Welcome to Data Crystal's new home! Data Crystal is now part of the TCRF family (sort of).
The wiki has recently moved; please report any issues in Discord. Pardon the dust.
The wiki has recently moved; please report any issues in Discord. Pardon the dust.
EarthBound Zero/RAM map: Difference between revisions
Jump to navigation
Jump to search
MOTHERrocks (talk | contribs) (I now know where the checksum is (but not what it is)) |
MOTHERrocks (talk | contribs) (the checksum is figured out!) |
||
| Line 30: | Line 30: | ||
=SRAM (save data)= | =SRAM (save data)= | ||
===Unknown=== | ===Unknown=== | ||
* 0000-13FF: '''Unknown''' | * 0000-13FF: '''Unknown''' | ||
===Checksum=== | |||
The 2-byte checksum is calculated by subtracting each byte after it (0x300 for each save, so 0x29E bytes to subtract), then running it through mod 0x10000. | |||
Here is an example Python program that calculates it: | |||
<pre> | |||
def calculate_checksum(handle, base = 0x1700): | |||
handle.seek(base) | |||
checksum = int.from_bytes(handle.read(2), "little") | |||
calculated_checksum = 0x0 | |||
for number in range(0x300 - 0x2): | |||
calculated_checksum = (calculated_checksum - int.from_bytes(handle.read(2), "little")) % 0x100 ** 2 | |||
return calculated_checksum | |||
calculate_checksum(open("file.sav", "rb")) | |||
</pre> | |||
* 1400-1401: Checksum | |||
===Main data=== | ===Main data=== | ||
* 1402-1403: '''Unknown''' | * 1402-1403: '''Unknown''' | ||
* 1404-1407: Position | * 1404-1407: Position | ||
Revision as of 18:36, 27 September 2023
The following article is a RAM map for EarthBound Zero.
RAM
| RAM | Purpose |
|---|---|
| 0x0006 | Part of an instruction for "copy protection". $E5 on checksum failure. $00 to bypass. "Correct"/non-hack value unknown. |
| 0x0015 | Used for assigning area to objects? |
| 0x0060 | HP target value for stat increase during level up |
| 0x0611 | Looks like the first EXP byte, but changing it even mid-battle will result in insta-death. Anti-cheat? |
| 0x0818-B | The X and Y coordinates, stored strangely; see below |
Coordinates
The coordinates in RAM to not correspond to coordinates in the rest of the game. To convert it, run this Python code (in this example, bytes $818-B are `80 19 C0 2D`):
# replace with the values from the RAM ram_x = 0x1980 ram_y = 0x2dc0 real_x = ((byte1 << 8) | (byte0 & 0xC0)) >> 2 real_y = ((byte3 << 8) | (byte2 & 0xC0) - 0x2000) >> 2
SRAM (save data)
Unknown
- 0000-13FF: Unknown
Checksum
The 2-byte checksum is calculated by subtracting each byte after it (0x300 for each save, so 0x29E bytes to subtract), then running it through mod 0x10000. Here is an example Python program that calculates it:
def calculate_checksum(handle, base = 0x1700):
handle.seek(base)
checksum = int.from_bytes(handle.read(2), "little")
calculated_checksum = 0x0
for number in range(0x300 - 0x2):
calculated_checksum = (calculated_checksum - int.from_bytes(handle.read(2), "little")) % 0x100 ** 2
return calculated_checksum
calculate_checksum(open("file.sav", "rb"))
- 1400-1401: Checksum
Main data
- 1402-1403: Unknown
- 1404-1407: Position
- 1408-140B: Current party members
- Each number corresponds to an ally in Ally data, 0 means empty and skips to the next value.
- 140C-140F: Unknown
- 1410-1411: Current money
- 1412-1414: Money in bank
- 1415-141F: Unknown
- 1420-1430: Your name (the player name, not Ninten's name)
- 1431-143F: Unknown
Ally status
This is documented below.
- 1440-147F: Ninten
- 1480-14BF: Ana
- 14C0-14FF: Lloyd
- 1500-153F: Teddy
- 1540-157F: Pippi
- 1580-15BF: EVE
- 15C0-15FF: Flying Man
Other
- 1600-1688: Unknown
- 1689-1983: Favorite food name
- 1984-16AF: Unknown
- 16B0-16CF: Items in storage
Unknown
- 16D0-1FF0: Other
Ally state
Each ally's state is stored at a place corresponding to the character, see the above section
- 00: Unknown (unused?)
- 01: Status condition
- Bit 0: Cold
- Bit 1: Poisoned
- Bit 2: Puzzled
- Bit 3: Confused
- Bit 4: Sleeping
- Bit 5: Paralyzed
- Bit 6: Stone
- Bit 7: Unconscious (can be applied even when HP isn't at 0)
- 02: Unknown
- 03-04: Max HP
- 05-06: Max PP
- 07-08: Offense
- 09-0A: Defense
- 0B: Fight
- 0C: Speed
- 0D: Wisdom
- 0E: Strength
- 0F: Force
- 10: Level
- 11-13: Experience
- 14-15: Current HP
- 16-17: Current PP
- 18-19: Unknown
- 20-27: Items
- 28: Weapon
- 29: Coin
- 2A: Ring
- 2B: Pendant
- 30-37: Learned PSI
- 38-3E: Name
- 3F: Unknown (unused?)
Internal Data for EarthBound Zero
| |
|---|---|