS B
C4F1: BD C1 56 JSR $C156 ;
C4F4: 35 04 PULS B
C4F6: 33 44 LEAU 4,U
C4F8: 5A DECB
C4F9: 26 EE BNE $C4E9 ;
C4FB: 0A F6 DEC $F6
C4FD: 26 BE BNE $C4BD ;
C4FF: 96 F8 LDA $F8
C501: 97 F6 STA $F6
C503: 96 FA LDA $FA
C505: 81 05 CMPA #$05
C507: 24 B4 BHS $C4BD ;
C509: 0D FB TST $FB
C50B: 27 B0 BEQ $C4BD ;
C50D: 10 8E 03 00 LDY #$0300
C511: C6 05 LDB #$05
C513: A6 A4 LDA ,Y
C515: 85 01 BITA #$01
C517: 27 07 BEQ $C520 ;
C519: 31 24 LEAY 4,Y
C51B: 5A DECB
C51C: 26 F5 BNE $C513 ;
C51E: 20 9D BRA $C4BD ;
C520: 8A 01 ORA #$01
C522: A7 A4 STA ,Y
C524: 96 FB LDA $FB
C526: 4A DECA
C527: 84 F0 ANDA #$F0
C529: 1F 89 TFR A,B
C52B: 96 FB LDA $FB
C52D: 4A DECA
C52E: 84 0F ANDA #$0F
C530: 94 E8 ANDA $E8
C532: 8E 03 14 LDX #$0314
C535: 3A ABX
C536: 54 LSRB
C537: 54 LSRB
C538: E7 21 STB 1,Y
C53A: C6 F8 LDB #$F8
C53C: CB 08 ADDB #$08
C53E: 6D 80 TST ,X+
C540: 27 FA BEQ $C53C ;
C542: 4A DECA
C543: 2A F7 BPL $C53C ;
C545: E7 22 STB 2,Y
C547: A6 1F LDA -1,X
C549: A7 23 STA 3,Y
C54B: 6F 1F CLR -1,X
C54D: 0A FB DEC $FB
C54F: 0C FA INC $FA
C551: 7E C4 BD JMP $C4BD ;
InterruptService:
C554: 96 F3 LDA $F3
C556: 1F 89 TFR A,B
C558: 56 RORB
C559: 46 RORA
C55A: 0D F2 TST $F2
C55C: 27 02 BEQ $C560 ;
C55E: 56 RORB
C55F: 46 RORA
C560: 97 F3 STA $F3
C562: C6 20 LDB #$20
C564: 8E 0E C0 LDX #$0EC0
C567: A7 80 STA ,X+
C569: 5A DECB
C56A: 26 FB BNE $C567 ;
C56C: 96 F2 LDA $F2
C56E: 27 24 BEQ $C594 ;
C570: 4A DECA
C571: 97 F2 STA $F2
C573: 86 03 LDA #$03
C575: 8E 0E 60 LDX #$0E60
C578: 34 02 PSHS A
C57A: 86 02 LDA #$02
C57C: C6 20 LDB #$20
C57E: 34 10 PSHS X
C580: 1C FE ANDCC #$FE
C582: 66 80 ROR ,X+
C584: 5A DECB
C585: 26 FB BNE $C582 ;
C587: 35 10 PULS X
C589: 4A DECA
C58A: 26 F0 BNE $C57C ;
C58C: 35 02 PULS A
C58E: 30 88 20 LEAX $20,X
C591: 4A DECA
C592: 26 E4 BNE $C578 ;
C594: B6 FF 02 LDA PIA0_DB ; Clear ...
C597: B6 FF 03 LDA PIA0_CB ; ... interrupt flags
C59A: 3B RTI ; Return from interrupt
C59B: 00 00 NEG $00
C59D: 00 FF NEG $FF
C59F: FF FF 55 STU $FF55
C5A2: 55 ; ????
C5A3: 55 ; ????
C5A4: 55 ; ????
C5A5: AA 55 ORA -11,U
C5A7: AA ; ????
C5A8: AA ; ????
C5A9: AA ; ????
C5AA: AA 55 ORA -11,U
C5AC: AA 47 ORA 7,U
C5AE: 41 ; ????
C5AF: 4D TSTA
C5B0: 45 ; ????
