Random notes

These are some random notes I made a while ago. Dunno whether they're useful to anyone or not. They're not at all guaranteed to be correct - a lot of it is untested assumption, so you may have to confirm it if you wanna use any of it. It's mainly just skeletal work I suppose. This is for Sonic 2 by the way.

Collision Response Research.

Code (Text):

1. COLLISION RESPONSES
2. ===================
3.  
4. Bitfield:
5. 0000 0000
6. TTSS SSSS
7.  
8. TT is definately correct.
9. SS SSSS is questionable. It is the size, but the format I am unsure of. Look at the following data:
10.  
11. 0100 0111: Collision Event, 16x16 (ring)
12. 0100 0110: Collision Event, 32x32 (monitor)
13. 1101 1000: Starpost (o_O)
14. 0000 1010: Octopus Badnik OOZ, Seahorse Badnik, Buzz Bomber Badnik (16x32)
15. 0000 1001: Fish from EHZ (16x16)
16. 0000 1001: Coconuts EHZ (16x16)
17. 0000 1111: EHZ Boss (64x64)
18.  
19. S: SIZE
20. T: 00: Enemy, 01: Collision Event, 10: Hurt, 11: Nothing?? (it is used by the starpost though)
21.  
22. 00: No collision
23. 01: Enemy
24. 08: Very Small Enemy
25. 0F: Large Enemy
26. 10: Large Enemy
27. 14: Very Wide Enemy
28. 18: Very Small Enemy (8x8?)
29. 1C: Very Small Enemy (8x8?)
30. 20: Tall Enemy
31. 24: Wide Enemy
32. 28: Very Small Enemy
33. 2C: Tall Enemy
34. 30: Very Small Enemy
35. 3F: Huge Enemy (256x256? o_O)
36. 40: Collision Event - Small (And destroy)
37. 7F: Huge Collision Event (256x256?)
38. 80: Hurt, Can't destroy, small
39. C0: Nothing
40. FF: Nothing (256x256 maybe;P)

Mappings stuff. I've since learned that Hivebrain has a guide on Sonicology.

Code (Text):

1. MAPPINGS: SPRITE SIZES
2. ======================
3.  
4. 00: 8x8
5. 01: 8x16
6. 02: 8x24
7. 03: 8x32
8. 04: 16x8
9. 05: 16x16
10. 06: 16x24
11. 07: 16x32
12. 08: 24x8
13. 09: 24x16
14. 0A: 24x24
15. 0B: 24x32
16. 0C: 32x8
17. 0D: 32x16
18. 0E: 32x24
19. 0F: 32x32
20.  
21. FLAGS
22. =====
23.  
24. Add to Vram:
25.  
26. + $0800: Horizontal Flip
27. + $1000: Vertical Flip
28. + $2000: Use Default Palette Line +1
29. + $4000: Use Default Palette Line +2
30. + $6000: Use Default Palette Line +3
31. + $8000: Always in Foreground
32.  
33. To get the right address in VRAM, multiply the block number by $20 (32)

Some very primitive object documentation. These must've been random scribblings.

Code (Text):

1. OBJECTS - ROUTINE 0: INIT
2. ROUTINE 1: BEFORE COLLISION FRAME EVENT
3. ROUTINE 2: COLLISION EVENT
4. ROUTINE X: CUSTOM EVENT
5.  
6. loc_164E6: Clear an Object's SST entries (destroy the object)
7. 164F4: Draw the object
8. 16544: animation script

This is to do with Sonic's animation frames.

Code (Text):

