Call of Duty 4: Modern Warfare, generally known as COD4, is a first person shooter game, the first in the franchise to have its action set in modern days as opposed to the usual WWII setting. The game was developed by Infinity Ward and published by Activision. It was released on November 6, 2007. Below you will find a full collection of cheats and unlockables for Call of Duty 4: Modern Warfare for PlayStation 3.

Cheats:

Cheat mode available: Successfully complete the game. A “Cheat” option will now appear during game play at the “Options” menu.

Cheat options
You have to collect the intel pieces (enemy laptop computers) hidden throughout the game to unlock the cheat options. The number of pieces you have determines which specific cheats are available. Here are the options and number of intel needed:

CoD Noir: 2 Intel Pieces. Allows black and white graphics.
Photo-Negative: 4 Intel Pieces. Inverts the colors.
Super Contrast: 6 Intel Pieces. Increases the contrast.
Ragtime Warfare: 8 Intel Pieces. Silent movie mode.
Cluster Bombs: 10 Intel Pieces. When a frag grenade explodes, four more will explode in a cross-shaped pattern.
A Bad Year: 15 Intel Pieces. Enemies explode into tires when shot.
Slow-Mo Ability: 20 Intel Pieces. The game slows to half speed when you melee.
Infinite Ammo: 30 Intel Pieces. Reloads are no longer necessary. This has no effect on C4, Claymores, and Stinger missiles.

Unlockables:

Golden weapons
Golden Ak-47: Complete all Assault Rifle challenges.
Golden Desert Eagle: Reach level 55.
Golden M1014: Complete all Shotgun challenges.
Golden M60: Complete all LMG challenges.
Golden Mini-Uzi: Complete all SMG challenges.
Golden SVD: Complete all Sniper challenges.

Rank bonuses
Reach the indicated rank in multiplayer to unlock the corresponding bonus.

Private

Level 1: All starting equipment
Level 2: Demolitions Class Weapon Class
Level 3: Sniper Class Weapon Class

Lance Corporal

Level 4: Create a Class
Level 5: Gun Challenges
Level 6: New playlists

Corporal

Level 7: M21 Sniper Rifle
Level 8: Last Stand Perk Class 3
Level 9: Boot Camp Challenges 1

Sergeant

Level 10: M4 Carbine Assault Rifle
Level 11: UAV Jammer Perk Class 2
Level 12: Clan Tag

Staff Sergeant

Level 13: Mini Uzi Submachine Gun
Level 14: Bomb Squad Perk Class 1
Level 15: Boot Camp Challenges 2

Gunnery Sergeant

Level 16: M1911 Pistol
Level 17: Martyrdom Perk Class 2
Level 18: Boot Camp Challenges 3

Master Sergeant

Level 19: M60E4 Light Machine Gun
Level 20: Sleight of Hand Perk Class 2
Level 21: Operations Challenges

Master Gunnery Sergeant

Level 22: Dragunov Sniper Rifle
Level 23: Claymore Perk Class 1
Level 24: Operations Challenges 2

2nd Lieutenant

Level 25: G3 Assault Rifle
Level 26: Iron Lungs Perk Class 3
Level 27: Operations Challenges 3