If you are still using the old URL (datacrystal.romhacking.net), please update your bookmarks! The old URL may stop working soon.
The current URL is datacrystal.tcrf.net.
The current URL is datacrystal.tcrf.net.
The Little Mermaid/ROM map: Difference between revisions
Jump to navigation
Jump to search
No edit summary |
No edit summary |
||
| Line 4: | Line 4: | ||
0x8000 | 0x8000 | ||
Runs the action scripts of every object slot | Runs the action scripts of every object slot from lowest to highest and checks for collisions each frame. | ||
06:8000:A5 B1 LDA $00B1 ; Check Ariel's health | 06:8000:A5 B1 LDA $00B1 ; Check Ariel's health | ||
06:8002:F0 3A BEQ $803E ; Exit if zero | 06:8002:F0 3A BEQ $803E ; Exit if zero | ||
| Line 38: | Line 38: | ||
06:803C:D0 CA BNE $8008 | 06:803C:D0 CA BNE $8008 | ||
06:803E:60 RTS ----------------------------------------- | 06:803E:60 RTS ----------------------------------------- | ||
Page 07 (0xC000-0xFFFF) | |||
Location in ROM: 0x1C010-0x2000F | |||
0xC250 | |||
Advance random number generator each frame | |||
07:C250:A2 00 LDX #$00 | |||
07:C252:A0 04 LDY #$04 | |||
07:C254:B5 E4 LDA $E4,X | |||
07:C256:29 02 AND #$02 | |||
07:C258:85 00 STA $0000 | |||
07:C25A:B5 E5 LDA $E5,X | |||
07:C25C:29 02 AND #$02 | |||
07:C25E:45 00 EOR $0000 ; If 0x02 bits of 0xE4 and 0xE5 | |||
07:C260:18 CLC ; are the same, highest bit of | |||
07:C261:F0 01 BEQ $C264 ; new RNG value will be zero. | |||
07:C263:38 SEC ; Otherwise, it will be one. | |||
07:C264:76 E4 ROR $E4,X ; Then shift all previous bits right. | |||
07:C266:E8 INX | |||
07:C267:88 DEY | |||
07:C268:D0 FA BNE $C264 | |||
07:C26A:60 RTS ----------------------------------------- | |||
Revision as of 22:15, 27 December 2018
Page 06 (0x8000-0xBFFF)
Address in ROM: 0x18010-0x1C00F
0x8000 Runs the action scripts of every object slot from lowest to highest and checks for collisions each frame. 06:8000:A5 B1 LDA $00B1 ; Check Ariel's health 06:8002:F0 3A BEQ $803E ; Exit if zero 06:8004:A2 01 LDX #$01 06:8006:86 EF STX $00EF ; Current slot # 06:8008:A9 06 LDA #$06 06:800A:85 99 STA $0099 ; ? 06:800C:BD 00 03 LDA $0300,X 06:800F:10 25 BPL $8036 ; Skip ahead if slot is empty 06:8011:BD A0 04 LDA $04A0,X ; Check if object is stunned 06:8014:D0 16 BNE $802C ; If so, skip action script 06:8016:BC 10 03 LDY $0310,X 06:8019:B9 20 85 LDA $8520,Y ; Obtain address of action script 06:801C:85 00 STA $0000 ; from jump table located 06:801E:B9 80 85 LDA $8580,Y ; at 0x8520,0x8580 06:8021:85 01 STA $0001 06:8023:A9 80 LDA #$80 ; Set return address 06:8025:48 PHA 06:8026:A9 2B LDA #$2B 06:8028:48 PHA 06:8029:6C 00 00 JMP ($0000) ; Run object's action script 06:802C:E0 03 CPX #$03 ; Check if object is a bubble 06:802E:90 06 BCC $8036 ; Jump ahead if so 06:8030:20 3F 80 JSR $803F ; Run action if object is colliding with Ariel 06:8033:20 FF 80 JSR $80FF ; Run action if object is colliding with a bubble 06:8036:E6 EF INC $00EF ; Tick up to next object slot 06:8038:A6 EF LDX $00EF 06:803A:E0 10 CPX #$10 ; Loop until all slots examined 06:803C:D0 CA BNE $8008 06:803E:60 RTS -----------------------------------------
Page 07 (0xC000-0xFFFF)
Location in ROM: 0x1C010-0x2000F
0xC250 Advance random number generator each frame 07:C250:A2 00 LDX #$00 07:C252:A0 04 LDY #$04 07:C254:B5 E4 LDA $E4,X 07:C256:29 02 AND #$02 07:C258:85 00 STA $0000 07:C25A:B5 E5 LDA $E5,X 07:C25C:29 02 AND #$02 07:C25E:45 00 EOR $0000 ; If 0x02 bits of 0xE4 and 0xE5 07:C260:18 CLC ; are the same, highest bit of 07:C261:F0 01 BEQ $C264 ; new RNG value will be zero. 07:C263:38 SEC ; Otherwise, it will be one. 07:C264:76 E4 ROR $E4,X ; Then shift all previous bits right. 07:C266:E8 INX 07:C267:88 DEY 07:C268:D0 FA BNE $C264 07:C26A:60 RTS -----------------------------------------