1. Sonic 3 SST
2.  
3. $16 - To do with gravity
4. $14 - Y Location
5. $1A - Y speed
6. $1C - X speed
7. $18 - X speed
8. $10 - X location
9. $04 - Direction?
10. $1E - Jumping/Rolling
11.  
12. $22 - FRAME NUMBER TO DISPLAY
13.  
14. SONIC 3
15.  
16. $1-8, walking
17. $9-$20 - walking (various angles)
18. $6A-77 - running in tree trunk (twirl-run)
19. $B1-B3 - end of level pose
20. $9D-9F - skidding
21. $BA - standing
22. $BE/BD - waiting
23. $AD/AE/AF - parts of sonic bored
24. $D9 - last frame of sonic bored
25. $21-24 - running
26. $C3/C4 - looking up
27. $9B/9C - looking down
28. $96-9A - rolling
29. $86-8B - charging spindash
30. $B6-B9 - pushing
31. $32-3B - sonic twirling
32. $8D - Sonic hurt
33. $90-91 - Sonic hanging on
34. $79-7F - Sonic hanging on (various angles)
35.  
36. SONIC 2
37.  
38. $1 - standing ? ?X
39. $2-3 start bored animation ?X
40. $4-5 tappings foot (bored) ?X
41. $6 - look at watch ?    X
42. $7 - start lie down ?   X
43. $8-9 lying down ? ?X
44. $A - start lying down ? X
45. $0B/0C - looking up ?   X
46. $0D-0F (second half of walking) ?X
47. $10-14 (first half of walking) ?X
48. $15-2C walking - angled ?   X
49. $2D-30 - sonic running ?    X
50. $31-3C - running angled ?  
51. $3D-41 - rolling ?  X
52. $42-47 - charging spindash ?X
53. $48-4B - pushing ?  X
54. $4C/4D - looking down ? X
55. $4E/4F - hurt ? ?X
56. $50/51 - holding on (horizontal)
57. $52/53 - holding on, vertical
58. $54-59 - spinning in air (above fan)    X (twirling)
59. $5A - breathe in air
60. $5B - standing spring frame ?X (twirling)
61. $5C - dead
62. $5D - drowned
63. $5E - dead (grey? o_O)
64. $5F-6A - twirling from spring ?X (twirling)
65. $6B/6C - hanging (used in WFZ for the metal bars you hang onto) X
66. $6D-6F - Super Sonic Transformation
67. $75-78 - Super Sonic Walk
68. $D2-D5 - skidding ? X
69. Balancing?

VRAM blocks for the letters on the title screen...

Code (Text):

1. TITLE SCREEN LETTERS
2. 68E A
3. 68F B
4. 690 C ? 69C O
5. 691 D ? 69D P
6. 692 E ? 69E Q
7. 693 F ? 69F R
8. 694 G ? 6A0 S
9. 695 H ? 6A1 T
10. 696 I ? 6A2 U
11. 697 J ? 6A3 V
12. 698 K ? 6A4 W
13. 699 L ? 6A5 Y
14. 69A M ? 6A6 Y
15. 69B N ? 6A7 Z

That's all I found in that folder. I thought it best to post it in case anyone has any use of it. *shrugs*

EDIT: Oops. Found some more.

Code (Text):

1. LEVEL SELECT:
2. 0000 - SPACE    001C - :    0029 - L    0036 - Y
3. 0010 - 0    001D - .    002A - M    0037 - Z
4. 0011 - 1    001E - A    002B - N
5. 0012 - 2    001F - B    002C - O
6. 0013 - 3    0020 - C    002D - P
7. 0014 - 4    0021 - D    002E - Q
8. 0015 - 5    0022 - E    002F - R
9. 0016 - 6    0023 - F    0030 - S
10. 0017 - 7    0024 - G    0031 - T
11. 0018 - 8    0025 - H    0032 - U
12. 0019 - 9 ?0026 - I  0033 - V
13. 001A - *    0027 - J    0034 - W
14. 001B - ?    0028 - K    0035 - X

Random disassembly. It's the title screen.

Code (Text):