C5B1: 20 4F BRA $C602 ;
C5B3: 56 RORB
C5B4: 45 ; ????
C5B5: 52 ; ????
C5B6: 00
LetterGraphics:
; These are shown with bits flipped from left to right. The code
; flips them as it draws.
C5B7: 04 ; ..1..... ; A
C5B8: 0A ; .1.1....
C5B9: 11 ; 1...1...
C5BA: 11 ; 1...1...
C5BB: 1F ; 11111...
C5BC: 11 ; 1...1...
C5BD: 11 ; 1...1...
C5BE: 0F ; 1111.... ; B
C5BF: 12 ; .1..1...
C5C0: 12 ; .1..1...
C5C1: 0E ; .111....
C5C2: 12 ; .1..1...
C5C3: 12 ; .1..1...
C5C4: 0F ; 1111....
C5C5: 0E ; .111.... ; C
C5C6: 11 ; 1...1...
C5C7: 01 ; 1.......
C5C8: 01 ; 1.......
C5C9: 01 ; 1.......
C5CA: 11 ; 1...1...
C5CB: 0E ; .111....
C5CC: 0F ; 1111.... ; D
C5CD: 12 ; .1..1...
C5CE: 12 ; .1..1...
C5CF: 12 ; .1..1...
C5D0: 12 ; .1..1...
C5D1: 12 ; .1..1...
C5D2: 0F ; 1111....
C5D3: 1F ; 11111... ; E
C5D4: 01 ; 1.......
C5D5: 01 ; 1.......
C5D6: 0F ; 1111....
C5D7: 01 ; 1.......
C5D8: 01 ; 1.......
C5D9: 1F ; 11111...
C5DA: 1F ; 11111... ; F
C5DB: 01 ; 1.......
C5DC: 01 ; 1.......
C5DD: 07 ; 111.....
C5DE: 01 ; 1.......
C5DF: 01 ; 1.......
C5E0: 01 ; 1.......
C5E1: 0E ; .111.... ; G
C5E2: 11 ; 1...1...
C5E3: 01 ; 1.......
C5E4: 19 ; 1..11...
C5E5: 11 ; 1...1...
C5E6: 11 ; 1...1...
C5E7: 0E ; .111....
C5E8: 11 ; 1...1... ; H
C5E9: 11 ; 1...1...
C5EA: 11 ; 1...1...
C5EB: 1F ; 11111...
C5EC: 11 ; 1...1...
C5ED: 11 ; 1...1...
C5EE: 11 ; 1...1...
C5EF: 0E ; .111.... ; I
C5F0: 04 ; ..1.....
C5F1: 04 ; ..1.....
C5F2: 04 ; ..1.....
C5F3: 04 ; ..1.....
C5F4: 04 ; ..1.....
C5F5: 0E ; .111....
C5F6: 1C ; ..111... ; J
C5F7: 08 ; ...1....
C5F8: 08 ; ...1....
C5F9: 08 ; ...1....
C5FA: 09 ; 1..1....
C5FB: 09 ; 1..1....
C5FC: 06 ; .11.....
C5FD: 11 ; 1...1... ; K
C5FE: 09 ; 1..1....
C5FF: 05 ; 1.1.....
C600: 03 ; 11......
C601: 05 ; 1.1.....
C602: 09 ; 1..1....
C603: 11 ; 1...1...
C604: 01 ; 1....... ; L
C605: 01 ; 1.......
C606: 01 ; 1.......
C607: 01 ; 1.......
C608: 01 ; 1.......
C609: 01 ; 1.......
C60A: 1F ; 11111...
C60B: 11 ; 1...1... ; M
C60C: 1B ; 11.11...
C60D: 15 ; 1.1.1...
C60E: 15 ; 1.1.1...
C60F: 11 ; 1...1...
C610: 11 ; 1...1...
C611: 11 ; 1...1...
C612: 11 ; 1...1... ; N
C613: 13 ; 11..1...
C614: 15 ; 1.1.1...
C615: 19 ; 1..11...
C616: 11 ; 1...1...
C617: 11 ; 1...1...
C618: 11 ; 1...1...
C619: 0E ; .111.... ; O
C61A: 11 ; 1...1...
C61B: 11 ; 1...1...
C61C: 11 ; 1...1...
C61D: 11 ; 1...1...
