Super Mario Bros.:Notes
Player physics/movement algorithm
- Signed vertical velocity in whole pixels at 0x009F
- Unsigned(?) vertical velocity in fractions of a pixel at 0x0433
- Gravity varies, see RAM map for 0x0709/070A
- Basic integration of vertical velocity (when player not grounded)
- The gravity (see above) is added to 0x0433 with ADC.
- If the carry flag is set (addition into 0x0433 overflowed), a whole pixel (0x01) is added to 0x009F.
- Note: 0x009F is clamped to a maximum positive value of 0x05, but 0x0433 is NOT cleared. This could lead to various round-off errors leading into the next jump (unconfirmed).
- An instant velocity impulse is set, e.g. 0xFB, propelling the sprite upward.
- Gravity is also modified, e.g. set to 0x30 (weaker) when going up and then to 0xA8 (stronger) when falling down.
- These values VARY based on jump power/horizontal velocity. See RAM map for some possible values. Exact algorithm yet unknown.
Hacking the End-of-Level Castles
1) Get some graphing paper, and start cordoning 2x2 squares. Make a 5x5 block of such squares (10x10 overall).
2) Reading right-to-left, from the top row down, you've got the metatile defined by $17DF, $17E0, $17E1, etc......, $17F7.
3) This linear string of 25 bytes can be represented on your graph paper like this:
5 4 3 2 1 10 9 8 7 6 15 14 13 12 11 20 19 18 17 16 25 24 23 22 21
The first byte in this string codes for the upper-rightmost metatile, the second byte codes for the metatile directly to #'s left, etc.
4) The large castles at the end of every X-3 level (and the beginning of most X-1 levels) are simply the small castle stacked on top of another, slightly taller one. This taller castle is 6 metatiles high and five metatiles wide, and is coded in a similar right-to-left, top-down fashion. Its linear byte sequence begins at $17F8.
5) The little side-sections on the X-3 castle type are actually the same background image that occurs throughout World 8-3. This image is 1 metatile wide and eleven metatiles high (although it only appears to be six metatiles high since the first five bytes are assigned transparent "00" values). Its coding begins at $13CE and ends at $13D8.
Mario Palette Information
There are four main palettes each with a unique set of 8 colors defined (background, pipe, cloud, brick, mario, green enemy, red enemy, brown enemy)
4 alternate palettes
- Night (sets background)
- Snow (sets background, pipe color)
- Night/Snow 1 (sets background, pipe colors)
- Night/Snow 2 (uses castle palette for everything but background)
- Mushroom type sets pipe color (over rides all other pipe color settings)
- Bowser has special palette
00 - Blank 01 - Black Metatile 02 - Bush Left 03 - Bush Middle 04 - Bush Right 05 - Mountain Left 06 - Mountain Left Bottom/Middle Center 07 - Mountain Middle Top 08 - Mountain Right 09 - Mountain Right Bottom 0A - Mountain Middle Bottom 0B - Bridge Guardrail 0C - Chain 0D - Tall Tree Top, Top Half 0E - Short Tree Top 0F - Tall Tree Top, Bottom Half 10 - Warp Pipe End Left, Points Up 11 - Warp Pipe End Right, Points Up 12 - Decoration Pipe End Left, Points Up 13 - Decoration Pipe End Right, Points Up 14 - Pipe Shaft Left 15 - Pipe Shaft Right 16 - Tree Ledge Left Edge 17 - Tree Ledge Middle 18 - Tree Ledge Right Edge 19 - Mushroom Left Edge 1A - Mushroom Middle 1B - Mushroom Right Edge 1C - Sideways Pipe End Top 1D - Sideways Pipe Shaft Top 1E - Sideways Pipe Joint Top 1F - Sideways Pipe End Bottom 20 - Sideways Pipe Shaft Bottom 21 - Sideways Pipe Joint Bottom 22 - Seaplant 23 - Blank, Used On Bricks Or Blocks That Are Hit 24 - Flagpole Ball 25 - Flagpole Shaft 26 - Blank, Used In Conjunction With Vines 40 - Vertical Rope 41 - Horizontal Rope 42 - Left Pulley 43 - Right Pulley 44 - Blank Used For Balance Rope 45 - Castle Top 46 - Castle Window Left 47 - Castle Brick Wall 48 - Castle Window Right 49 - Castle Top W/ Brick 4A - Entrance Top 4B - Entrance Bottom 4C - Green Ledge Stump 4D - Fence 4E - Tree Trunk 4F - Mushroom Stump Top 50 - Mushroom Stump Bottom 51 - Breakable Brick W/ Line 52 - Breakable Brick 53 - Breakable Brick (Not Used) 54 - Cracked Rock Terrain 55 - Brick With Line (Power-Up) 56 - Brick With Line (Vine) 57 - Brick With Line (Star) 58 - Brick With Line (Coins) 59 - Brick With Line (1-Up) 5A - Brick (Power-Up) 5B - Brick (Vine) 5C - Brick (Star) 5D - Brick (Coins) 5E - Brick (1-Up) 5F - Hidden Block (1 Coin) 60 - Hidden Block (1-Up) 61 - Solid Block (3-D Block) 62 - Solid Block (White Wall) 63 - Bridge 64 - Bullet Bill Cannon Barrel 65 - Bullet Bill Cannon Top 66 - Bullet Bill Cannon Bottom 67 - Blank Used For Jumpspring 68 - Half Brick Used For Jumpspring 69 - Solid Block (Water Level, Green Rock) 6A - Half Brick (???) 6B - Water Pipe Top 6C - Water Pipe Bottom 6D - Flag Ball (Residual Object) 80 - Cloud Left 81 - Cloud Middle 82 - Cloud Right 83 - Cloud Bottom Left 84 - Cloud Bottom Middle 85 - Cloud Bottom Right 86 - Water/Lava Top 87 - Water/Lava 88 - Cloud Level Terrain 89 - Bowser's Bridge C0 - Question Block (Coin) C1 - Question Block (Power-Up) C2 - Coin C3 - Underwater Coin C4 - Empty Block C5 - Axe
This data format represents title screens and other static background layouts in a lot of games published by Nintendo. SMB uses it in ROM for the title screen and other strings (see ROM map) and in RAM for the transfer buffer.
An image consists of several packets, where each packet is as follows, followed by a 00 byte
0 VRAM destination address high byte (20-3F) 1 VRAM destination address low byte 2 Flags and length irnn nnnn ||++-++++- Length minus 1 (00: 1 byte; 3F: 64 bytes) |+-------- Run (0: 1-64 literal bytes follow; 1: 1 byte follows repeated 1-64 times) +--------- Increment (0: add 1 to VRAM address after each byte; 1: add 32) 3+ Data
|Internal Data for Super Mario Bros.|