Best debugger for DOS?

Trying to remove protection from an old DOS game I have, 'The Jetsons The Computer Game'. Trying to find a good debugger I can step through with. I can't step with IDA Pro, debug.exe is quite confusing.

First it checks the disk for certain sectors, however it is very easy to do a n00bish JMP over all of that then the game will load a COM file into memory and wait for that to terminate (and get its exit code). I can also directly launch that COM file (CMF extension). Both give the same result. JMP'ing over the floppy check might not be the way to go?

By the way, is the CMF extension a relic of any known copy protection during the DOS era?

Even if this game is cracked already, I'd really like to get this one myself.

[henry_y]

Have you try SuperTracer a.k.a TR?
It's similar to SoftIce.
If the Game is running on Protected Mode, I think you can use Windows version of TR (TRW). TRW can only run under Win9x.

Originally Posted by henry_y

Have you try SuperTracer a.k.a TR?
It's similar to SoftIce.
If the Game is running on Protected Mode, I think you can use Windows version of TR (TRW). TRW can only run under Win9x.

Thanks, I'll try that and Win9x version of SoftIce (forgot about it).

[infern0]

for real mode application there was AFD debugger. Also TD from borland (td386)

[SaNX]

Best debugger was DeGlucker, try to find it.

[dave_omirora]

I use the Syser Kernel Debugger v1.99.1900.1185 at my windows xp sp3, When run the programe my system is crash and Restart.

Any Idea about it?

I have Intel DG35EC mother board, Process core2 due 3.0Ghz, Ram 2 GB.

[SaNX]

Problem in a syser's driver, I think. May be in another driver May be you have antifirus, and it's conflict with syser.

[dave_omirora]

I use the Kaspersky 11.0.1.400

[SaNX]

Originally Posted by dave_omirora

I use the Kaspersky 11.0.1.400

it's answer for your question

[ZeNiX]

You have to be sure the data read from floppy.
If it is just checks, you can nop them.
But be careful that some copy-protection will read the sectors as part of executing codes.

I already forget the extension of .CMF. But maybe it is a copy protection from Taiwan over 10 years ago.

[o_o]

At the time i used a lot TR, TD and CUP386.
They were great

[progopis]

We are going support debuging DOS apps in the our OpenDbg, but I can not promise a quick release.

[sendersu]

Taitch,
have you tried DosBox?
although it is a DOS emulator, it has a very nice integrated debugger! (Soft-Ice like)

http://www.dosbox.com/

[henry_y]

Originally Posted by progopis

We are going support debuging DOS apps in the our OpenDbg, but I can not promise a quick release.

Wow, I'll be looking for this. I hope it will be good.