C61E: 11 ; 1...1...
C61F: 0E ; .111....
C620: 0F ; 1111.... ; P
C621: 11 ; 1...1...
C622: 11 ; 1...1...
C623: 0F ; 1111....
C624: 01 ; 1.......
C625: 01 ; 1.......
C626: 01 ; 1.......
C627: 0E ; .111.... ; Q
C628: 11 ; 1...1...
C629: 11 ; 1...1...
C62A: 11 ; 1...1...
C62B: 15 ; 1.1.1...
C62C: 09 ; 1..1....
C62D: 16 ; .11.1...
C62E: 0F ; 1111.... ; R
C62F: 11 ; 1...1...
C630: 11 ; 1...1...
C631: 0F ; 1111....
C632: 05 ; 1.1.....
C633: 09 ; 1..1....
C634: 11 ; 1...1...
C635: 0E ; .111.... ; S
C636: 11 ; 1...1...
C637: 01 ; 1.......
C638: 0E ; .111....
C639: 10 ; ....1...
C63A: 11 ; 1...1...
C63B: 0E ; .111....
C63C: 1F ; 11111... ; T
C63D: 15 ; 1.1.1...
C63E: 04 ; ..1.....
C63F: 04 ; ..1.....
C640: 04 ; ..1.....
C641: 04 ; ..1.....
C642: 0E ; .111....
C643: 11 ; 1...1... ; U
C644: 11 ; 1...1...
C645: 11 ; 1...1...
C646: 11 ; 1...1...
C647: 11 ; 1...1...
C648: 11 ; 1...1...
C649: 0E ; .111....
C64A: 11 ; 1...1... ; V
C64B: 11 ; 1...1...
C64C: 11 ; 1...1...
C64D: 0A ; .1.1....
C64E: 0A ; .1.1....
C64F: 04 ; ..1.....
C650: 04 ; ..1.....
C651: 11 ; 1...1... ; W
C652: 11 ; 1...1...
C653: 11 ; 1...1...
C654: 11 ; 1...1...
C655: 15 ; 1.1.1...
C656: 15 ; 1.1.1...
C657: 0A ; .1.1....
C658: 11 ; 1...1... ; X
C659: 11 ; 1...1...
C65A: 0A ; .1.1....
C65B: 04 ; ..1.....
C65C: 0A ; .1.1....
C65D: 11 ; 1...1...
C65E: 11 ; 1...1...
C65F: 11 ; 1...1... ; Y
C660: 11 ; 1...1...
C661: 0A ; .1.1....
C662: 04 ; ..1.....
C663: 04 ; ..1.....
C664: 04 ; ..1.....
C665: 04 ; ..1.....
C666: 1F ; 11111... ; Z
C667: 11 ; 1...1...
C668: 08 ; ...1....
C669: 04 ; ..1.....
C66A: 02 ; .1......
C66B: 11 ; 1...1...
C66C: 1F ; 11111...
C66D: 00 ; ........ ; SPACE
C66E: 00 ; ........
C66F: 00 ; ........
C670: 00 ; ........
C671: 00 ; ........
C672: 00 ; ........
C673: 00 ; ........
C674: 04 ; ..1..... ; !
C675: 04 ; ..1.....
C676: 04 ; ..1.....
C677: 04 ; ..1.....
C678: 04 ; ..1.....
C679: 00 ; ........
C67A: 04 ; ..1.....
NumberGraphics:
; Drawn here reversed left to right as the the code does when
; rendering.
C67B: 0E ; .111.... ; 0
C67C: 11 ; 1...1...
C67D: 19 ; 1..11...
C67E: 15 ; 1.1.1...
C67F: 13 ; 11..1...
C680: 11 ; 1...1...
C681: 0E ; .111....
C682: 04 ; ..1..... ; 1
C683: 06 ; .11.....
C684: 04 ; ..1.....
C685: 04 ; ..1.....
C686: 04 ; ..1.....
C687: 04 ; ..1.....
C688: 0E ; .111....
C689: 0E ; .111.... ; 2
C68A: 11 ; 1...1...
C68B: 10 ; ....1...
C68C: 0E ; .111....
C68D: 01 ; 1.......
C68E: 01 ; 1.......
C68F: 1F ; 11111...
