Capítulo 1: Introducción al hardware de computadoras personales
Introduction to Personal Computer Hardware and Learning Objectives
The IT Essentials 8.0 course, specifically Chapter 1, provides a comprehensive introduction to personal computer hardware. This chapter serves as a foundational guide for understanding how various components interact within a system. The primary objectives are to explain the maintenance and safety of computer components, describe the characteristics and functions of these components, and provide instructions for the physical disassembly of a personal computer (PC).
Two types of activities are integrated to reinforce learning. "Check Your Understanding" (formerly Interactive Activities) are designed for students to quickly assess their comprehension of content before moving forward; these do not impact grades. "What Do You Know So Far?" activities invite students to guess or think about topics before they are formally presented, serving as an introductory thought exercise. While these also do not affect grades, the feedback provided in these activities often contains content found in subsequent tests and exams, making their completion essential.
Security, Electrical Safety, and Electrostatic Discharge (ESD)
Ensuring safety when working with hardware is paramount. Electrical devices have specific power requirements that must be met to avoid damage. For instance, AC adapters are manufactured for specific laptop models; interchanging AC cables between different laptops or devices can cause significant damage to both the adapter and the computer. Furthermore, certain printer components, such as power supplies, operate at high voltage and require careful handling according to the manufacturer's manual to prevent fires, injuries, or accidents.
Electrostatic Discharge (ESD) occurs when there is a buildup of electrical charge on a surface that comes into contact with a surface of a different charge. ESD can destroy sensitive electronic components if not managed. Remarkably, a human being must accumulate a minimum of of static electricity before they can even feel an ESD event. To prevent damage, technicians should keep all components in antistatic bags until installation, use grounded mats on workbenches and in work areas, and wear antistatic wrist straps when working inside a PC case.
Safety training is categorized into four distinct parts for laboratory practice: Personal Safety, Electrical Safety, Fire Safety, and Compliance with Government Regulations. These protocols ensure that both the technician and the hardware remain protected during maintenance and assembly procedures.
Computer Cases and Power Supply Units (PSU)
The computer case, or cabinet, houses internal components including the power supply, motherboard, Central Processing Unit (CPU), memory, disk units, and adapter cards. The term "form factor" refers to the physical design and appearance of the case. Common form factors for desktop computers include Horizontal, Full Tower, Compact Tower, and All-in-One. Depending on the manufacturer, cases may also be referred to as Super Tower, Mid Tower, Mini Tower, or Cube cases.
The Power Supply Unit (PSU) is responsible for converting alternating current (AC) power from a wall outlet into the lower-voltage direct current (DC) required by internal components. Common form factors for power supplies include Advanced Technology (AT), which was used in legacy systems; AT Extended (ATX), an updated version of AT; ATX12V, which is the most common PSU on the market today; and EPS12V, originally designed for network servers but now common in high-end desktops.
Power supplies include various connectors to power specific components. Examples include the 20 or 24-pin main slot connector for the motherboard, the SATA keyed connector, the Molex keyed connector, the Berg keyed connector, the 4 to 8-pin auxiliary power connector, and the 6 to 8-pin PCIe power connector. The most common voltages supplied are , , and . Generally, and are used for digital circuits, while is used to power disk drive motors and fans. A power supply may feature single, double, or multiple "rails," which refer to the Printed Circuit Board (PCB) inside the unit to which external cables connect. While a PC can tolerate slight fluctuations, major deviations can lead to PSU failure.
Motherboards, CPUs, and Cooling Systems
The motherboard acts as the backbone of the computer, consisting of a Printed Circuit Board (PCB) that contains buses or electrical paths to interconnect electronic components. These components are either soldered directly or added via sockets, expansion slots, and ports. Key motherboard components include the CPU, Random Access Memory (RAM), expansion slots, the Chipset, BIOS/UEFI chips, SATA connectors, and internal USB connectors.
The Chipset consists of integrated circuits that control hardware interaction between the CPU and the motherboard. It is typically divided into two parts: the Northbridge, which controls high-speed access to RAM and the video card, and the Southbridge, which manages communication with slower devices like hard drives, USB ports, and expansion slots. Common motherboard form factors include ATX, Micro-ATX, and ITX, which dictate the physical layout and power requirements.
The Central Processing Unit (CPU) is the "brain" responsible for interpreting and executing commands. It is a small microchip residing in a CPU package. The connection between the motherboard and the processor is the CPU socket. Modern CPU architectures use either a Pin Grid Array (PGA), where pins are on the bottom of the processor package, or a Land Grid Array (LGA), where the pins are located within the socket itself.
Maintaining proper temperature is critical for performance. Cooling solutions are classified as active or passive. Active solutions, such as case fans or CPU fans, require power to operate. Passive solutions do not require power and typically involve reducing component clock speeds or using heat sinks to dissipate heat from chips.
Memory Architecture: ROM and RAM
Computer memory is stored in chips as bytes, where one byte is a block of eight bits represented as 0s or 1s. Memory is divided into Read-Only Memory (ROM) and Random Access Memory (RAM). ROM is non-volatile and includes types such as PROM, EPROM, and EEPROM. High-speed RAM is the temporary storage area for data and programs currently being accessed by the CPU. RAM is volatile, meaning its contents are lost when power is removed. Increasing RAM can improve system performance, though the maximum capacity depends on the motherboard.
