Hi friends,

i had just think for cracking some dos program. but i dont know from where to start. bpx ***** dont work with it.
do i need any other tool than W32DASM and softice. please help me.


thanx

DOS works on INTs

Windows works on APIs

You get the idea.

To crack DOS, study INTs. Go go google and search for:

+"Ralf Brown" +"interrupt list"

The most comprehensive ever.

Try using Sourcer 7 (freely available on all major toolz site) and try using that.

Wdasm8.93 works OK for DOS programs. And yes, boot into DOS directly (bad luck if you are on NT or above) and run Softice for DOS.

...Have Phun

I've merged the above two posts to one single thread

Hello dipeshrestha !

When debugging DOS programs, you must use DLDR.EXE to load them into SoftICE (located in UTIL16 under SoftICE directory). Turbo Debugger is also nice (better) for DOS cracking. SoftICE for DOS makes some trouble (http://www.woodmann.net/forum/showthread.php?threadid=2106) under DOS >6.22. I don't know about CodeView, Microsoft's DOS debugger, I've never seen it. IDA works fine on DOS programs, W32Dasm a bit strange (some work, some not). Sourcer might be good, but I've never used it.

I would suggest using SoftICE for Windows with DLDR to load and debug the program and IDA to disassemble.

thanx DakienDX for ur valuable suggestion but where can i find the dldr.exe for softice i dont have that stuff in my machine. so pls help me.

Also give me help to find good essay on cracking dos application.

thank you

Hello dipeshrestha !

DLDR.EXE is located in the UTIL16 directory under the SoftICE installation directory. If not you've probably forget to install it and you have to remove SoftICE and reinstall it.

I can't give you any special tutorials for DOS since DOS programs have nearly no rules what they are allowed to do. DOS programs usually check (if they do) very often if SoftICE is loaded. Don't trace into BIOS area too much. Study INTs as aimless said. Nothing more to tell. Just try it.

If you don't rename DLDR.EXE it you can even use it with ICEDump. It's syntax is self-explaining when you execute it. (you must be on DOS command line)

Hi DakienDX,
Thanx for ur valuable suggestion. i will now try for it. if i face some problem i will ask for u . is that be OK.

dipeshrestha

Hi,
This might help..
Search google for Buckaroo Banzai tuts..
Also read ORC tuts..
regards
riPPadoGG