Cheat Engine

imposible · Newbie cheater Reputation: 0 Joined: 12 Jan 2015 Posts: 22

I have a boolean [byte] variable stored at 0E99C4B4

I used "Find out what accesses this address", and found that on some event ( the player gets near a door) it is accessed by this instruction:

01494D63 - 80 7E 0C 01 - cmp byte ptr [esi+0C],01

which the disassembler shows as:

AI.exe+1B4D23 - 80 7E 0C 00 - cmp byte ptr [esi+0C],00

I interpret that

- The address of AI.exe+1B4D23=01494D63

- 80 7E 0C 01 is the binary code there
That code disassembled is cmp byte ptr [esi+0C],00

-That instruction compares zero with the value of a byte, located at the address ESI+0x0C

First problem: In the window before the disassembler the comparison was not with zero, but with one

Second problem: I need to breakpoint here, when it accesses my variable (located at 0E99C4B4)
So, I changed the breakpoint condition to ESI==0xE99C4A8=0E99C4B4-0xC

but, after I make that breakpoint, it never breaks. The window which detects who accesses 0E99C4B4 stop detecting accesses, but the variable value changes.

Dark Byte · Posted: Thu Jan 15, 2015 5:10 pm Post subject:

you're mixing things up, or are looking at the wrong instruction (AI.exe has to end with 0000 , so the ai.exe notation should have ended with a +xxx4d63)

most likely, AI.exe+1B4D63

i think you are looking at the last entry in the list, which is d23

As for the breakpoint condition, did you place a space between e99 and c4a8 ? If so, that will cause the check to always fail. (do not separate addresses with spaces, segments do not exist anymore)

imposible · Newbie cheater Reputation: 0 Joined: 12 Jan 2015 Posts: 22

Dark Byte · Posted: Thu Jan 15, 2015 5:43 pm Post subject:

it might be a bug, or all debug registers where used up in the thread that matters
Try handling it as a 4 byte while debugging (perhaps 1 byte might have an issue). As the video shows only that one byte changed, so a bigger net might get it.

Alternatively, you found a shared memory page, and the actual change was made in a different location (same physical address, different virtual address)

One thing to help with ce bugs is open the memoryview->debug->debug events and check that (it will show breakpoints hit, including those CE might have discarded)

oh yes, one feature that can be of use to you:
Go to AI.exe+1B4D63 in the code (what will always be the same) and then use the "find addresses this code accesses"
it may make finding the door position easier

imposible · Newbie cheater Reputation: 0 Joined: 12 Jan 2015 Posts: 22

Dark Byte · Posted: Thu Jan 15, 2015 6:10 pm Post subject:

imposible · Newbie cheater Reputation: 0 Joined: 12 Jan 2015 Posts: 22

Dark Byte · Posted: Thu Jan 15, 2015 7:10 pm Post subject:

ok, when you say you use dbvm I assume you use debugger interface dbvm
as far as I know, dbvm shouldn't be needed for alien, veh should suffice.

dbvm is only useful if you wish to use ultimap(or play with hardware level things), but it's not recommended as debugger interface if there are other debuggers that can be used.

and yeah, there's a bug in the dbvm interface where it won't handle breakpoints if they are not the very first breakpoint set since reboot

imposible · Newbie cheater Reputation: 0 Joined: 12 Jan 2015 Posts: 22

Dark Byte · Posted: Thu Jan 15, 2015 7:21 pm Post subject:

if you open the about form it'll tell you if it's running. (it'll tell you the version)
One easy way to disable it is to put your computer into stand by and then wake it up. It'll be gone (make sure you close ce before doing that)

the main thing though is to make sure the debugger interface is set correctly (veh debug, dbvm can be glitchy at times and is a last resort)