Assignment Chapter 4

Lecturer : Mr. Tri Djoko Wahjono, Ir., M.Sc

Name : Agatha Virgitia Darmawan

Student ID : 1701338122

1.       

     1. How Are Various Styles of System Units on Desktop Computers, Notebook Computers, and Mobile Devices Different?

The system unit is a case that contains electronic components of the computer used to process data.

On desktop personal computers, the electronic components and most storage devices are part of the system unit. Other devices, such as the keyboard, mouse, microphone, monitor, printer, USB flash drive, scanner, Web cam, and speakers, normally occupy space outside the system unit. An all-in-one desktop personal computer is an exception, which houses the monitor and the system unit in the same case. The trend is toward a smaller form factor, or size and shape, of the desktop personal computer system unit.

On most notebook computers, including netbooks, the keyboard and pointing device often occupy the area on the top of the system unit, and the display attaches to the system unit by hinges. The location of the system unit on a Tablet PC varies, depending on the design of the Tablet PC. With the slate Tablet PC which typically does not include a keyboard, the system unit is behind the display.

 On a convertible Tablet PC, by contrast, the system unit is positioned below a keyboard, providing functionality similar to a traditional notebook computer or netbook.

The system unit on an Ultra-Mobile PC, a smart phone, and a PDA usually consumes the entire device.

 On these mobile computers and devices, the display often is built into the system unit.

On most notebook computers, including netbooks, the keyboard and pointing device often occupy the area on top of the system unit, and the display attaches to the system unit by hinges. The location of the system unit on a Tablet PC varies, depending on the design of the Tablet PC. On mobile computers and devices, the display often is built into the system unit. With game consoles, the input and output devices, such as controllers and a television, reside outside the system unit. On handheld game consoles, portable media players, and digital cameras by contrast, the packaging around the system unit houses the input devices and display.

2 2.  What Are Chips, Adapter Cards, and Other Components of the Motherboard?

      The motherboard, sometimes called a system board, is the main circuit board of the system unit. Many electronic components attach to the motherboard; others are built into it. The motherboard contains many electronic components including a processor chip, memory chips, expansion slots, and adapter cards. A computer chip is a small piece of semi- conducting material, usually silicon, on which integrated circuits are etched. An integrated circuit contains many microscopic pathways capable of carrying electrical current. Each integrated circuit can contain millions of elements such as resistors, capacitors, and transistors. Expansion slots hold adapter cards that  provide connections and functions not built into the motherboard.

   3. What Are the Control Unit and Arithmetic Logic Unit Components of a Processor, and What Are the Four Steps in a Machine Cycle?

The processor, also called the central processing unit (CPU), interprets and carries out the basic instructions that operate a computer.

Processors contain a control unit and an arithmetic logic unit (ALU). These two components work together to perform processing operations.

The control unit is the component of the processor that directs and coordinates most of the operations in the computer. The control unit has a role much like a traffic cop: it interprets each instruction issued by a program and then initiates the appropriate action to carry out the instruction.

The machine cycle is a set of four basic operations are :

1.       Fetching is the process of obtaining a program instruction or data item from memory.

2.       The term decoding refers to the process of translating the instruction into signals the computer can execute.

3.        Executing is the process of carrying out the commands.

4.       Storing, in this context, means writing the result to memory (not to a storage medium

4. What Are the Characteristics of Various Personal Computer Processors, and How Are Processors Cooled?
Many personal computer processors are multi-core, with the processor cores working simultaneously on related instructions. These related instructions, called a thread, can be independent or part of a larger task. Software written to support multiple threads, called a multi-threaded program, runs much faster than those in non threaded environments. Processors for traditional notebook computers and Tablet PCs also include technology to optimize and extend battery life, enhance security, and integrate wireless capabilities

A multi-core processor is a single chip with two or more separate processor cores. Two common multi-core processors are dual-core and quad-core. A dual-core processor is a chip that contains two separate processor cores. A quad-core processor is a chip with four or more separate processor cores. Intel produces the Core processor family for high- performance personal computers, the Pentium and Celeron processor families for basic personal computers, and the Xeon and Itanium processor families for workstations and low-end servers. AMD manufactures Intel-compatible processors, which have an internal design similar to Intel processors. Some devices have a system-on-a-chip processor that integrates the functions of a processor, memory, and a video card on a single chip. Heat sinks/pipes and liquid cooling technologies are used to dissipate processor heat. A heat sink is a small ceramic or metal component that absorbs and disperses heat. A smaller device called a heat pipe cools processors in notebook computers, including netbooks and Tablet PCs. Some computers use liquid cooling technology, which uses a continuous flow of fluid(s) to transfer heated fluid away from the processor.

