Cheat Engine

Kremnari · Newbie cheater Reputation: 0 Joined: 25 Oct 2007 Posts: 20

Yes, I know there is an unlimited money cheat out (thank you geri). This is more for a learning experience.

Background: The money comes from two sources; a simple turn based income (which I have found the value for) and a tile based generation (# of tiles * 2).

Goal: I want to find the "*2" instruction and be able to modify the "*2"

Thought process: I have located both the current money total and the turn based income. My thought was that between the two I could locate an instruction that would add the turn based and tile based values together then add them to the total.

I was unable to track the flow between the two.

I do know some assembly, but apparently not enough.

I have CE 5.6.1 and IDA Pro 5.5 with Hexrays 1.1

Any help (direction) would be greatly appreciated.
Kremnari

Geri · Moderator Reputation: 111 Joined: 05 Feb 2010 Posts: 5627

What You are trying to figure out is actually pretty hard in this game due to the coding of the program. If You still want to give it a go, I definitely advise to use CE 6 (even though it is in beta stage), because the debugger is more stable with this game with CE 6.

As for tracing back the code, You will have a hard time. The code which is reading the money is used very frequently. And both the reading and writing code is part of a small function that is only a few lines of codes. It will not be easy to trace it backwards, I am sure that the code is full of calls.

EDIT:
Maybe You can try to check "how many tiles are harvested" or "how much money do You get from harvesting". I don't know if they are saved on some memory address or calculated "on the fly" and appearing on a temporary address only. I would suggest to use a manual breakpoint on the code which is writing to the money and when You get cash at the start of the level, the game will stop. In this state, while the game is freezed, try to search for the values that I have mentioned. It may happen that You will find some temporary values only which will be thrown out a second later if You continue the game, but it may still be useful.

Kremnari · Newbie cheater Reputation: 0 Joined: 25 Oct 2007 Posts: 20

Thank you Geri! This was enough information that I was able to find what I was looking for.

Goto address 00401B4B, this points to the "02" (in a stack?) that is added each time a harvested tile is processed. I can change this to

Geri · Moderator Reputation: 111 Joined: 05 Feb 2010 Posts: 5627

00401B4B is probably a read-only static address. You could make a script which is changing this value, or just add it as a value to a table/trainer which can be changed, but that would probably mean that it would change for the enemy too.
As to make a player-sided cheat, I didn't look into this kind of cheat, but if You check my CE table, You see what did I use as player ID for the money.