Introduction to Computer Hardware

  • Information technology is a collective term used to describe the use of a computer to process and display data.
  • A computer needs two components to be functional – the hardware and the software. Obviously, the electric power must be provided via the Power Supply Unit (PSU) that powers the motherboard and all internal hardware, as well as external peripherals, including the output hardware (e.g monitor and printer) and input hardware (e.g keyboard and mouse).
  • Hardware is a collective term used to designate the physical parts of the computer.
  • Software are the programs and applications that run on the hardware, and are responsible for processing data.
  • Hardware allows for data input and output, while software allows for data processing.
  • The computer case houses the internal hardware and anything outside it, e.g keyboard and mouse, is called a peripheral. The peripheral is connected to the mainboard by a cable or wirelessly through Bluetooth or WiFi (wireless fidelity) technology. The internal hardware is built around a main circuit board called the motherboard. They are designated as internal hardware because they are inside the computer case, and they are plugged (or installed) directly onto dedicated sockets and slots built in the motherboard.
  • The 3 key computer hardware are the central processing unit (CPU), main memory provided by the random-access memory (RAM), and the secondary non-volatile memory provided by the storage disk such as a mechanical hard disk/drive (HDD) or a solid-state drive (SSD).
  • The most basic software needed for a computer to become functional is called the operating system (OS). The OS provides an interface that allows OS-dependent software called programs to interact with the hardware and process data. The two main functions of the OS are abstraction and arbitration. Abstraction and arbitration are best described as services rendered to the end user, and they are described hereafter:
  1. Abstraction: The OS conceals the hardware configuration details from the user application so that these applications – which are usually written in high-level programming languages – do not need to be tailored (or written) for each possible hardware configuration.
  2. Arbitration: The OS manages the access of user applications to hardware resources, so that 2 or more applications running simultaneously can share the same hardware resources. The main shared hardware resources are the CPU, RAM, Input and Output (I/O) devices (including the Network Interface Card [NIC]), and PSU.
  • RAM provides the working space where software data and instructions are placed (or hosted) before they are executed (or processed) by the CPU.
  • If the RAM needs to be refreshed when working so that it can load data into the CPU, then it is called dynamic RAM (DRAM); but if it does not need constant refreshing during operations, then it is a static RAM (SRAM). Usually, SRAM is used to store cache memory, and is normally fitted in the motherboard. Meanwhile, DRAM is used as system RAM which is plugged into RAM slots in the motherboard.
  • RAM speed is calculated in megaHertz (MHz).
  • There are currently 4 types of DRAM: DDR (has 184 pins), DDR2 (has 240 pins), DDR3 (has 240 pins), and DDR4 (has 288 pins).
  • Laptop DRAM is physically smaller than the DRAM used in a desktop personal computer (PC), and it is called the SO-DIMM (which stands for Small Outline Dual In-line Memory Module). DDR3 SO-DIMM has 204 pins and DDR4 SO-DIMM has 260 pins.
  • HDD is analogous to a filing cabinet where one stores documents and paperwork. It serves as the non-volatile or permanent memory in the PC. It is the secondary (non-volatile) storage in the PC.
  • To run a program, it first needs to be moved from the HDD to RAM in readiness for data processing by the CPU. HDD is connected to the motherboard via a Serial Advanced Technology Attachment (SATA) connection, and it spins at 5400 revolutions-per-minute (rpm), 7200rpm, or 10000rpm.
  • SSD has a much higher data transfer rate (DTR) than the HDD.
  • Others devices can serve as secondary storage devices, e.g floppy discs, optical discs, flash drives, and memory cards.
  • An optical drive allows for data stored in optical discs such as CDs and DVDs to be read, and in some instance allows for data to be written into a compatible optical disc through a process called burning.
  • Memory cards are also called SD cards. They come in 3 formats: SD card that measures 32.0 millimeters (mm) by 24mm, mini-SD that is 21.5mm by 20mm, and the micro-SD that is 15mm by 11mm. The memory card is read by a card reader, which is usually built into a smartphone, laptop, or tablet.
  • The USB flash drive is also called a memory stick, and it plugs into the universal serial bus (USB) port of the computer.
  • A hard disk that is not plugged into the SATA port of the motherboard, but is instead plugged into the USB port is called an external hard disk.
Assorted secondary storage devices (from left): mechanical HDD for desktop PC, mechanical HDD for laptop PC, external hard drive.
  • If the hard drive is connected to the PC through the Ethernet port, then it is called a network attached storage (NAS) drive. The NAS drive must be installed in a NAS unit that has its own dedicated power supply, processor, and RAM. The NAS drive allows for backup storage.
  • If this NAS drive is linked to an online storage that can be accessed via the internet, then files can be uploaded to, and downloaded from, the online storage. This type of online storage is called a personal cloud. The personal cloud can provide more storage space than that found in the NAS drive, though one must usually pay for the storage space provided in the cloud storage. If the personal cloud allows for automatic updating of data in a folder in the cloud when the same folder is updated in the NAS drive, then the folders are described as being synced and the automatic updating process is called syncing.
  • NB: Syncing can only occur when an internet connection allows for data transfer from the NAS drive to the personal cloud.
  • The main providers of personal cloud services are Western Digital through its service, Google via its service, Dropbox via its service, and Microsoft through its service.

Leave a comment

Your email address will not be published. Required fields are marked *