8086 Assembly Debugging with AFD - Advance Full Screen Debug [PART 2 - Advance]

In the last tutorial we have covered some basic features of AFD  to get you started . Lets look at some advance features that will make debugging 16 bit assembly programs less painful.

This image is from last tutorial in which we divided the AFD display into four regions.
1- Registers
2- Disassembly
3 & 4 - Memory Window 1 & 2

The features are explained with examples ( where necessary ) below.

Navigation 

The very first thing that I will write about is how to change content of these regions without typing a command in CMD.

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.

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

1- NASM

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