This document provides an overview of the major components of a personal computer (PC) and how they work together. It describes the standard equipment in a PC including the case, motherboard, processor, RAM, hard drive, video subsystem and input/output cards. It also explains the boot process that occurs when a PC is powered on to initialize the hardware and load the operating system.

1. CS 435 Computer Hardware Troubleshooting

2. Objectives Identify the major components of a PC system Define how these components work Identify the boot processes Understand basic PC terminology

3. Personal Computer (PC) was introduced in the late 1970s and early 1980s. The PC is a scaled-down version of a mainframe or mini-computer. Each of the operational components of a large computer system is present in a PC,

4. SYSTEM OVERVIEW When first conceived, the computer was designed to provide the same functionality as the human brain. It has developed into a machine that can perform some of the same tasks as a person. The case and power supply house, much as the human body houses the brain and vital organs and provides energy to those components.

5. STANDARD EQUIPMENT Case, motherboard, processor, RAM Hard drive I/O cards Keyboard and mouse Monitor Operating system Applications

6. Case/Power Supply Is the shell that houses and provides power to all the PC’s internal components. Originally, all PCs were housed in cases that sat on the desktop. XT – 1st Smaller case because it housed the original IBM-compatible PC and XT PC. AT – 2nd IBM-compatible case PC. Larger footprint than the XT case and was designed with a larger, higher-wattage power supply that could support more devices and I/O cards. Tower-style cases were developed. These cases stand vertically and can be placed next to the monitor or on the floor under the desk.

7. Motherboard and Processor head providing connection from the brain to the rest of the body. Brain The processor, also called the Central Processing Unit (CPU) The brain of the PC and plugs into a socket on the motherboard.

8. Motherboard Is the largest board in the computer case and is mounted to the case. The battery, CMOS, BIOS, processor chip socket, RAM chip sockets, and bus connectors are located on the motherboard.

9. Processor Plugs into a custom socket on the motherboard. Different sockets are needed for different processors. The actual “brain” of a computer and performs all the computer’s mathematical computations. **Intel 8088 processor - Original IBM-compatible PC.

10. Memory Memory in the human body is a component of the brain. Random Access Memory (RAM) is typically plugged into the motherboard and provides a fast storage area for the processor to operate. Volatile

11. HardDrive Is a permanent mass-storage memory device used to store applications and data when they’re not needed by the processor. Non-Volatile The interface cards, known as Input/Output (I/O) cards, provide an interface from the processor to external components and are comparable to the arms, legs, eyes, ears, and mouth of a person.

12. CMOS/BIOS CHIP CMOS chip Stores hardware configuration information while the PC is turned off and is powered by a small battery. BIOS chip Is a non-destructive memory chip that stores the Power On Self Test (POST) and a basic communications program. known as a bootstrap loader .

13. Memory Random Access Memory (RAM) Plugs into the motherboard Processor runs programs from RAM RAM provides a fast working area where the processor stores data while performing computations.

14. Video Subsystem Is responsible for displaying information on the monitor. Is responsible for displaying information on the monitor. Monitor resolution - is measured in pixels; Pixel - is the smallest addressable point on a monitor. Dot pitch - The size of the pixel for the monitor.

15. Video Card Types MDA (Monochrome Display Adapter) CGA (Color Graphics Adapter) EGA (Enhanced Graphics Adapter) Provide a digital signal to the monitor, which converts it to analog and displays it on the screen.

16. Video Card Types VGA (Video Graphics Adapter) SVGA (Super VGA) AGP (Advanced Graphic Port) and other graphics adapters. Provide an analog signal to the monitor.

17. THE BOOT PROCESS When power is first applied to a PC, the system must perform a number of tasks before the user can use the computer.

18. Steps involved in the boot process Power is applied. The CPU sends out an initialization (INIT) signal. The CPU loads the program stored in the BIOS into RAM and runs the program. POST results are compared to information in CMOS. The CPU tells the boot disk drive to load the operating system and run it. The motherboard has a small IC chip, known as the CMOS chip, which is powered by a battery. The CMOS chip stores the hardware configuration information along with the current date and time.

19. Analogy If you -- want to work on a document, you take it out of a file cabinet -- and place it on your desk --, make whatever changes need to be made, then place the document back in the file cabinet. The size of your desktop determines how big a document you can place on the desktop, just as the amount of installed RAM determines how many applications and how much data can be in active memory at one time.

20. TY =)