C690: 0E ; .111.... ; 3
C691: 11 ; 1...1...
C692: 10 ; ....1...
C693: 0C ; ..11....
C694: 10 ; ....1...
C695: 11 ; 1...1...
C696: 0E ; .111....
C697: 08 ; ...1.... ; 4
C698: 0C ; ..11....
C699: 0A ; .1.1....
C69A: 1F ; 11111...
C69B: 08 ; ...1....
C69C: 08 ; ...1....
C69D: 08 ; ...1....
C69E: 1F ; 11111... ; 5
C69F: 01 ; 1.......
C6A0: 01 ; 1.......
C6A1: 0F ; 1111....
C6A2: 10 ; ....1...
C6A3: 10 ; ....1...
C6A4: 0F ; 1111....
C6A5: 0C ; ..11.... ; 6
C6A6: 02 ; .1......
C6A7: 01 ; 1.......
C6A8: 0F ; 1111....
C6A9: 11 ; 1...1...
C6AA: 11 ; 1...1...
C6AB: 0E ; .111....
C6AC: 1F ; 11111... ; 7
C6AD: 10 ; ....1...
C6AE: 08 ; ...1....
C6AF: 04 ; ..1.....
C6B0: 02 ; .1......
C6B1: 01 ; 1.......
C6B2: 01 ; 1.......
C6B3: 0E ; .111.... ; 8
C6B4: 11 ; 1...1...
C6B5: 11 ; 1...1...
C6B6: 0E ; .111....
C6B7: 11 ; 1...1...
C6B8: 11 ; 1...1...
C6B9: 0E ; .111....
C6BA: 0E ; .111.... ; 9
C6BB: 11 ; 1...1...
C6BC: 11 ; 1...1...
C6BD: 1E ; .1111...
C6BE: 10 ; ....1...
C6BF: 08 ; ...1....
C6C0: 06 ; .11.....
PrintScreen:
C6C1: AE E1 LDX ,S++ ; Return address (data follows)
C6C3: A6 80 LDA ,X+ ; Get next character
C6C5: 27 05 BEQ $C6CC ; Printed all ... return to 1st past data
C6C7: 17 DC 40 LBSR PRINTCHAR ; Print the character
C6CA: 20 F7 BRA $C6C3 ; Do all the characters
C6CC: 6E 84 JMP ,X ; Return 1 past data terminator (C777)
RollBorder:
C6CE: 8B 10 ADDA #$10 ; Next color
C6D0: 8A 8F ORA #$8F ; Be sure it is a color block
C6D2: 81 8F CMPA #$8F ; Blank color?
C6D4: 27 F8 BEQ RollBorder ; Yes ... skip that one
C6D6: 39 RTS ; Return new color in A
; Text screen with rolling border. Return when a key is pressed or the wait
; time has passed (allows the game demo).
RollTextScreen:
C6D7: 86 39 LDA #$39 ; ??
C6D9: B7 01 67 STA $0167 ; ??
C6DC: 17 E2 49 LBSR CLRSCREEN ; Clear the screen
C6DF: 86 0D LDA #$0D ; 0000_1101 Alphanumeric graphics with ...
C6E1: B7 FF 22 STA PIA1_DB ; ... pink background ???
C6E4: BD C6 C1 JSR PrintScreen ; Print the text and return to C777
;
; "<cr>"
; "<cr>"
; "<cr>"
; " POPCORN<cr>"
; "<cr>"
; " BY<cr>"
; " STEVE BJORK<cr>"
; "<cr>"
; " COPYRIGHT (C) 1981<cr>"
; " DATASOFT INC.<cr>"
; "<cr>"
; "<cr>"
; " LICENSED TO TANDY CORP.<cr>"
; ""
; ""
; ""
;
C6E7: 0D 0D 0D 20 20 20 20 20 20 20 20 20
C6F3: 20 20 20 50 4F 50 43 4F 52 4E 0D 0D
C6FF: 20 20 20 20 20 20 20 20 20 20 20 20
C70B: 20 20 20 42 59 0D 20 20 20 20 20 20
C717: 20 20 20 20 53 54 45 56 45 20 42 4A
C723: 4F 52 4B 0D 0D 20 20 20 20 20 20 43
C72F: 4F 50 59 52 49 47 48 54 20 28 43 29
C73B: 20 31 39 38 31 0D 20 20 20 20 20 20
C747: 20 20 20 44 41 54 41 53 4F 46 54 20
C753: 49 4E 43 2E 0D 0D 0D 20 20 20 20 20
C75F: 4C 49 43 45 4E 53 45 44 20 54 4F 20
C76B: 54 41 4E 44 59 20 43 4F 52 50 2E 00
C777: CC 9F 10 LDD #$9F10 ; Screen value 9F and 16 double blocks
C77A: 8E 04 00 LDX #$0400 ; Start of screen
C77D: A7 80 STA ,X+ ; Double color block ...