1.  ?lea   ($FFFFFB00).w,a1 ?;Move Address of Palette data into a1
2.  ?moveq #0,d0 ? ?;init d0
3.  ?move.w    #$3F,d1 ? ?;Move ($3F - 63) into d1
4.  
5. loc_3B8A: ?; CODE XREF: ROM:00003B8Cj
6.  ?move.l    d0,(a1)+ ? ?;Moves d0 to value at address a1 and increments a1 (clears a palette colour then moves to the next)
7.  ?dbf   d1,loc_3B8A ? ?;Loops back to loc_3B8A until it has been done d1 (63) times.
8.  ?moveq #1,d0 ? ?;move 1 into d0
9.  ?bsr.w sub_2712 ? ?;Branch
10.  ?move.b    #0,($FFFFFFFA).w ?;Set Debug mode to 0
11.  ?move.w    #0,($FFFFFFD8).w ?;2 Player mode to 0
12.  ?move.w    #$280,($FFFFF614).w ?;Moves $280 into F614, making the number of frames to wait for demo guide to $280 frames
13.  ?clr.w ($FFFFF604).w ?;Clear 1 Player buttons being pressed
14.  ?move.b    #$E,($FFFFB040).w ?;Putting Flashing stars into SST as instance 2  
15.  ?move.b    #2,($FFFFB068).w ?;Sets object subtype 2 for creating stars.
16.  ?jsr   sub_15F9C ? ?;jump to subroutine
17.  ?jsr   sub_16604 ? ?;jump to subroutine
18.  ?moveq #0,d0 ? ?;init d0
19.  ?bsr.w sub_1650 ? ?;
20.  ?move.w    #0,($FFFFFFD4).w ?;Initilisation Cheat counter for cheats involving title screen
21.  ?move.w    #0,($FFFFFFD6).w ?;Initilisation Cheat counter for cheats involving title screen
22.  ?nop  
23.  ?nop  
24.  ?nop  
25.  ?nop  
26.  ?nop  
27.  ?nop  
28.  ?move.w    #4,($FFFFEED2).w ?;Controls how close sonic can get to the edge of the screen, before the camera moves. ?
29.  ?move.w    #0,($FFFFE500).w ?;
30.  ?lea   ($FFFFFF20).w,a1 ?;
31.  ?moveq #$B,d0
32.  
33. loc_3BF4: ?; CODE XREF: ROM:00003BF8j
34.  ?move.w    #-1,(a1)+
35.  ?dbf   d0,loc_3BF4
36.  ?move.w    #-$280,($FFFFEE00).w;Set the camera position X
37.  ?move.w    ($FFFFF60C).w,d0   
38.  ?ori.b #$40,d0; ?;Or on 40 and d0 (F60C)
39.  ?move.w    d0,($C00004).l ?;move the value in d0 into the VDP register
40.  ?bsr.w sub_23C6 ? ?
41.  
42. loc_3C14: ?; CODE XREF: ROM:00003C5Cj
43.  ? ?; ROM:00003C6Cj
44.  ?move.b    #4,($FFFFF62A).w
45.  ?bsr.w sub_3384
46.  ?jsr   sub_15F9C ?
47.  ?bsr.w sub_3E98 ?;branch to unknown subroutine
48.  ?jsr   sub_16604 ? ?;jump to unknown subroutine
49.  ?lea   ($FFFFF804).w,a1 ?;Set a1 to point to FF804 ("PLC" for Sonic and Tails in the Title Screen)
50.  ?moveq #0,d0 ? ?;Init d0
51.  ?moveq #$4F,d6 ? ?;move 4F (79) into d6 to prepare for loop
52.  
53. loc_3C36: ?; CODE XREF: ROM:00003C44j
54.  ?tst.w (a1) ? ?;Test if a1 is 0
55.  ?bne.s loc_3C42 ?;branch if ?not 0
56.  ?bchg  #2,d0 ? ?;Set Sonic and Tails Sprite Priority to 2, to stop them appearing in front of the banner
57.  ?move.w    d0,2(a1) ?;Inserts Value into Ram Address
58.  
59. loc_3C42: ?; CODE XREF: ROM:00003C38j
60.  ?addq.w    #8,a1 ? ?;Add 8 to a1
61.  ?dbf   d6,loc_3C36 ? ?;Loops until done 4F(79)times
62.  ?bsr.w sub_168A ? ?;Unknown Subroutine
63.  ?bsr.w sub_3DB4 ? ?;check for miles cheat buttons
64.  ?tst.w ($FFFFF614).w ?;Tests for demo time
65.  ?beq.w loc_3D2E ? ?;If 0, start demo mode
66.  ?tst.b ($FFFFB06F).w ? ? ? ? ? ? ?;Test player input
67.  ?beq.w loc_3C14 ? ? ? ? ? ? ? ? ?;If not branch to Unknown Location
68.  ?move.b    ($FFFFF605).w,d0 ?;put the buttons being held down into d0
69.  ?or.b  ($FFFFF607).w,d0 ?;OR it with the 2 player buttons - so both controllers work
70.  ?andi.b    #-$80,d0 ? ? ? ? ? ? ? ? ?;AND d0 with -$80: we're only testing for the start button
71.  ?beq.w loc_3C14 ? ?;if the start button isn't pressed, loop back and carry on
72.  ?move.b    #$C,($FFFFF600).w ?;go into normal game mode at the end of the frame (the stuff below will take precedence)
