overview
block 00
block 01
block 02
block 03
block 04
block 05
block 06
block 08
block 09
block 10
block 11
block 12
block 15
block 16
block 17
block 18
block 19
block 20
block 21
block 22
block 23
block 24
block 25
block 26
block 27
block 30

threads
weapons
pickups
sprites
vehicle colors
vehicle types
vehicle mods
locations
savehouses
map
legend

Overview

Also, a lot of documentation can be found here at gtamodding.com.

The savegame files are stored in the files "<my documents>\GTA San Andreas User Files\GTASAsfn.b" with n from 1 to 8.
The location of the my documents folder can be found in the Windows registry key "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders\Personal".
BlockSizeDescription
00312First block
01varScript
02varObjects
039159Garages
0411?
05var?
0619923Pickups
070
08359Respawn locations
097000Radar blibs
1018892Zones
11160Gang Weapons
12varCar Generator
130
140
1544Money
161940Stats
176724?
1826316Crap
19640?
20104Tags
21259Roadblocks
22552Clothes
2392Gang wars
244764Unique Jumps
25varTeleport
263836Crap
273590 / 3592?
280
290
30varCrap / Padding

Savegame layout

  1. Block 0 to 29 (inclusive)
  2. Block 15, 16 and 17
  3. Block 30
  4. A 4-byte integer with the sum of all the preceding bytes

Before every block in the file is the ascii string "BLOCK", so the file contains 34 times "BLOCK".