Learn ASSEMBLY with Real Code Examples

Assembly is hardware-specific and provides a human-readable representation of machine code.

It is used to optimize performance, interact directly with hardware, or for embedded systems programming.

Requires knowledge of CPU architecture, memory management, and instruction sets.

CPU instructions (mov, add, sub, jump, etc.)

Registers for temporary storage

Memory addressing modes

Macros for repetitive tasks

Conditional and unconditional branching

Registers and memory

Instructions and operands

Stack and calling conventions

Jump and loop instructions

Interrupts and system calls

source.asm

header files (if macros used)

linked object files (.obj/.o)

final executable

optional include directories

Write .asm file with instructions

Assemble with assembler (e.g., nasm -f elf64 file.asm)

Link object file to create executable

Run executable on target CPU

Debug with emulator or hardware debugger

Beginner: simple arithmetic routines

Intermediate: function calls and loops

Advanced: OS-level programming, interrupt handling

Expert: reverse engineering, malware analysis

Lower-level than C/C++

More precise than high-level languages

Hardware-specific vs portable languages

Faster execution for critical routines

Harder to maintain than modern languages

1950s – First assembly languages for early computers

1978 – x86 Assembly (Intel 8086)

1985 – MASM advanced support

1980s–1990s – ARM Assembly

2000s–2025 – Modern x86-64, ARM64 assembly in embedded and OS dev

Register: small, fast storage in CPU

Opcode: operation code

Label: named position in code

Assembler: converts assembly to machine code

Interrupt: CPU signal for handling events