====== Editing the Initial Savegame ======

Now you can start anywhere you want! What a thought!

===== Location and Format =====

The data starts at 0x4E64 in ROM, and is (somewhat) nicely organized.

All 16-bit values are little-endian.

^ Address ^ Default ^ Use |
^ Samus' position |||
| 0x4E64 | $D4 | Y pos, pixels |
| 0x4E65 | $07 | Y pos, screen |
| 0x4E66 | $48 | X pos, pixels |
| 0x4E67 | $06 | X pos, screen |
^ Camera position |||
| 0x4E68 | $C0 | Y pos, pixels |
| 0x4E69 | $07 | Y pos, screen |
| 0x4E6A | $40 | X pos, pixels |
| 0x4E6B | $06 | X pos, screen |
^ Tileset Definitions |||
| 0x4E6C | $7520 | Sprite graphics pointer (bank 6) |
| 0x4E6E | $07 | BG graphics bank |
| 0x4E6F | $6000 | BG graphics pointer |
| 0x4E71 | $5280 | Metatile data pointer (bank 8) |
| 0x4E73 | $4580 | Collision data pointer (bank 8) |
| 0x4E75 | $0F | Map Bank (9-F) |
^ Solidity indexes |||
| 0x4E76 | $64 | Samus |
| 0x4E77 | $64 | Enemies |
| 0x4E78 | $64 | Weapons |
^ Equipment |||
| 0x4E79 | $00 | Samus' items |
| 0x4E7A | $00 | Samus' beam |
| 0x4E7B | $00 | Energy tanks |
| 0x4E7C | $99 | Current energy |
| 0x4E7D | $00 | Current energy (e-tanks) |
| 0x4E7E | $0030 | Max Missile Count* |
| 0x4E80 | $0030 | Current missile count |
^ Misc. |||
| 0x4E82 | $01 | Direction Samus is facing (pointless?) |
| 0x4E83 | $02 | Acid damage |
| 0x4E84 | $08 | Spike damage |
| 0x4E85 | $47 | Real Metroid count (BCD) |
| 0x4E86 | $04 | Song to play |
| 0x4E87 | $00 | In-game timer (Minutes) |
| 0x4E88 | $00 | In-game timer (Hours) |
| 0x4E89 | $39 | Onscreen Metroid count (BCD) |

*00 is at 0x4E7F and 30 is at 0x4E7E in the ROM, resulting in inversion(it appears as $3000 in the ROM). This could cause confusion if not clarified.

===== Simple Procedure =====

If you're creating you're own hack, one easy way to do this is to:
  - Go to wherever you want the start to be
  - Poke the value 0x09 to the address 0xFF9B in RAM (to force the game to save)
  - Copy the saved game from SRAM to the location in ROM
  - Do some fine tuning as desired.

Check [[return_of_samus:data_locations:ram_map |RAM map]] for more details.

Some limitations may apply.