After getting my head around object placement in a previous thread, I've been fiddling with AspectEdit trying to modify a Sonic Chaos level (no real mod plans, just to see what can be done really). It's harder than Sonic 2 as at least to my knowledge, there's no disassembly so you just have to just use offsets in the ROM. I'm using @Hivebrain's list here. https://forums.sonicretro.org/index.php?threads/sonic-chaos-hacking.24311/#post-557304 So Turquois Hill Act 1 Palette at 0x3B6AD Tileset at 0x40F9E 32x32 mappings at 0x44000 (not 100% sure about this one!) Level layout at 0x48000 Then a bit of trial and error with width/height/tile offset gave me width 128 height 32 tile offset 192 And that gets me... this! So near and yet so far. Only the palette is incorrect. Does anyone know any other sources for the location of palettes in the rom? Someone made those pretty maps in the map section, so presumably at least one person knows! :D Admittedly I haven't actually tried changing something and saving back to the ROM yet, but one problem at a time and all that...
It seems that offset is correct for the foreground objects (apparently just the rings and monitors) but not background. But I tried the palette labelled 'THZ - Sonic' in Hivebrain's list and we're looking good. Success! The level layout is saved out as a separate bin file, you need to paste the bytes back in at the appropriate offset to add it into the game, behold 4 new ring monitors at the start of THZ1
If anyone else is interested in trying it out, here are the various offset's I'm using. So far I've only tested it on THZ1, THZ3 and APZ2. EDIT - now tested all acts up to AP3 and added a couple of special stages EDIT 2 - fixed GPZ3 layout typo, it's 4B897 (not 4B987, ugh...) EDIT 3 - added EEZ 32x32 mapping offset, width, height Code (Text): -level layout offset 48000 - THZ1 layout 48BA9 - THZ2 layout 49815 - THZ3 layout 49C25 - GPZ1 layout 4AA00 - GPZ2 layout 4B897 - GPZ3 layout 54000 - SEZ1 layout 54CC8 - SEZ2 layout 53460 - SEZ3 layout 559D4 - MGHZ1 layout 566B8 - MGHZ2 layout 572FB - MGHZ3 layout 5C000 - APZ1 layout 5C7C1 - APZ2 layout 57AF3 - APZ3 layout 5CF3A - EEZ1 layout 5DB73 - EEZ2 layout 5E853 - EEZ3 layout 68000 - SS1 layout 685A8 - SS2 layout 68848 - SS3 layout 68C1E - SS4 layout 69258 - SS5 layout -mappings offset 44000 Mappings THZ1 45640 Mappings GPZ 46A40 Mappings SEZ 50000 Mappings MGHZ 51320 Mappings APZ 524E0 Mappings EEZ 6C000 Mappings SS1/2/4 6CF60 Mappings SS3/5 -tileset offset 40F9E tileset THZ 42478 tileset GPZ 60000 tileset SEZ 619F0 tileset MGHZ 58000 tileset APZ 59800 tileset EEZ 64000 tileset SS1/2/4 65590 tileset SS3/5 -foreground palette offset 3B6AD - THZ 3B6BD - GPZ 3B6CD - SEZ 3B6DD - MGHZ 3B6ED - APZ 3B6FD - EEZ 3B76D - SS1/2/4 3B77D - SS3 3B78D - SS5 -background palette offset 3B79D - THZ 3B7AD - GPZ 3B7BD - SEZ 3B7CD - MGHZ 3B7DD - APZ 3B7ED - EEZ 3B8AD - SS1/2/4 3B8BD - SS3/5 -tile offset 192 for all levels -width/height THZ1 width 128 height 32 THZ2 width 128 height 32 THZ3 width 80 height 16 GPZ1 width 160 height 24 GPZ2 width 128 height 32 GPZ3 width 80 height 16 SEZ1 width 128 height 32 SEZ2 width 128 height 32 SEZ3 width 128 height 32 MGHZ1 width 128 height 32 MGHZ2 width 128 height 32 MGHZ3 width 120 height 24 APZ1 width 168 height 24 APZ2 width 128 height 32 APZ3 width 80 height 16 EEZ1 width 128 height 32 EEZ2 width 128 height 32 EEZ3 width 112 height 32 SS1 Width 512 Height 8 SS2 Width 24 Height 64 SS3 Width 128 Height 24 SS4 Width 256 Height 16 SS5 Width 48 Height 32
So.. this was my mistake. I accidentally got the palettes mixed up and I guess I never realized it until now. Be sure to add this to the hacking page if you haven't yet. Also just a warning, I could never get Gigalopolis' Act 1 level layout to open in Aspect Edit and I still don't know why it's the only level that won't work in the program. Both the Game Gear and SMS versions have this problem.
