To unlock the Infinite Rocket Launcher and the Gatling Gun (with infinite ammo), beat the game in under 2'30'00 with an A ranking and they will both appear in your item box when you start a new game and reach the R.P.D.

Their inclusion is basically a reward for your efforts, so that you can play through the game with the ability to destroy every undead zombie and creature you meet. The Infinite Rocket Launcher is especially fun.

On any scenario on the Normal difficulty, get to the RPD precinct without picking up any items. Before entering the RPD, head down the nearby stairs in the entrance courtyard and you will come across a zombie that was once Brad Vickers, the S.T.A.R.S. Alpha Team helicopter pilot from the first Resident Evil game (if you wish to know the events that led to his transformation into a zombie, play Resident Evil 3: Nemesis).

Brad has more stamina than a regular zombie and won't go down easily. However, keep firing at him and he'll eventually fall. Once you have done so, examine his body and you'll pick up a special key.

Once inside the RPD, head to the Darkroom once you have opened the hallway doors with the card key that Marvin Branagh gave you and examine the lockers. Use the special key on the lockers and you will be able to change your outfit. Leon gets a different police uniform and a hippie-like costume to choose from. Claire gets a cowgirl outfit and a new gun.

You can change your uniform to default any time you like.

Before you enter the Umbrella Laboratory, take the W. Box Key from the Vacant Factory. Inside the Umbrella Laboratory, head to the room opposite the one where the Giant Moth resides. Once inside this room, head to the lockers on your character's immediate left and open the fourth one using the W. Box Key.

Leon will find Magnum Parts inside.
Claire will find Flame Rounds inside.

4th Survivor mini game - Beat an A scenario with a A ranking and a B scenario with an A ranking.

Tofu mini game - Beat 4th Survivor with an A ranking, I believe.

Extreme Battle mode - Beat any A scenario and the following B scenario.

Unlock Ada Wong in Extreme Battle - Beat Extreme Battle with both Leon and Claire.

Unlock Chris Redfield in Extreme Battle - Beat Extreme Battle with Ada.

First you must go on difficulty normal from the begining.

Next you must not pick anything (bullets guns) up, until your'e at the police station.

A zombie should be at the stairwell, kill him and there should be key on him, get the key and go into the station.

Go see the guy laying on the floor in the room, get the card and unlock the doors.

Finally go through the door on the left of the statue, kill the licker and go into that safe place with the red room and the closet in the corner has the key you got.(it has 2 costumes which in my opinion, SUCK!)

Some Datel Codes
Clare Only
Eagle Stone: 800CC6DC 013A
Jaguar Stone: 800CC6E0 0137
Serpent Stone: 800CC6E4 0136
Gatling Gun: 800CC61C FF12
Rocket Launcher: 800CC618 FF11
Spark Shot: 800CC610 FF0E Leon Only
Custom Shotgun: 800CC674 FF08
Sub Machine Gun: 800CC67C FF0F

dual shock version only Infinite ammo, Go to the key config option screen where you can change your aimming to manual or auto. hold R1 while you tap the square botton 10 times to get infinite ammo. Note press select botton to open the option srceen to enter this cheat. the word auto or manual well turn red. have funn!

When you start the game on normal go through the game to the police station.

When you go down the stairs there will be a zombie down there.

If you notice it is brad from the first game.run past him up the other side of the stairs.go into the station and get the ammo on the desk.

Go back outside and the garden with the bushes right there when you walk out hit x.you will get a green herb.use it.

Now that you have full health and full ammo go back down the stairs.stoot brad unitl he dies or just shoot him a few times and wait for him to drop then he will climb on your leg.

Hit x unitil they stomp on his head.hit x by him and you will get a key.

The key is to be used in the dark room where you can change costumes and with clair you get a special gun.

Flick on the swiches in the following order to power up the weapon-storage room in the basement up,up,down,down,up

SAFE COMBINATION 2236