C77F: A7 80 STA ,X+ ; ... along top
C781: BD C6 CE JSR RollBorder ; Change color
C784: 5A DECB ; All done across top?
C785: 26 F6 BNE $C77D ; No ... go back for all
C787: C6 0E LDB #$0E ; 14 rows down the right side
C789: 30 88 1F LEAX $1F,X ; One block down from upper right corner
C78C: A7 00 STA 0,X ; Double color block ...
C78E: A7 1F STA -1,X ; ... along right of screen
C790: 30 88 20 LEAX $20,X ; Next row down
C793: BD C6 CE JSR RollBorder ; Change color
C796: 5A DECB ; All done down right side?
C797: 26 F3 BNE $C78C ; No ... go back for all
C799: C6 10 LDB #$10 ; 16 double blocks along bottom
C79B: A7 84 STA ,X ; Double color block ...
C79D: A7 1F STA -1,X ; ... along bottom
C79F: 30 1E LEAX -2,X ; Back up one block along bottom
C7A1: BD C6 CE JSR RollBorder ; Change color
C7A4: 5A DECB ; All done across bottom?
C7A5: 26 F4 BNE $C79B ; No ... go back for all
C7A7: 30 88 E1 LEAX $E1,X ; One block up from lower right corner
C7AA: C6 0E LDB #$0E ; 14 rows up left side
C7AC: A7 84 STA ,X ; Double color block ...
C7AE: A7 01 STA 1,X ; ... along left side
C7B0: 30 88 E0 LEAX $E0,X ; One row up
C7B3: BD C6 CE JSR RollBorder ; Change color
C7B6: 5A DECB ; All done up the left side?
C7B7: 26 F3 BNE $C7AC ; No ... go back for all
C7B9: 5F CLRB ; 256 passes through rolling border before game demo
C7BA: 86 09 LDA #$09 ; Wait 9 60Hz interrupts
C7BC: 7D FF 03 TST PIA0_CB ; Vertical retrace?
C7BF: 2A FB BPL $C7BC ; No ... wait for it
C7C1: 7D FF 02 TST PIA0_DB ; Clear the interrupt bit
C7C4: 4A DECA ; All waits done?
C7C5: 26 F5 BNE $C7BC ; No ... go back for all
C7C7: 8E 04 00 LDX #$0400 ; Top of screen
C7CA: A6 80 LDA ,X+ ; Next character
C7CC: 2A 0A BPL $C7D8 ; Skip it if it is not a graphics block
C7CE: 80 10 SUBA #$10 ; Change ...
C7D0: 8A 8F ORA #$8F ; ... the color
C7D2: 81 8F CMPA #$8F ; Skip the empty ...
C7D4: 27 F8 BEQ $C7CE ; ... color block
C7D6: A7 1F STA -1,X ; Replace the old block with a new
C7D8: 8C 06 00 CMPX #$0600 ; The entire screen done?
C7DB: 26 ED BNE $C7CA ; No ... go back for the whole screen
C7DD: 17 D9 E1 LBSR GETKEY ; Is a key ...
C7E0: 84 7F ANDA #$7F ; ... pressed?
C7E2: 26 03 BNE $C7E7 ; Yes ... exit
C7E4: 5A DECB ; All loops of "roll border" done?
C7E5: 26 D3 BNE $C7BA ; No ... go back for all
C7E7: 39 RTS ; Done with text screen and rolling border
; Just a note in the code -- never used by the game.
; "__HI_FROM_STEVE___"
C7E8: 20 20 48 49 20 46 52 4F 4D 20 53 54 45 56 45 20
C7F8: 20 20 00 00 00 00 00 00
