Saturday, 21 September 2013

8086 Assembly Debugging with AFD - Advance Full Screen Debug [PART 1 - BASIC]

As most of modern debuggers like IDA, Oledbg and Windbg seems to fail in debugging old 16 bit COM files.  I began researching on different debuggers available today to debug those 16 bit executables ( I am refering to COM files here )

While, doing my research I found a list of debuggers that are available these days to debug 8086 programs. Some of them are listed below

  • TR      -  ( no official link available + shareware)
  • grdb    -  Kind of an enhanced version of debug.exe ( discontinued after Windows XP )
  • Insight - The one with the most user friendly interface

There was another debugger that I couldn't find on the internet and that I used when I wrote my first 8086 assembly program in my university. It is Advance Full Screen Debug a.k.a AFD.

Saturday, 14 September 2013

Setting up AFD, NASM and DOSBOX for 8086 assembly ( Step By Step )


Download NASM ( Click on this link ) and install it.

Now open the cmd and change your directory to the installation folder using these instructions
> C:
> cd C:/tutorial/NASM
First instruction is for changing the drive to C if you are in any other drive.
Second instruction is to change current directory to our installation directory. In my case I have installed nasm in "tutorial" folder of C drive.
Now you will have to put all your ASM files in this folder to assemble/compile them .

Alternatively, you can just go to the installation directory through WINDOWS EXPLORER and click/run "nasmpath.bat" file . This will setup path ( skipping everything we discussed above ) and open a new console/cmd/command prompt for you.
Now you can run nasm from anywhere in the cmd. but you will have to be in the directory where your code files are placed.

2- AFD

Now download AFD  and copy it to the installation folder i.e. where your nasm is installed