73.  ?move.b    #3,($FFFFFE12).w ?;set the starting lives to 3
74.  
75. loc_3C7C:
76.  ?move.b    #3,($FFFFFEC6).w ? ? ? ? ?;Set starting tails lives to 3
77.  ?moveq #0,d0 ? ?;initilisation of variables to 0 for level start.
78.  ?move.w    d0,($FFFFFE20).w ?;rings init
79.  ?move.l    d0,($FFFFFE22).w ?;time counter init
80.  ?move.l    d0,($FFFFFE26).w ?;score init
81.  ?move.w    d0,($FFFFFED0).w ?;Tails ring counter (2 player mode, only for results screen)
82.  ?move.l    d0,($FFFFFED2).w ?;Tails Time counter (2 player mode, only for results screen)
83.  ?move.l    d0,($FFFFFED6).w ?;Tails Score Counter (2 Player mode, only for results screen)
84.  ?move.b    d0,($FFFFFE18).w ?;continues
85.  ?move.l    #$1388,($FFFFFFC0).w;set the score needed for a life for Sonic to 5000 (50000 in game)
86.  ?move.l    #$1388,($FFFFFFC4).w;set the score needed for a life for Tails to 5000 (50000 in game)
87.  ?move.b    #-7,d0 ? ?;set d0 to $79
88.  ?bsr.w sub_1370 ? ?;play the sound in d0 ($79) - stops music
89.  ?moveq #0,d0 ? ?;init d0
90.  ?move.b    ($FFFFFF86).w,d0 ?;move the title screen selection into d0
91.  ?bne.s loc_3CF6 ? ?;go to options if the selection is not 0
92.  ?moveq #0,d0 ? ?;set d0 to 0 for more variable initialisation
93.  ?move.w    d0,($FFFFFF8A).w ?;set $FF8A (unknown) to 0
94.  ?move.w    d0,($FFFFFFD8).w ?;set $FFD8 (2 player mode) to 0
95.  ?move.w    d0,($FFFFFE10).w ?;set the zone to 0
96.  ?tst.b ($FFFFFFD0).w ?;check to see if level select is active
97.  ?beq.s loc_3CE4 ? ?;if it isn't active, skip
98.  ?btst  #6,($FFFFF604).w ?;check button A
99.  ?beq.s loc_3CE4 ? ?;if it is not pressed, skip
100.  ?move.b    #$28,($FFFFF600).w ?;go to the level select instead of normal game
101.  ?rts ? ? ? ?;exit
102. ; ???????????????????????????????????????????????????????????????????????????
103.  
104. loc_3CE4: ?; CODE XREF: ROM:00003CD2j ? set up some variables
105.  ? ?; ROM:00003CDAj
106.  ?move.w    d0,($FFFFFE16).w;Special Stage Counter ?   
107.  ?move.w    d0,($FFFFFFB0).w;number of emeralds to 0
108.  ?move.l    d0,($FFFFFFB2).w;Number of emeralds to draw to 0
109.  ?move.l    d0,($FFFFFFB6).w;Number of emeralds to draw to 0
110.  ?rts  
111. ; ???????????????????????????????????????????????????????????????????????????
112.  
113. loc_3CF6: ?; CODE XREF: ROM:00003CBEj ?(2 player level select)
114.  ?subq.b    #1,d0 ?;subtract 1 from d0 - if it was 1, it will now be 0. If it was 2, it will now be 1
115.  ?bne.s loc_3D20 ?;if the result is not 0 (if d0 was previously not 1) go to the options menu instead. If d0 was 1 it would now be 0
116.  ?moveq #1,d1 ?;set d1 to 1
117.  ?move.w    d1,($FFFFFF8A).w;set $FF8A (some kind of selection option) to 1 (d1)   
118.  ?move.w    d1,($FFFFFFD8).w;set $FFD8 (2 player mode) to 1 (d1)
119.  ?moveq #0,d0 ? ?
120.  ?move.w    d0,($FFFFFFB0).w;number of emeralds to 0
121.  ?move.l    d0,($FFFFFFB2).w;Number of emeralds to draw to 0
122.  ?move.l    d0,($FFFFFFB6).w;Number of emeralds to draw to 0
123.  ?move.b    #$1C,($FFFFF600).w ?;go to 2 player level select screen
124.  ?move.b    #0,($FFFFFF88).w ?;Selection on 2 player level select menu ?   
125.  ?rts  
126. ; ???????????????????????????????????????????????????????????????????????????
127.  
128. loc_3D20: ? ? ? ? ?;Options menu code
129.  ?move.b    #$24,($FFFFF600).w;Go to options menu
130.  ?move.b    #0,($FFFFFF8C).w ?;Box selected in options menu
131.  ?rts  
132. ; ???????????????????????????????????????????????????????????????????????????
133.  
134. loc_3D2E: ?; CODE XREF: ROM:00003C54j
