thanks for your suggestions. I tried objdump before...

but objdump dsiassembles the .obj file/ exe file generated by some well-known pascal compilers, the disassembled code is super long, and not human readable(unless to the developers of that particular compiler).
Thanks again for looking into the situation. I guess this is not the sort of programming issues that can be solved on top of someone's head. I will bypass it for now, and come back to it later on.