![]() ![]() How should I go about finding the Pixel Write code in IDA Pro, if DOSBox does what you say in terms of Code relocation ?ġ. ![]() And I also understand Mode 13h for VGA Graphics. I know the basics of using IDA Pro and basics of Assembly language. Use UNP: Reply 156 of 159, by eddywinch82 So the question is: what is your assembler, 16bit coding, IDA Pro/Ghidra background - because that knowledge is very needed to understand even the tiniest part of the codeĪnother problem is getting the point of code in IDA when finding code in the Dosbox debugger - the IDA output is not relocated but the code inside Dosbox isĪnd another thing: do you know that the SWOTL.EXE is LZEXE compressed - so if you look at the code in IDA, without uncompressing it first you will just see the decompression code for the exe itself? Normally there a some functions above this call that are relevant its a write to A000:0000 and the value 9F gets replaced with 15 - so some code is changing the color of pixel 0,0īut beware: its very unlikely that the code behind that pixel write is directly some function that draws planes - if will be just a pixel-set/or texture set routine that is used for every drawing in the game That is the first thing that is absolutely needed to understand what the debugger gives you back and how to read the code behindģ. do you know how mode 13h, 320x200 at 256 colors is programmed/working? this is the Dosbox - not Dosbox X - forum - but the feature set is similar - but go to the Dosbox X webpage to discuss bugs you eventual findĢ. what does 9F -> 15 mean ?Īny help and info would be much appreciated. I have allready looked for A000h in IDA Pro, but what should I interpret from that DEBUG line i.e. exe File Decompiled what should I search for ? I got the following output :- DEBUG: Memory breakpoint : A000:0000 - 9F -> 15 what does this output mean ? In IDA Pro 5 with the game. I typed the bpm A000:0 in Dosbox X Debugger and then ran the game and changed to a view showing the Plane in Question. I am trying to find In IDA Pro 5 the Assembly Code, For a Plane in a WW2 Dos Game. It will be likely that related functions will be next to each other, so once you've looked into the given identified function, you may also be able to review previous or following functions to see if they have identifiable graphic routines." Using the previously discussed techniques, you can find the same place in your IDA disassembly, and look into reversing that method first. Then whichever routine modifies it first will trigger the breakpoint. So you could do 'bpm A000:0' to set a breakpoint on the first byte of the screen memory (i.e. It has a use command called 'bpm' that allow you to set a memory breakpoint, which then gets triggered if the given memory address changes. The other alternative is to use the DosBox Debugger. Since this is the area of memory that graphics are commonly displayed in, it can be a quick way to locate graphic routines. ![]() The first is to entirely use IDA, and simply search for immediate values of 'A000h'. "For finding the graphic routines you have two options: On a Reverse Engineering Website, I read the following :. Sorry to be a nuisance I'd check the source and do further testing if this wasn't on subversion □ Reply 149 of 159, by ripsaw8080 For now I have to use DOSBox-X because the binary I'm working with is packed, so I need to dump out the unpacked segments. Perhaps also add to the DEBUG message, "Wrote file to: ". The file creation is likely failing, and although I haven't looked at the source - I'm certain there are probably some additional checks to verify the file was created, written, and closed correctly. Just to reiterate, I've done full system scans for the files in case I missed obviously places where the memdumpbin/memdump would put the files. My mount is in C:\dosprogs, DOSBox-X runs out of my user Downloads folder, DOSBox runs out of C:\Program Files, that's why I thought maybe its a permissions issue. Again for some reason this works with DOSBox-X and not regular DOSBox. I just tested again by running as an admin. What is the current directory in your case? I wouldn't think so, but then I'd also think the file is being created.
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