Re: What tool debugs a miscalculated area of memory in a game program written in C?

Posted on 2024-04-17, 14:12

by

by llm

in Milliways

in Milliways

one of my projects were im using current clang to compile (not link - because its makes no sense due tos clangs absense of DOS support) a DOS MT32 driver code for Stunts: https://github.com/LowLevelMahn/UnifiedMT15/blob/main/drv.c see the empty stubs im using when compiling with #ifdef __clang__ im …

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Re: Looking for help with analyzing disassembled code->

Posted on 2024-04-16, 18:16

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by llm

in Milliways

in Milliways

Okay, so I have disassembled an MS-DOS old game (Cartooners) which was compiled using the Microsoft C 5.10 compiler. With some effort I managed to identify a few parts as a C functions for example: the CARTOONS.EXE is packed with EXEPACK https://www.bamsoftware.com/software/exepack/ - Win/Linux …

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Re: What tool debugs a miscalculated area of memory in a game program written in C?

Posted on 2024-04-16, 05:23

by

by llm

in Milliways

in Milliways

when i download the files it only contains masses of Ö chars - never got problems downloading any source files but my tip: always use recent compilers - even if not capable to build for DOS - im using latest LLVM/clang to compile my DOS stuff and find errors (by using #ifdef __clang__ disabling some …

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Re: What is the last version of IDA Pro to support 16 bit DOS executeables decompilation?

Posted on 2023-12-03, 19:23

by

by llm

in Marvin \ Software

in Marvin \ Software

Thanks for the comment and the link. I see, but somewhere on the internet I've read that IDA Pro Free ver. 4.3 will be OK for my purposes (just dissassembly is fine too), but I'm wondering if it's the last (newest) of 4.x versions? And I can't even find this free version 4.3 anywhere for download. …

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Re: DOSBox debugger

Posted on 2023-10-31, 07:58

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by llm

in DOSBox Development

in DOSBox Development

the BPM (breakpoint on memory change) feature seems not to work when using F10 (only with F5) - or do i use it the wrong way? long time dosbox debugger user but never used BPM before in src\platform\visualc\config.h #define C_DEBUG 1 #define C_HEAVY_DEBUG 1 in dosbox-SVN.conf [cpu] core = normal …

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Re: DOSBox debugger

Posted on 2023-09-22, 11:38

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by llm

in DOSBox Development

in DOSBox Development

Hi llm, Many thanks for your very useful reply. I know the basics of using IDA Pro and basics of Assembly language. And I also understand Mode 13h for VGA Graphics. How should I go about finding the Pixel Write code in IDA Pro, if DOSBox does what you say in terms of Code relocation ? the clean way …

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Re: DOSBox debugger

Posted on 2023-09-22, 05:02

by

by llm

in DOSBox Development

in DOSBox Development

I am trying to find In IDA Pro 5 the Assembly Code, For a Plane in a WW2 Dos 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 got the following output :- DEBUG: Memory breakpoint : A000:0000 - 9F -> 15 what does this …

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Re: I've developed a unpacker for CC0/CC1 game files - anyone know more games that i can test?

Posted on 2023-09-16, 16:42

by

by llm

in Marvin \ Software

in Marvin \ Software

nice i've found these file-journal thing in serveral other files Mystical North & South The-Light-Corridor Shufflepuck Cafe Cool Ball the file info is always 84 bytes - and enough examples to understand the missing header part 😀

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Re: I've developed a unpacker for CC0/CC1 game files - anyone know more games that i can test?

Posted on 2023-09-16, 07:25

by

by llm

in Marvin \ Software

in Marvin \ Software

I noticed you've found that unused bytes between data blocks can exist but decided to ignore it. Did you investigate but not see anything interesting? Or may some juicy bits still be hidden in there? I remember some titles having things like source code excerpts in their slack space... i've re- …

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Re: I've developed a unpacker for CC0/CC1 game files - anyone know more games that i can test?

Posted on 2023-09-15, 06:03

by

by llm

in Marvin \ Software

in Marvin \ Software

approved new games using that compression Disney's Beauty and the Beast: https://www.mobygames.com/game/46990/disneys-beauty-and-the-beast/, release 1992 on DOS Wild Life: https://www.mobygames.com/game/54191/wild-life/, release 1990 on DOS Murders in Venice: https://www.mobygames.com/game/4793/ …

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Re: I've developed a unpacker for CC0/CC1 game files - anyone know more games that i can test?

