MASM 6.1x comes with two essential tools: ml.exe and link.exe. ml.exe is the assembler. It takes in the assembly source code (.asm) and produces an object file (.obj) . An object file is an intermediate file between the source code and the executable file. It needs some address fixups which are the services provided by link.exe. Link.exe makes an object file into an executable file by several means such as adding the codes from other modules to the object files or providing the address f...
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This article will describe how to program VGA graphics Mode 13h using assembly language. Mode 13h is the 320x200x256 graphics mode, and is fast and very convenient from a programmer's perspective. The video buffer begins at address A000:0000 and ends at address A000:F9FF. This means the buffer is 64000 bytes long and that each pixel in mode 13h is represented by one byte.

One of the benefits of coding in assembly language is that you have the option to be as tricky as you like: the binary gymnastics of viral code demonstrate this above all else. One of the viral "tricks" that has made its way into standard protection schemes is SMC: self-modifying code.

In this article I will not be discussing polymorphic viruses or mutation engines; I will not go into any specific software protection scheme, or cover any anti-debugger/anti-disassembler tric...
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This article gives a short overview over two ways to go Ring0 in Windows 9x in an undocumented way, exploiting the fact that none of the important system tables in Win9x are on pages which are protected from low-privilege access.

A basic knowledge of Protected Mode and OS Internals are required, refer to your Assembly Book for that :-) The techniques presented here are in no way a good/clean way to get to a higher privilege level, but since they require only a minimal coding effort, ...
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We will create a fully functional Windows program that displays a message box saying "Win32 assembly is great!".

Windows prepares a wealth of resources for use by Windows programs. Central to this is the Windows API (Application Programming Interface). Windows API is a huge collection of very useful functions that resides in Windows itself, ready to be used by any Windows programs.

Essentially this article is an excuse to combine two of my favorite coding interests: the Linux operating system and assembly language programming. Both of these need (or should need) no introduction; like Win32 assembly, Linux assembly runs in 32-bit protected mode...however it has the distinct advantage of allowing you to call the C standard library functions as well as any of the usual Linux "shared" library functions. I have begun with a brief introduction on compiling asse...
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ATTENTION I:
This is based on Borland's C++ 4.02. Whenever possible I've checked it with any other library / program containing the specific functions, but differences may exist between this and your version of C. Also this is strictly 32-bit code, Windows compiler. No DOS or UNIX.]

ATTENTION II:
Size comparisons are extremely easy to do. Speed comparison's aren't. The differences in speed I give are based on RDTSC timings, but they DON'T take into account extr...
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