Okay, lessons learned. Back up my stuff. Basically, some of you may know that I have been working on a disassembly of the game 'Streets of Rage' for the past 6 months. Well today, my hard drive decided it didn't want anything else to do with it and decided to pack itself in. So while I'm foaming at the mouth, trying to salvage what I can to see if I haven't wasted 6 months of my life, I thought I might as well post what I've learned about Streets of Rage, while I can still remember some of the specifics. RAM Addresses: $FFB800 - Start of object RAM. Each entry is $80 bytes in size, and the space is $1000 bytes in size, which gives you $20 (32) objects to use at a time, excluding collectibles. During regular gameplay, $FFB800 is generally reserved for the first player, while $FFB880 is reserved for the second, meaning that the start of object RAM for everything else is $FFB900. The SSTs that I can remember are 00 (object ID, see below), 04 is the mappings offset, $10 is the X-axis coordinates (word) and $14 is the Y-axis coordinates (word). $18 is an artificial third axis which measures your height. Used when jumping. Setting this too low or high can cause the character to die, except for Round 8. $30 is the object's routine counter, $32 is the object's health, where the object is killed if it goes below 0 ($FFFF), and $34 is the object's attack power (i.e. how much damage it does to you). $FFC980 - Seperate object RAM space that only seems to store bats and knives. $FFCD00 - Seperate object RAM space that stores items you can pick up (presumably due to different SST handlers needed), with exception of what was listed above. $400 bytes in size, which means you can only have 8 collectible objects on the screen at the same time. $FFF00A - Updates the current track playing. $FFF400 - Normal palette buffer. DMAed to CRAM during VBlank, depending on whether $FFFA01 is set or not. $80 bytes in size. $FFF480 - Target palette RAM space. Used by fading routines to fade the palettes at $FFF400, until the data matches the target palette. $80 bytes in size. $FFFA01 - CRAM DMA flag. When set to 1, whatever's stored in the normal palette buffer will be DMAed to CRAM during the next Vint. $FFFF02 - Level flag. $FFFF1B - Player 1's continues. $FFFF1D - Player 2's continues. $FFFF20 - Player $1's lives. $FFFF21 - Player 1's police car amount. $FFFF23 - Player 2's lives. $FFFF24 - Player 2's police car amount. $FFFF46 - VDP Register 1 value, enables display. $FFFF48 - VDP Register 1 value, disables display. $FFFFC7 - Difficulty 00 - Easy 01 - Normal 02 - Hard 03 - Hardest (No mania options as rumoured ;V) Music Hacking: Whatever's written to $FFF00A will play. There is a subroutine that handles playing tracks when the IDs are stored to d7, located at $01069E. Music IDs: $00-$7F - Stops the music. $80 - / $81 - Round 1 $82 - Game Over $83 - Title $84 - Round 3 $85 - Round 5 $86 - Round 7 $87 - Boss $88 - Round 8 $89 - Round 6 $8A - Select $8B - Round 2 $8C - Round 4 $8D - Name Entry $8E - Round Clear $8F - Bad Ending $90 - Last Boss $91 - Good Ending $92-$9F - Blank ; Start of Sound Effects $A0 - SE 1 $A1 - SE 2 $A2 - SE 3 $A3 - SE 4 $A4 - SE 5 $A5 - SE 6 $A6 - SE 7 $A7 - SE 8 $A8 - SE 9 $A9 - SE 10 $AA - SE 11 $AB - SE 12 $AC - SE 13 $AD - SE 14 $AE - SE 15 $AF - SE 16 $B0 - SE 17 $B1 - SE 18 $B2 - SE 19 $B3 - SE 20 $B4 - SE 21 $B5 - SE 22 $B6 - SE 23 $B7 - SE 24 $B8 - SE 25 $B9 - SE 26 $BA - SE 27 $BB - SE 28 $BC - SE 29 $BD - Pause Jingle (Not in sound test) $BE - SE 30 $BF - SE 31 $C0 - SE 32 $C1 - SE 33 $C2 - SE 34 $C3 - SE 35 $C4 - SE 36 $C5 - SE 37 $C6 - SE 38 $C7 - SE 39 $C8 - SE 40 $C9 - SE 41 $CA - SE 42 $CB - SE 43 $CC - SE 44 $CD - SE 45 $CE - SE 46 $CF - 'GO' Buzzing (Not in sound test) ; Start of Voices $D0 - Adam's voice (Voice 1) $D1 - Unused, higher pitch variant of Adam's voice (Not in sound test). $D2 - Voice 3 $D3 - Voice 4 $D4 - Voice 5 $D5 - Voice 6 $D6 - Voice 7 $D7 - Voice 8 $D8 - Voice 9 $D9 - Voice 10 $DA - Boss defeated