135.  ?move.b    #-7,d0 ? ?;Load sound into d0 (stop music sound)
136.  ?bsr.w sub_1370 ? ?;Play sound in d0   (Stops music)
137.  ?move.w    ($FFFFFFF2).w,d0 ?;Move value in FFF2 (Demo level) into d0
138.  ?andi.w    #7,d0 ? ?;Truncates to make max number of demo levels 7
139.  ?add.w d0,d0 ? ?;Doubles d0 for reading word addresses
140.  ?move.w    word_3DAC(pc,d0.w),d0;Load current level values
141.  ?move.w    d0,($FFFFFE10).w ?;Load current level and act value into RAM Address FFFFFE10
142.  ?addq.w    #1,($FFFFFFF2).w ?;Add 1 to the current demo level
143.  ?cmpi.w    #4,($FFFFFFF2).w ?;Compare 4 (max demo level) to current demo level
144.  ?bcs.s loc_3D5A ? ?;If not equal, branch
145.  ?move.w    #0,($FFFFFFF2).w ?;Sets to 0 (first demo level)
146.  
147. loc_3D5A: ?; CODE XREF: ROM:00003D52j
148.  ?move.w    #1,($FFFFFFF0).w ?;Demo mode flag to 1
149.  ?move.b    #8,($FFFFF600).w ?;Move 8 into master level trigger
150.  ?cmpi.w    #0,($FFFFFE10).w ?;Current level and act compared to Emerald Hill
151.  ?bne.s loc_3D74 ? ?;If not emerald hill, branch
152.  ?move.w    #1,($FFFFFFD8).w ?;If it is Emerald Hill move 1 into 2 player mode
153.  
154. loc_3D74: ?; CODE XREF: ROM:00003D6Cj
155.  ?move.b    #3,($FFFFFE12).w ?;Sonics lives init to 3
156.  ?move.b    #3,($FFFFFEC6).w ?;Tails lives init to 3
157.  ?moveq #0,d0 ? ?;Move 0 to d0 for variable clears
158.  ?move.w    d0,($FFFFFE20).w ?;Rings init
159.  ?move.l    d0,($FFFFFE22).w ?;time init
160.  ?move.l    d0,($FFFFFE26).w ?;Score counter (HUD)init
161.  ?move.w    d0,($FFFFFED0).w ?;Tails' rings to 0
162.  ?move.l    d0,($FFFFFED2).w ?;Tails' time to 0
163.  ?move.l    d0,($FFFFFED6).w ?;Tails' score to 0
164.  ?move.l    #$1388,($FFFFFFC0).w;Score needed for lives (sonic)
165.  ?move.l    #$1388,($FFFFFFC4).w;Score needed for lives (tails)
166.  ?rts  
167. ; ???????????????????????????????????????????????????????????????????????????
168. word_3DAC: ? ? ?;demo levels and level order
169.  ?dc.w ?0 ? ?;emerald hill
170.  ?dc.w ?$D00 ? ?;chemical plant
171.  ?dc.w ?$F00 ? ?;aquatic ruin
172.  ?dc.w ?$C00 ? ?;casino night
173.  
174. ; ??????????????? S U B R O U T I N E ???????????????????????????????????????
175.  
176.  
177. sub_3DB4: ? ? ? ?;Subroutine for the miles cheat
178.  ?lea   (byte_3DEE).l,a0 ?;set a0 to the address of the command list (below)
179.  ?move.w    ($FFFFFFD4).w,d0 ?;the step of the cheat that has been done
180.  ?adda.w    d0,a0 ? ?;Adds d0 to a0 - add the current step to the command list value to read
181.  ?move.b    ($FFFFF605).w,d0 ?;Puts current buttons being held into d0
182.  ?andi.b    #$F,d0 ? ?;Checks for up down, left and right.
183.  ?beq.s locret_3DEC ? ? ? ? ? ? ? ?;if none of these are pressed, exit
184.  ?cmp.b (a0),d0 ? ?;if any of them are pressed, compare the button pressed to the command value needed (check it's the right button)
185.  ?bne.s loc_3DE6 ? ? ? ? ? ? ? ? ?;if it's the wrong button, set to 0
186.  ?addq.w    #1,($FFFFFFD4).w ?;if it's the right button, add 1 to the current command needed ($FFD4)
187.  ?tst.b 1(a0) ? ?;check the first byte after a0 against 0
188.  ?bne.s locret_3DEC ? ?;if it's not equal, exit
189.  ?bchg  #7,($FFFFFFF8).w ?;sets $FFF8 to 0 (unsets the 7th bit) (sets miles cheat on)
190.  ?move.b    #-$4B,d0 ? ?;puts sound effect to play into d0
191.  ?bsr.w sub_1370 ? ?;play the sound effect number in d0
192.  
193. loc_3DE6: ? ? ? ?; CODE XREF: sub_3DB4+18j
194.  ?move.w    #0,($FFFFFFD4).w ?;set $FFD4 (miles cheat current button) to 0
195.  
196. locret_3DEC: ? ? ?;exit
197.  ?rts

 

Go ahead, that's what SHIT's for =P