Chapter 1 - PC Hardware Study Guide

Monitor and Display Technologies

Light-emitting diode (LED) technology represents a specific classification of LCD display that utilizes specialized backlighting to achieve several performance advantages. LED panels are characterized by lower power consumption than standard LCD backlighting systems. Physically, these displays are thinner and lighter while providing superior brightness and enhanced contrast compared to traditional LCD panels.

Liquid crystal display (LCD) technology operates through the use of two polarizing filters with a liquid crystal solution sandwiched between them. The display functions by applying an electronic current to align the crystals, which dictates whether light is permitted to pass through or is blocked. This modulation of light is what creates the resulting image on the screen. Another prevalent monitor technology historically includes the Cathode Ray Tube (CRT), while emerging versions include Thin-film transistor liquid crystal display (TFT LCD) and Organic light-emitting diode (OLED) displays.

Digital Light Processing (DLP) is a specialized technology used in video projectors. It features a spinning colour wheel and an integrated array of mirrors. In this architecture, each individual mirror corresponds to a single pixel and functions by reflecting light either toward or away from the projector's optics. This mechanism allows the device to create an image consisting of up to $1024$ shades of grey. The spinning colour wheel then adds the necessary colour data to the projection to complete the final image.

System Graphics and Video Interfacing

Video capability in a computer system is provided by a dedicated component known as a video adapter or display adapter. These adapters facilitate the processing and output of visual data to a monitor or projector. To expand connectivity, a computer can utilize a Universal Serial Bus (USB) controller card, which provides additional USB ports for peripheral devices. For users managing multiple systems, a KVM Switch is employed as a hardware device to control more than one computer using a single keyboard, monitor, and mouse.

High-speed peripheral connectivity and high-definition video transmission are often handled by Thunderbolt $1$ or $2$ ports. These interfaces allow for the connection of high-performance devices such as hard drives, RAID arrays, and network interfaces. Thunderbolt technology is capable of transmitting high-definition video by utilizing the DisplayPort protocol. Other standard video connection options include HDMI $2.0$, VGA, and DVI-D.

Central Processing Unit Architecture

The physical interface between a processor and the motherboard is determined by the socket type. In a Land Grid Array (LGA) CPU socket, the contact pins are located within the socket itself rather than on the processor package. This contrasts with other configurations such as the Staggered Pin Grid Array (SPGA). Other interface concepts include the Zero Insertion Array (ZIA) and Connector Grid Array (CGA).

Memory Systems and Architecture

Dynamic RAM (DRAM) is the standard technology used for a computer's main memory. It operates by storing data as electrical charges that gradually discharge over time. Because of this energy loss, the chip must be constantly refreshed with pulses of electricity to maintain the integrity of the stored data. Static RAM (SRAM), Magnetoresistive RAM (MRAM), and Synchronous Dynamic RAM (SDRAM) represent other variations of memory technology.

Memory chips are often housed on small circuit boards known as modules. A Single Inline Memory Module (SIMM) is a specific type of circuit board that holds several memory chips and is typically found in either a $30$-pin or $72$-pin configuration. Modern systems may also use Dual Inline Memory Modules (DIMM) or Dual Inline Packages (DIP).

Error checking is a critical aspect of memory performance. Non-parity memory is the most common type of RAM used in home and business workstations; it does not perform error checking on the data stored in memory. This is distinct from parity or concurrent error-checking methods utilized in more specialized computing environments.

Power Systems and Electrical Characteristics

The power supply unit (PSU) is the component responsible for converting and distributing electrical power to the computer. The ATX12V is currently recognized as the most common power supply standard on the market. Other power management devices include Power Distribution Units, Modular Power Supplies, and SFX Power Supplies.

Electrical current in computer hardware is classified into two main types based on the flow of electrons. Direct current (DC) refers to an electric current that flows in strictly one direction. Alternating current (AC) is defined as an electric current that periodically reverses its direction and changes its magnitude continuously over time. Modern power supplies are responsible for converting AC from a wall outlet into the DC required by internal components.

Storage Media and Optical Drives

Magnetic media storage continues to be a standard for high-capacity data retention. The traditional Hard Disk Drive (HDD) is a magnetic disk device with storage capacities typically ranging from gigabytes ($GBs$) to terabytes ($TBs$). For long-term archival needs, tape drives are also used.

Solid State Drives (SSDs) represent a significant advancement over magnetic drives. These components store data as electrical charges within semiconductor flash memory. Because an SSD has no moving parts, it is much faster than a magnetic HDD, operates without noise, and is more energy-efficient. Optical storage solutions are also utilized for various data types, such as the Compact Disc (CD), which is used for audio and data, and the Blu-ray Disc (BD).

Input Devices and Specialized Peripherals

Computers utilize a variety of input devices for specific applications. For computer games, simulators, and training applications involving virtual reality, the Virtual Reality (VR) headset is the primary interface. Standard gaming input is facilitated by Joysticks and Gamepads. Other specialized input and capture devices include barcode scanners, magnetic strip readers, voice recognition scanners, NFC devices, terminals, TV tuner cards, and touch screens.

Cooling and Thermal Management

Maintaining optimal operating temperatures is vital for hardware longevity. Cooling systems are categorized based on their power requirements. Active cooling refers to any cooling system that requires electricity to operate, such as fans or Peltier cooling devices. In contrast, passive cooling systems do not require power, typically relying on heat sinks to dissipate thermal energy.