SE (Not in sound test) $DB - Axel's voice (Voice 2) $DC-$DF - Blank ; Special Flags $E0 - Fade out music. $E1 - Stop Music $E2 - Stop Sound Effects $E3 - Stop sound. $E4 - '' Palette Editing: Streets of Rage uses a different method compared to the usual 0BGR method. It is encoded so that the subroutine it is loaded to knows exactly what palette line to load it to, which entry in that palette line to load it to (to where it is then positioned appropriately in the palette buffer) and the length of the data string. Rather than the typical bitfield: 0000 BBB0 GGG0 RRR0 ...It uses: XXXX BBBN GGGN RRRT For instance, take the value $6EFE for instance: XXXX BBBN GGGN RRRT 0110 1110 1111 1110 The XXXX in this case is represented by the number 6. Palette entries are $0-$F, so this one is loaded to palette entry $6 in this case. Next, the first N is 0, while the second N is 1. Group them together, and you get 01. Now look at this chart: 00 - Palette line 0 01 - Palette line 1 10 - Palette line 2 11 - Palette line 3 This shows which palette line the palette will end up in. Since this is 01, it will end up in the "1st" one. You can usually tell if an N bit is checked by it having an odd number in the number it's representing in hex. So for example, the second digit 'E' isn't odd, so the N bit isn't checked, while the third digit is, so the N bit is checked. You can't have odd numbers for palettes, so the game makes use of it before it is written to the palette buffer. In this case, T isn't checked, so the game will treat the following word as a palette, and will try to decode it. If it's the end of the palette data, set T to 1 (or put an odd number into the final digit). Afterwards, the original data is anded by $0EEE (White, as you can't get a higher value than that), and the value is positioned appropriately in the palette buffer. $6EFE anded by $0EEE is $0EEE, so white will be moved to palette line 1, entry 6 during the next CRAM DMA in VBlank (Setting $FFFA01 to 1 activates it, otherwise CRAM DMA is skipped). SUBROUTINE ADDRESSES: $010538 - Loads the target palette into a2, sets the CRAM DMA flag and then decodes the palettes into the buffer at $010548. $01053E - Loads the palette buffer into a2, sets the CRAM DMA flag and then decodes the palettes into the buffer at $010548. $010548 - Palettes are decoded here into the appropriate position relative to a2. Objects: The object list is found at $00B238 and each entry is a word in size. The entries go in the following order: Object Lists: 01 - Main character 02 - 03 - 04 - 05 - Police car 06 - Character select cursor controller 07 - Main characters on the select screen 08 - Knife 09 - Bottle 0A 0B - Pipe 0C - Pepper 0D - 0E - 0F - 10 - 11 - Phone box 12 - 13 - 14 - 15 - Statue 16 - Can 17 - 18 - Stacks of tyres 19 - Barrel / Oil Drum 1A - 1B - 1C - Luminous Stand 1D - Roadblock 1E - 1F - 20 - Galsia holding knife 21 - Passive Galsia 22 - Galsia 23 - Galsia holding long weapon 24 - Signal 25 - Hakuyo 26 - Nora 27 - Jack 28 - Jack's Axes/Fire sticks 29 - 2A - Group of 3 Hakuyos 2B - 2C - 2D - 2E - 2F - 30 - Abadede 31 - 32 - 33 - Mr X's body sitting down 34 - Mr X's legs sitting down 35 - 36 - 37 - Mr X defeated? 38 - 39 - 3A - 3B - 3C - 3D - 3E - 3F - Money 40 - Gold bars 41 - Wooden crates 42 - Industrial crushers 43 - 44 - 45 - Dinner table 46 - 47 - Meat 48 - 49 - 4A - Baseball bat 4B - Apple 4C - Extra life 4D - 4E - Round 3's trees 4F - Mini police car 50 - 51 - Door and window (Round 7) 52 - 53 - 54 - Garage door 55 - Souther 56 - Antonio 57 - Bongo 58 - Yasha & Onihime (separate objects, 2 are loaded at a time) ; There's more, but this is all I recognise, ATM. This stuff is pretty bare-bones, but it's all I can remember at the moment. Expect it to be updated should I ever get hold of my source again. I do have a lot of cool stuff that I would like to post (song locations, more on music hacking, screen modes, art locations, etc.), so fingers crossed that my HDD isn't too badly damaged.