The Building Blocks

NASM syntax is straightforward but strict. Each instruction follows a specific format, and understanding data types is essential for writing correct code.

• Labels: Used to mark locations in code (like bookmarks).
• Instructions: Tell the CPU what to do, like mov, add, or jmp.
• Operands: The data or registers operated on.

Common Data Types

• db (define byte): 8 bits
• dw (define word): 16 bits
• dd (define double word): 32 bits
• dq (define quad word): 64 bits

Example:

section .data
  myByte db 42
  myWord dw 1234
  myDword dd 100000
  myQword dq 1234567890123456

Comments Make Code Clear

Use ; for comments in NASM:

mov eax, 1 ; this loads 1 into eax

Real-World Value

Clean syntax and understanding of data types help you avoid bugs and make your programs work as expected.