No worries @Ravenfreak, I didn't really think that no one had tried this before, just that it wasn't necessarily all written down! GPZ1 (on SMS at least) does work for me using the offsets above, but it's got an unusual width of 160 (which I had to add manually, it's not one of the standard selections). Another daft thing I did was add a floor to special stage 1 then run along the bottom of the screen to the emerald! My vague plan at the moment is to do a little mod where I make some small layout changes and hide a single extra life in each act for people to try and find. Just as a way to show off the editor. In your notes do you have an offset for Electric Egg's 32x32 mappings? Hivebrain's list doesn't have those which means I can't currently open any electric egg layouts properly! EDIT - oh and the mysterious floating green wall block in Special Stage 1/2/5 acts like an aqua planet underwater tunnel door (where you push it open and the current sucks you through).
I've opened all the acts except Electric Egg zone and the only one I'm having a problem with is GPZ3, which fits width 80 height 16, but is missing the top row of the level, which probably means the offset for the layout itself is wrong for that one. I've also updated my post above with all the width/height values that I've found to work so far. Hopefully I can work out Electric Egg mappings and complete the set! I also can't get special stage 2 to display properly. It's unusually narrow and AspectEdit doesn't like a width smaller than 16. Always possible that it isn't actually stored in the ROM like that anyway, I'm new to all this so not sure. EDIT - Dumb mistake, for smaller widths, you have to shrink the window containing the image down to the right size or it doesn't wrap correctly. So Special Stage 2 is width 24, height 64
Finally figured out why GPZ3 was dodgy, it was a silly typo. Correct offset is 0x4b897, I've updated the code snippet above. Still need to figure out the Electric Egg 32x32 mapping offset to complete the set. Also, a long shot, but Aspect Edit supports Triple Trouble as well. @Glitch documented the various offsets required to edit MJZ1 in another thread but I couldn't find a full list anywhere. Has anyone ever attempted such a list?
Thanks @Glitch, applying your notes to Sonic Chaos meant I finally figured out where I was going wrong trying to calculate the offset for the EEZ 32x32 mappings The magic offset is 0x524E0, hooray! Looking forward to mucking about with Triple Trouble when I've got a bit more time.
OK, I'm getting the hang of it. Managed to work my way through GTZ1 level layout - 480C0 32x32mapping - 44000 Tileset - 404C4 Foreground Palette - 3B8DC Background Palette - 3BABC Offset 192 Width/Height 168/24 EDIT - the full list of offsets can be found here AspectEdit with Sonic Triple Trouble | Sonic and Sega Retro Forums (sonicretro.org)
I've been documenting the Sonic Chaos monitor subtypes to see if there's anything interesting in there as part of my endless mission to find all the 1 ups in all the classic Sonics. Monitor ID is 10 in Chaos, and the object format is the same as Sonic 2, 9 bytes per object starting at 0x705ae for THZ1. 00 = blank/static (not used) 01 = 10 rings 02 = Extra life 03 = speed shoes 04 = rocket shoes 05 = clock monitor (does nothing in normal game) 06 = invincibility The object graphics then repeat but have no effect when collected (except for speed shoes giving you rockets for some reason, clearly these values were not intended for use in game!) 07 = 10 rings (not used - does nothing if collected) 08 = Tails extra life (not used - does nothing if collected) 09 = speed shoes (not used - gives rocket shoes if collected?) 0a = rocket shoes (not used - does nothing collected) 0b = clock item (not used - does nothing if collected) 0c = invincible (not used - does nothing if collected) 0d, 0e, 0f = garbled graphics, does nothing if collected.