RAM types have evolved significantly over time, including Dynamic RAM (DRAM), Static RAM (SRAM), Synchronous DRAM (SDRAM), and various iterations of Double Data Rate (DDR) such as DDR2, DDR3, DDR4, DDR5, and GDDR (specifically for graphics). Memory chips are soldered onto boards to create modules like DIP, SIMM, DIMM, and SODIMM (typically for laptops). SRAM is the fastest type and is used as cache memory. Cache is categorized into three levels: L1 (integrated into the CPU), L2 (historically on the motherboard but now often in the CPU), and L3 (used in high-end workstations and servers).
To ensure data integrity, various error-checking methods are used. Non-parity memory does not check for errors. Parity memory uses 8 bits for data and 1 bit for error checking. Error Correction Code (ECC) memory is advanced enough to detect multiple-bit errors and correct single-bit errors in memory.
Expansion Cards and Storage Devices
Adapter cards increase PC functionality by adding controllers or replacing faulty ports. Common cards include Sound Adapters, Network Interface Cards (NIC), Wireless NICs, Video/Display Adapters, Capture Cards, TV Tuners, USB Controller Cards, and eSATA cards. These are installed in expansion slots such as PCI, Mini-PCI, PCI-X, PCIe (PCI Express), Riser cards, or AGP (Accelerated Graphics Port).
Data storage provides non-volatile retention of information and is classified by the medium used: magnetic, solid-state, or optical. Magnetic storage includes Hard Disk Drives (HDD) and Tape Drives, representing binary values as magnetized areas. Tape drives are primarily used for archiving and can range from a few gigabytes to many terabytes. Solid-State Drives (SSD) use semiconductor flash memory to store data as electrical charges, making them faster, more silent, and more energy-efficient than HDDs. SSDs come in form factors similar to HDDs, as expansion cards, or as mSATA/M.2 modules. The NVMe (Non-Volatile Memory Express) specification allows SSDs to connect directly to the PCIe bus for higher performance. Solid-State Hybrid Drives (SSHD) combine a magnetic HDD with an integrated flash memory cache.
Optical storage uses lasers to read and write data to removable media. Types include Compact Discs (CD) for audio and data, Digital Versatile Discs (DVD) for digital video and data, and Blu-ray Discs (BD) for high-definition video. These can be Single Layer (SL) or Double Layer (DL), with the latter doubling the storage capacity. They are further classified as read-only, recordable (write once), or re-writable.
Ports, Cables, and Peripherals
Video ports connect monitors to the PC using various signals. Common ports/cables include DVI, DisplayPort, HDMI, Thunderbolt (versions 1, 2, and 3), VGA, and RCA. Other I/O ports for peripheral devices like printers and scanners include PS/2, Audio/Game ports, Network (Ethernet), SATA, IDE, and USB. In cases where connections do not match, adapters (physical connection change) or converters (signal technology change) are used, such as DVI to VGA or HDMI to VGA.
Input devices allow user communication with the computer. Traditional devices include the mouse, keyboard, scanners (ADF or flatbed), joysticks, and KVM (Keyboard, Video, Mouse) switches. Newer inputs include touchscreens, digital styluses, magnetic stripe readers, barcode scanners, digital cameras, webcams, signature pads, smart card readers, and microphones. The most modern inputs utilize NFC (Near Field Communication), biometrics (facial, fingerprint, or voice recognition), and Virtual Reality (VR) headsets.
Output devices convert binary information into a human-understandable format. Monitors and projectors primarily use LCD, LED, OLED, or DLP (Digital Light Processing) technology. Output brightness for projectors is measured in lumens. Audio output is handled by speakers and headphones (wired or wireless via Wi-Fi or Bluetooth). Printers create hard copies on paper or plastic (3D printers) and include inkjet, impact, thermal, and laser types, all requiring specific media and drivers.
Finally, Virtual Reality (VR) and Augmented Reality (AR) represent advanced output/input paradigms. VR creates a fully simulated 3D environment, typically blocking out all ambient light. AR superimposes digital images and audio onto the real world in real-time, usually without blocking the user's view of their physical surroundings.
Questions & Discussion
Section 1.1: The instructor may facilitate a discussion regarding the types of personal computers students own, the differences between desktops and laptops, and the specific security considerations for each device type.
Section 1.2: Discussions typically focus on identifying the hardware components in students' own devices, their specific specifications, and how those specs impact performance. Interactive demonstrations may involve passing around physical components or cables to identify them and their corresponding ports.
Section 1.3: The class may discuss whether anyone has previously assembled or disassembled a PC or replaced a laptop component. If physical hardware is unavailable for disassembly, a video demonstration of a PC teardown is provided.
Laboratory Exercises: Practical labs include "Safety," which covers personal, electrical, and fire safety alongside government compliance, and "Disassembling a Computer," which requires students to use the technician's toolkit to physically take apart a PC while following strict safety procedures.