Legend

This page and the pages linkied here contain the full list of important memory addresses that you will want to edit to modify the game.
For an instruction on how to use HxD, please visit this page.

1. All the hexadecimal values, shown on this page, will have prefix $ for clarity.
2. All the hexadecimal values, which are addresses in HxD, will have prefix @. To get an address in Cheat Engine, add $400000 to it.
3. Names of the registers, instructions and such will be written in ALL CAPS.
4. Since that OG Plants vs Zombies release is a 32-bit executable, the maximum capacity of the registers will be 32-bit.
5. The pages are divided into the following topics:

1. General
2. Seed packets
3. Levels
4. Plants
5. Zombies

To navigate trough the pages, refer to the color coding of each topic.

AND ALSO: BEFORE MAKING ANY CHANGES TO THE GAME, HIGHLY CONSIDER MAKING A BACKUP. EVEN BETTER, MAKE A BACKUP BEFORE EVERY CHANGE YOU MAKE.

List of Speed Packets

In the source code, as evidenced by decompilation, information about the plants' seed packets is stored in constant array of structures that includes the 50 plants that are unlocked in adventure mode and shop + unobainable plants. This array is located at address @29F2B0 and each element of it takes $24 bytes, so for the ease of use, set HxD alignment to 36.

Day:
@29F2B0 - Peashooter
@29F2D4 - Sunflower
@29F2F8 - Cherry Bomb
@29F31C - Wall Nut
@29F340 - Potato Mine
@29F364 - Snow Pea
@29F388 - Chomper
@29F3AC - Repeater

Night:
@29F3D0 - Puff Shroom
@29F3F4 - Sun Shroom
@29F418 - Fume Shroom
@29F43C - Grave Buster
@29F460 - Hypno Shroom
@29F484 - Scaredy Shroom
@29F4A8 - Ice Shroom
@29F4CC - Doom Shroom

Pool:
@29F4F0 - Lily Pad
@29F514 - Squash
@29F538 - Threepeater
@29F55C - Tangle Kelp
@29F580 - Jalapenio
@29F5A4 - Spikeweed
@29F5C8 - Torchwood
@29F5EC - Tall Nut

Fog:
@29F610 - Sea Shroom
@29F634 - Plantern
@29F658 - Cactus
@29F67C - Blover
@29F6A0 - Split Pea
@29F6C4 - Starfruit
@29F6E8 - Pumpkin
@29F70C - Magnet Shroom

Roof:
@29F730 - Cabbage Pult
@29F754 - Flower Pot
@29F778 - Kernel Pult
@29F79C - Coffee Bean
@29F7C0 - Garlic
@29F7E4 - Umbrella Leaf
@29F808 - Marigold
@29F82C - Melon Pult

Upgrades:
@29F850 - Galting Pea
@29F874 - Twin Sunflower
@29F898 - Gloom Shroom
@29F8BC - Cattail
@29F8E0 - Winter Melon
@29F904 - Gold Magnet
@29F928 - Spikerock
@29F94C - Cob Cannon
@29F970 - Imitater

Unobtainable:
@29F994 - Explode O Nut
@29F9B8 - Ball Nut
@29F9DC - Sprout
@29FA00 - Reverse Repeater

Seed Packet Properties

Each element has the following 9 propeties (4 bytes each) (number is the offset from the entry address):

$00 - Seed ID

Defines what what seed packet spawns this plant, altough changing it doesn't affect much.
For more information on Seed IDs, look at the image below

$04 - Scrapped field, changing it doesn't affect anything
$08 - Reanim ID

Defines what type of animation this plant uses.

$0C - Unknown value
$10 - Sun cost
$14 - Recharge time (in 100th of a second)
$18 - Subclass

If anything other than zero, then plant is a shooter.

$1C - Action rate (in 100th of a second)
$20 - Unknown value