Modifications to prince.exe (hex editing)

[poirot]

I'm reopening this thread so we can post new hacks.

I'm starting with level 1 events. I have to check if they are already implemented in princehack.xml.

Level 1 events:

Code: Select all

07e2:4b2d  a3 98 4c           mov    [4c98],ax
07e2:4b30  a3 f2 5f           mov    [5ff2],ax
07e2:4b33  83 3e 9e 0f 01     cmp    word ptr [0f9e],0001 <-- level where the kid starts crouching
07e2:4b38  75 22              jne    4b5c

Search for: a3 .. .. a3 .. .. 83 3e .. .. 01 75 22
(offsets are p0:0x4c2d, u0:0x62dd, p3:0x50b5, u3:0x57f5, p4:0x4b71, u4:0x5ca1)

and replace
01 for level where the kid starts crouching

Code: Select all

07e2:61cb  83 3e aa 4c 00     cmp    word ptr [4caa],0000
07e2:61d0  74 30              je     6202
07e2:61d2  83 3e 9e 0f 01     cmp    word ptr [0f9e],0001 <-- level where the kid music is played after loading
07e2:61d7  75 29              jne    6202
07e2:61d9  9a 99 72 79 0c     call   0c79:7299

Search for: 83 3e .. .. .. 74 .. 83 3e .. .. 01 75
(offsets are p0:0x62cb, u0:0x797b, p3:0x675f, u3:0x6e9f, p4:0x621b, u4:0x734b)

and replace
01 for level where the kid music is played after loading

---------------------

xml hacks are:

Code: Select all

<hack name="Hack name here">
	<offset file="p0" value="0x62cb"/>
	<offset file="u0" value="0x797b"/>
	<offset file="p3" value="0x675f"/>
	<offset file="u3" value="0x6e9f"/>
	<offset file="p4" value="0x621b"/>
	<offset file="u4" value="0x734b"/>

	<check codes="83 3e .. .. .. 74 .. 83 3e .. .."/>
	<read default="01" name="level where the kid music is played after loading" type=""/>
</hack>
<hack name="Hack name here">
	<offset file="p0" value="0x4c2d"/>
	<offset file="u0" value="0x62dd"/>
	<offset file="p3" value="0x50b5"/>
	<offset file="u3" value="0x57f5"/>
	<offset file="p4" value="0x4b71"/>
	<offset file="u4" value="0x5ca1"/>

	<check codes="a3 .. .. a3 .. .. 83 3e .. .."/>
	<read default="01" name="level where the kid starts crouching" type=""/>
</hack>

I'll take a look at the sword level too. Btw, I'm using a development version of CusAsm 2.0 that I'll put online asap.

[David]

We already have a topic with the same title: viewtopic.php?f=73&t=661

Having the sword at the beginning of the level:

Code: Select all

00004B25:i837E0601                       cmp (w)   [bp+06],+01
00004B29:i7405                           je        file:00004B30
00004B2B:iB80100                         mov       ax,0001
00004B2E:iEB02                           jmps      file:00004B32
00004B30:i2BC0                           sub       ax,ax
00004B32:iA3A234                         mov       [+34A2],ax

[bp+06] stores (temporarily) the number of the current level.
[+34A2] stores whether the prince has the sword (0=no, 1=yes)

search: 83 7E 06 01 74 05
change: This can be changed in many ways.
If you want that the prince has the sword on all levels except one, change 01 to the number of that level.
If you want that the prince never has the sword, change 74 to EB. (je->jmp)
If you want that the prince always has the sword, change 74 05 to 90 90. (je->nop)
If you want that the prince has the sword on level XX and all levels after that, change 01 to XX and 74 to 7C. (je->jl)

offsets:
u0: 0x61D5, u3: 0x56E5, u4: 0x5B91, p0: 0x4B25, p3: 0x4FA5, p4: 0x4A61


Also, I have been making a disassembly using IDA, and I thought I could upload it. It could be used to search hacks easier.

[Norbert]

[...], and I thought I could upload it.

Go for it.
Feel free to PM me anything if you want me to put it up at popot.org.

[David]

I have attached the disassembly to this post.
Of course it is far from being complete. All suggestions and corrections are welcome.

[yaqxsw]

I have attached the disassembly to this post.
Of course it is far from being complete. All suggestions and corrections are welcome.

that prince without sword all level? but i brought more time, guards LP too..

[Norbert]

that prince without sword all level?

Not yet, but we're getting closer.
Thanks for the upload David.

[Norbert]

yaqxsw, if you want I can provide you with a PRINCE.EXE file that will make the prince never have a sword (or only from a certain level, like from 11).
(I will use David's instructions to make the changes.)
If you want this, you can send me the PRINCE.EXE file you're using (from the CusPop export) via a private message and I'll send it back with the changes you want.
Or, alternatively, you could try to use a hex editor yourself (like wxHexEditor; wxHexEditor-v0.20-Win32.zip is for Windows).

[poirot]

Is it possible to ask for the source code to Lance Groody? Anybody wants to do that?

[Norbert]

Is it possible to ask for the source code to Lance Groody? Anybody wants to do that?

Would having the source code be an end by itself or a means to an end?
Either way, Groody, as a non-copyright holder, is not in a position to publish the code.
We'd have to ask Mechner to ask Groody, I think.
The code itself could be useful to find exploits/bugs, and could simplify making modifications.
Other than that, there are copyright/trademark problems, even with FreePrince.
Maybe we should let sleeping dogs lie, I don't know.

[yaqxsw]

yaqxsw, if you want I can provide you with a PRINCE.EXE file that will make the prince never have a sword (or only from a certain level, like from 11).
(I will use David's instructions to make the changes.)
If you want this, you can send me the PRINCE.EXE file you're using (from the CusPop export) via a private message and I'll send it back with the changes you want.
Or, alternatively, you could try to use a hex editor yourself (like wxHexEditor; wxHexEditor-v0.20-Win32.zip is for Windows).

I not programmist, and i can't try HexEditor.. but i sent you my Edit PRINCE.EXE

[yaqxsw]

yaqxsw, if you want I can provide you with a PRINCE.EXE file that will make the prince never have a sword (or only from a certain level, like from 11).
(I will use David's instructions to make the changes.)
If you want this, you can send me the PRINCE.EXE file you're using (from the CusPop export) via a private message and I'll send it back with the changes you want.
Or, alternatively, you could try to use a hex editor yourself (like wxHexEditor; wxHexEditor-v0.20-Win32.zip is for Windows).

How sent Prince.EXE? Message said, i cannot add some File.. i think, i can sent you in E-Mail or i write here my edit.

-----------------
300 minuts Time
Start level 1, Start LP 2

Maximal Prince LP 12

Guards LP
Level 1 - 3
Level 2 - 3

Level 4 - 4
Level 5 - 5
Level 6 - 6
Level 7 - 6
Level 8 - 6
Level 9 - 6
Level 10 - 6
Level 11 - 6
Level 12 - 6
Level 13 - 12

[Norbert]

How sent Prince.EXE?

If private messaging is not working, you can e-mail it to info@popot.org.

By the way, CusPop has a section "Customize allowed resources per level".
If you check everything there, you can use, for example, use the chomper in level 2.
It allows you to use (almost) all the resources everywhere and the screen will not get distorted.

[yaqxsw]

E-mail sent

[Norbert]

E-mail sent

Okay, I've made the change and I've sent you back the altered PRINCE.EXE file.

[yaqxsw]

Thank! ot functioniert!