Computer Components Study Guide In this lesson, we will briefly explore the basics of identifying the parts and components inside of a computer. This lesson is used to introduce the students to the inside of a computer. Going into too much detail too soon will confuse the student. We will learn information that is more detailed as we progress to future lessons. The Case or System Box The case contains all of the components and parts that make up a computer. There are two basic physical designs. These are the "DESKTOP CASE" and the "TOWER CASE." Cases are further divided into sub-categories of MINI, MID, and FULL, which usually designates how small or large the case is. Simply put, cases are metal boxes for computers that have similarities in their dimensions and design. However, what makes them different is the way they sit, and where or how components and parts connect inside. The desktop case usually sits on the desktop, lays flat, and does not take up much room in height. The monitor usually sits on top of the desktop case. The tower case looks like a desktop case sitting up on its side. It takes up very little space on the desktop, but it is tall and therefore takes up more room in height. However, you can conveniently access the inside of a tower case without having to move the monitor. Sometimes the tower sits on the floor, or under a desk. The chassis is the main metal structure that not only holds the case together, but which is also connected to the ground in the electrical circuit of the computer. The case incorporates bays, slots and specific areas for connecting all of the computer parts and components inside of it. Examples of Cases Additionally, the case can be either an AT or ATX type. AT CASE Advanced Technology Requires an AT motherboard and power supply. Introduced by IBM (older form factor & ATX CASE Advanced Technology Extended Requires an ATX motherboard and power supply. Introduced by INTEL (newer form factor and
design) design) Power needs to be shut off manually by using switches or buttons. Power shuts off without manual intervention, and is specifically designed to be controlled by software. Some motherboards (only a few) can use either the AT or ATX cases. These motherboards have 2 distinct and separate connectors for the power supply. When purchasing either type case, it is important to make sure that the slots and holes correctly align with the motherboard. Believe me when I say that there are differences, which are not noticeable, until you try to attach and align the motherboard to the chassis. What's Inside Of A Computer Case? The case contains major parts & components that make a computer work. (1) 1. Motherboard (also called the mainboard or the main circuit board in the computer) 2. CMOS and BIOS (see additional terms - below) 3. Various Drives fi Floppy Drives fi Hard Drives fi CD-ROM Drives (Read-Only, Re-Writable, and DVD) fi Tape Drives (usually found in older systems for backup purposes very slow and overheat easily) 4. System speaker (a small speaker inside the case not to be confused with sound card speakers)
5. Power Supply (device inside the case that supplies power to the internal components of the computer) 6. Cooling Fans (necessary for keeping sensitive microcomputer chips and computer components at safe temperatures) 7. Other Small Parts (such as LED's, buttons, and switches) The case contains major parts & components that make a computer work. (2) 8. USB and Infrared capabilities (in newer computer systems only) 9. Memory fi RAM (Random Access Memory temporary memory that is erased when the computer is turned off) fi ROM (Read Only Memory that can not be re-programmed) fi FLASH ROM (Read Only Memory that can be re-programmed and needs a battery for its power) fi EEPROM (Electronically Erasable Programmable Read Only Memory). 10. Various Adapter Cards I/O Cards Input/Output fi Video Display Card (some are integrated into the motherboard connects to the monitor) fi Sound Card (some are integrated into the motherboard) fi IDE and SCSI cards (some are integrated into the motherboard) fi Parallel Port Cards (for printers, scanners, & some external drives some are integrated into the motherboard) fi Serial Port Cards (for communications also called COM Ports some are integrated into the motherboard) fi Game Cards (some are integrated into the motherboard & some are integrated into the sound card) fi Accelerator Cards fi Internal Modems (for communication through a telephone line) fi Network Cards (NIC - for communication through a network) Related Facts (1) The entire combination of parts and components are connected to each other, inside the case, through the motherboard, by a combination of FLAT RIBBON INTERFACE CABLES, WIRES, and ELECTRONIC CIRCUITS. The BUS or DATA BUS is a series of interconnecting electrical leads in the circuit board, which carry signals. The bus is further broken down into bus sections. It transports the information or data, in the form of electric impulses, back and forth between all of the components in a computer, enabling them to communicate with each other. People who are just learning about computers sometimes confuse the bus with the expansion slots. This is incorrect. The EXPANSION SLOTS are special slots on the motherboard where the adapter cards are attached and held secure, so that devices attached to the cards can communicate with each other through the bus. However, the electrical leads in the expansion slots connect to the bus. The design, dimensions, and amount of electrical leads in the slots are determined by the bus
architecture in use when the motherboard was made. Different bus architectures can be used on the same motherboard at the same time. The edge on the adapter card decides which type of slot it can be used in. Again, this is pre-determined by the bus architecture being used on the motherboard. The VIDEO and IDE adapters are the only adapters that are necessary for the computer to operate. Although the other adapters give the computer more advantages and capabilities, they are not absolutely necessary. Related Facts - (2) A computer can operate without a HARD DRIVE or CD-ROM DRIVE, but only if it has a FLOPPY DRIVE to boot from. Of course, you would need an awful large quantity of floppy disks in order to do anything with the computer. Additionally, it would be very inconvenient if you had to continuously change floppy disks in and out of the drive to accomplish anything. A computer can operate without a FLOPPY DRIVE, but only if it has a working HARD DRIVE. If the HARD DRIVE can not boot properly, a FLOPPY DRIVE is needed so that the computer can be booted from a special floppy boot-disk. Some newer computers can be started from the newer CD-ROM DRIVES, but only if it has a special formatted BOOT-UP DISK loaded, and if CMOS SETUP is correctly configured for this. However, without a HARD DRIVE to work with, the CD-ROM is useless by itself. A certain amount of MEMORY is needed to operate a computer. That amount can vary depending on how old or new the computer is, what OPERATING SYSTEM is being used (DOS/Windows), and how much memory other software that is used on the computer requires. Different types of memory have different capabilities and limitations. Newer, more recent computers require more memory than older computers. (We will explore this further in a future lesson.) Additional terms you need to be familiar with concerning the inside the computer. CPU (Central Processing Unit) - The CPU is sometimes referred to as the brains of the computer, and is where most of the complicated arithmetic calculations happen. The CPU can get extremely hot, and needs to be constantly cooled by a fan. Some CPU's use a heat sink to cool them. The metal in the heat sink absorbs the heat from the CPU, helping to keep it from overheating. BIOS (Basic Input Output System) The BIOS is a computer chip that is responsible for booting the computer by providing a basic set of instructions to make this happen. It also conducts several tests to make sure that everything is working so that the computer can operate properly. In order for the BIOS to accomplish these tasks, it needs to know specific information about the computer from the CMOS. CMOS (Complementary Metal Oxide Semiconductor) also called CMOS RAM. CMOS has one main job - to store information and specific settings about everything inside your computer. BIOS needs this information so that it can make the computer do what it is supposed to do. For example, if the BIOS does not know the size and other important information about the hard drive installed in the computer, it will not know how to work with it. The BIOS can not
do anything unless it knows exactly what the computer component is, or what it needs to operate. A battery powers the CMOS, and if the battery dies, CMOS will lose all the information that it had stored.