This article will define three key types of registers in the x86 architecture and then go on to show simulations of registers’ contents after specific instructions have been run.

This article is designed for self-starters, students and professionals who want to gain a detailed understanding of the x86 hardware architecture, including its internal architecture with emphasis on registers. This article will help to give you the fine details and better understanding of architecture issues, particularly in processor registers.

Figure 1: Internal architecture of a computer using x86 hardware


Fundamental components of a computer system

The fundamental components of a computer system are:

  1. The Central Processing Unit (CPU), which includes the control unit, arithmetic logic unit (ALU) and registers
  2. Random Access Memory (RAM)
  3. Input and output peripherals, which include mouse, keyboard and disk drive
  4. The system bus, which consists of the data bus, control bus and address bus

The Central Processing Unit (CPU)

Writing at Digital Trends, Jon Martindale defined a CPU as follows: “A central processor, or CPU, is arguably the most important component of any computing device. It handles basic instructions and allocates the more complicated tasks to other specific chips to get them to do what they do best.”

CPU Registers

TechDifferences defined registers as follows: “Registers are the smallest data holding elements that are built into the processor’s hardware itself. Registers are the temporary storage locations that are directly accessible by the processor. The registers hold the instruction or operands that is currently being accessed by the CPU.”

General Purpose Registers (GPRs)

The x86 architecture contains eight 32-bit General Purpose Registers (GPRs). These registers are mainly used to perform address calculations, arithmetic and logical calculations. Four of the GPRs can be treated as a 32-bit quantity, a 16-bit quantity or as two 8-bit (Read more...)

*** This is a Security Bloggers Network syndicated blog from Infosec Resources authored by Richard Azu. Read the original post at:

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Richard Azu

Richard has over 16 years of experience in Network/Telecom Engineering. Experienced in the deployment of voice and data over the 3 media; radio, copper and fibre, Richard – a system support technician currently with First National Bank Ghana Limited is still looking for ways to derive benefit from the WDM technology in Optics. Using Kali as a springboard, he has developed an interest in digital forensics and penetration testing.

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