How to de-com a dos com file
 

I have a com file for DOS.

Is there a way to de-com it?

Pls offer your brain juice for the above qns.

*off-topic*

I am trying to find out because I have a dos machine. It will run a program. If some how it exits, a com file will run to reboot and with a countdown timer for user intervention. The thing is, if the countdown .com file is run before the program, the countdown time will run/countdown. But if the program is run first, then the countdown time will NOT run/countdown.

I have absolutely no idea why, so I am trying to find out how the .com does the countdown, then from there find out what is wrong.

*off topic*

or why wait commond is unable to countdown

ho de-com a dos com file
 

What do you mean by de-com
The most normal files in dos are 1) sys.com = system file without this dos don,t boot
2) Autoexec.bat = auto startup
3) Config.sys = system config
4) exe files =
5) devices drivers


So what is decom


good luck

it's very hard...com files run in real mode, live inside a single segment and have no relocation.
If you use 'ndisasm' (found as tool inside the 'nasm' assembler distribution) you can
de-assemble the small amount of code of your file and try to read/rewrite it.

What you are looking for is a disassembler. Which basically means any debugger.

ronlau9: .com are dos (small) executables. Only tiny memory model, iirc. None of that new fangled .exe stuff... ;)

I can think that the calling program is not really calling your countdown program when it exits. So one way is to bundle them in a batch file like so.
Calling.exe
Countdon.com

This wil tell you clearly what is the problem.
End

how to de-com a dos com file
 

O I know what a com file is I was one the old people who did programming under dos in fortran, Pascal, C in basic After that we get more power full
machines we use Cobol But that were the old days


best wishes

Believe it or not, COBOL still does most of the "heavy lifting" in the business world... and FORTRAN is still the language of choice in the scientific community. :)

Yeah, the company I work for still does a lot of COBOL. I'm fortunate enough to be in another department, though.