Posted on 2023-09-14, 20:38

by

by llm

in Marvin \ Software

in Marvin \ Software

Here we go: thank you for this bunch of new games to test :) PS would you by chance know the short assembly byte pattern to use so I can search if a game calls the old INT15 memory management mechanism to access memory above 1MB. I'm not sure what function is set before calling int15 they would use …

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Re: I've developed a unpacker for CC0/CC1 game files - anyone know more games that i can test?

Posted on 2023-09-13, 05:52

by

by llm

in Marvin \ Software

in Marvin \ Software

anyone here with some of these huge game collections around - especially games from 1988 to 1995? you can help me by seaching your game folders for parts of the compression code BF 01 03 mov di, 301h 33 C0 xor ax, ax F3 AB rep stosw 5F pop di 07 pop es all you need is to download the standalone …

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Re: I've developed a unpacker for CC0/CC1 game files - anyone know more games that i can test?

Posted on 2023-09-12, 18:49

by

by llm

in Marvin \ Software

in Marvin \ Software

I noticed you've found that unused bytes between data blocks can exist but decided to ignore it. Did you investigate but not see anything interesting? Or may some juicy bits still be hidden in there? I remember some titles having things like source code excerpts in their slack space... only tested …

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I've developed a unpacker for CC0/CC1 game files - anyone know more games that i can test?

Posted on 2023-09-12, 16:34

by

by llm

in Marvin \ Software

in Marvin \ Software

I've developed a unpacker for CC0/CC1 game files - mostly(or exclusivly?) used by games from Infogrames Europe SA released between 1989 and 1992 anyone know more games that i can test? i don't know if that compression was only used in that timespan or only by Infogrames Europe SA History: while …

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Re: DOS programming tools

Posted on 2023-07-08, 13:15

by

by llm

in Marvin \ Software

in Marvin \ Software

Open Watcom V2 (https://github.com/open-watcom/open-watcom-v2) is under active development and a fully DOS/Win16/OS2 able compile suite (with debugger etc.) but you can also cross build your DOS stuff with the Win64 or Linux variant (as i do) ->got a cross C and C++ compiler (wc,wcc), Linker (wlink) …

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Re: Is my disassembly EGA code understanding correct so far?

Posted on 2023-06-27, 12:57

by

by llm

in Marvin \ Video

in Marvin \ Video

thanks cinnabar wrote on 2023-06-26, 17:13: You might want a better EGA reference this mame source seems to be also helpfull to me: https://github.com/mamedev/mame/blob/master/s … bus/isa/ega.cpp and for the last line Copy code to clipboard 1 outb(0x3CE, 8); the the 0x3CF port still contains the …

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Is my disassembly EGA code understanding correct so far?

Posted on 2023-06-14, 18:59

by

by llm

in Marvin \ Video

in Marvin \ Video

this is disassembled from a game mov dx, 3C4h mov ax, 0F02h out dx, ax mov dl, 0CEh mov ax, 3 out dx, ax mov ax, 205h out dx, ax mov al, 8 out dx, al ported to C with some infos i've found https://fd.lod.bz/rbil/ports/other/p03c403c5.html 03C4 -W EGA TS index register https://fd.lod.bz/rbil/ports/ …

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Re: Pulling my hair out with EGA programming.

Posted on 2023-05-28, 11:01

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by llm

in Marvin \ Video

in Marvin \ Video

Lameguy64 wrote a small (Watcom C) program to test out EGA stuff, accessing 0xA000:0 directly like you want http://lameguy64.net/?page=dosstuff http://lameguy64.net/snippets/EGATEST.C compiled for me with: https://github.com/open-watcom/open-watcom-v2 without a problem

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Re: How will this affect DOSBox development?

Posted on 2023-05-21, 11:43

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by llm

in PC Emulation

in PC Emulation

sliderider wrote on 2023-05-21, 07:06: or am I assessing this incorrectly? dosbox does not rely on any hardware features - its a full blown software-emulation of the old hardware, so recompiling of dosbox itself would be enough

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Re: DOSBox debugger

Posted on 2023-05-04, 06:42

by

by llm

in DOSBox Development

in DOSBox Development

i also always got trouble easily finding the output files - so i just added a fixed path to all my needed output files memdump, cpulog etc. - maybe also a solution for you or a way to check if the file isn't generated at all (for whatever reason)

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