User:Sherkel/RNG Notes
Well well well, how the turntables...
Generation III
| Method | PID1 | PID2 | IV1 | IV2 |
|---|---|---|---|---|
| 1 | 1 | 2 | 3 | 4 |
| 2 | 1 | 2 | 4 | 5 |
| 4 | 1 | 2 | 3 | 5 |
| Colo/XD | 4 | 5 | 1 | 2 |
Why does this multiplier look so...familiar?
Reason for Method 4: VBlank takes priority when it occurs; Box probably doesn't emulate the CPU timing well enough for uninterrupted Method 1
XD LCG: increment 269EC3, multiplier 343FD
ID in FRLG is 0x04000104 (Timer1 -- https://www.cs.rit.edu/~tjh8300/CowBite/CowBiteSpec.htm#Memory-Mapped%20Hardware%20Registers ); SID is upper 16 of RNG state
FRLG initial seed is Timer1 as well The timer starts counting when the screen changes to the "Press Start"-Screen. This is initiated by the first button press or waiting till intro is finished. Once it started counting, it will do so until the initial seed has been determinated. A soft reset will have the same effect as if you switch off the GBA. ~ flovv
http://www.coranac.com/tonc/text/timers.htm
Method H determines nature first (to account for Synchronize and the routine described here), then conducts a "hunt" for a PID that matches it in the possible ones for the numbered method, then generates the two IV halfwords based on above
How the hunt (also in Gen 4's Method J/K) works: The game takes a seed and does (seed >> 16) % 0x19. Then it starts making PIDs and doing PID % 0x19 and it keeps making PIDs until it gets a match to that original (seed >> 16) % 0x19.
Method H is rarely H-1 as it's slow enough to fill up VCount
In some maps, the LCG advances exactly twice per frame
blocks of three 31s (0b11111 11111 11111) are bold
| Frame | 32bit | 16bit high | Method 1 PID | Method 1 IVs | Method 1 IVs (IV1, IV2) | Method 2 IVs | Method H-2 PID | Method H-2 IVs |
|---|---|---|---|---|---|---|---|---|
| -1 | 35CC77B9 | 35CC | EF72C69F | 04AF7FFF | ? | 3FFFFFFF | ||
| 0 | C69FB838 | C69F | 7942EF72 | 3FFFFFFF | FFFFFFFF | 3FFFA899 | E1695F0A(*) | 34AC44F6 |
| 1 | EF72E04B | EF72 | FFFF7942 | 3FFFA899 | FFFFA899 | 30A27E81 | ||
| 2 | 7942BA62 | 7942 | FFFFFFFF | |||||
| 3 | FFFF982D | FFFF | 1158FFFF | |||||
| 4 | FFFFE19C | FFFF | D3E11158 | |||||
| 5 | 1158F7DF | 1158 | 6536D3E1 |
(*) E1695F0A is Timid and is the PID of "otherwise frame" 48
Generation V
Initial seeding: Time is in (decimal) 00SSMMHH HH from 00-11 (12-11AM), 52-63 (12-11 PM). 0XDDMMYY date X=weekday, starting at 0 ~ Kaphotics
Kazowar: OFFSETS BLACK (add 0x20 to offset for white) 02216084 = SEED 0221608C = 0x5D588B656C078965 02216094 = 0x0000000000269EC3
SEED = (0x5D588B656C078965 * SEED) + 0x0000000000269EC3;