5. What Is a Bit, and How Does a Series of Bits Represent Data?

A bit (short for binary digit) is the smallest unit of data the computer can process. By itself, a bit is not very informative.

 Most computers are digital and recognize only two discrete states: off and on. To represent these states, computers use the binary system, which is a number sys- tem that has just two unique digits — 0 (for off   ) and 1 ( for on) — called bits. Grouped together as a unit, 8 bits form a byte, which provides enough different combinations of 0s and 1s to represent 256 individual characters. The combinations are defined by patterns, called coding schemes, such as ASCII and Unicode.

6.  How Do Program Instructions Transfer in and out of Memory?

      When a program starts, the program’s instructions and data are transferred to memory from storage devices. The program and operating system instructions are in memory, and the program’s window appears on the screen. When you quit the program, the program instructions are removed from memory, and the program no longer is displayed on the screen.
      
            7.  What Are the Various Types of Memory?

The system unit contains two types of memory: volatile and nonvolatile. When the computer’s power is turned off, volatile memory loses its con- tents. Nonvolatile memory, by contrast, does not lose its contents when power is removed from the computer. Thus, volatile memory is temporary and nonvolatile memory is permanent. RAM is the most common type of volatile memory. Examples of nonvolatile memory include ROM, flash memory, and CMOS.

Memory usually consists of one or more chips on the motherboard or some other circuit board in the computer.

RAM is the most common type of volatile memory. RAM (random access memory), also called main memory, consists of memory chips that can be read from and written to by the processor and other devices.

Read-only memory (ROM), flash memory refers to memory chips storing permanent data and instructions. The data on most ROM chips cannot be modified — hence, the name read-only. ROM is nonvolatile, which means its contents are not lost when power is removed from the computer. In addition to computers, many devices contain ROM chips. For example, ROM chips in printers contain data for fonts.

Some RAM chips, flash memory chips, and other memory chips use complementary  metal-oxide semiconductor (CMOS pronounced SEE-moss) technology because it  provides high speeds and consumes little power. CMOS technology uses battery power to retain information even when the power to the computer is off

8. What Are the Purpose and Types of Expansion Slots and Adapter Cards, and What Are the Different Slots for Flash Memory Devices?

An expansion slot is a socket on the motherboard that can hold an adapter card. An adapter card, sometimes called an expansion card, is a circuit board that enhances functions of a component of the system unit and/or pro- vides connections to peripherals. A peripheral is a device that connects to the system unit and is controlled by the processor in the computer. Examples of peripherals are modems, disk drives, printers, scanners, and keyboards.

Sometimes, all functionality is built in the adapter card. With others, a cable connects the adapter card to a device, such as a digital video camera, outside the system unit. Some are a card that you insert in a slot on the computer. Figure 4-27 shows an adapter card being inserted in an expansion slot on a personal computer motherboard. Some motherboards include all necessary capabilities and do not require adapter cards. Other motherboards may require adapter cards to provide capabilities such as sound and video. A sound card enhances the sound- generating capabilities of a personal computer by allowing sound to be input through a micro- phone and output through external speakers or headphones. A video card, also called a graphics card, converts computer output into a video signal that travels through a cable to the monitor, which displays an image on the screen. Today’s computers support Plug and Play, which means the computer automatically can configure adapter cards and other peripherals as you install them. Having Plug and Play support means you can plug in a device, turn on the computer, and then immediately begin using the device.

Unlike adapter cards that require you to open the system unit and install the card on the motherboard, you can change a removable flash memory device without having to open the system unit or restart the computer. This feature, called hot plugging, allows you to insert and remove the removable flash memory and other devices while the computer is running. Removable flash memory includes memory cards, USB flash drives, and PC Cards/ ExpressCard modules

 9. What Is the Difference between a Port and a Connector, and What Are the Differences among the Various Types of Ports?

A port is the point at which a peripheral attaches to or communicates with a system unit so that the peripheral can send data to or receive information from the computer. An external device, such as a keyboard, monitor, printer, mouse, and micro- phone, often attaches by a cable to a port on the system unit. Instead of port, the term jack some- times is used to identify audio and video ports. The front and back of a system unit o n a desktop personal computer contain many ports. On notebook computers, including net- books and Tablet PCs, the ports are on the back, front, and/or sides.

A connector joins a cable to a port. A connector at one end of a cable attaches to a port on the system unit, and a connector at the other end of the cable attaches to a port on the peripheral. Most connectors and ports are available in one of two genders: male or female. Male connectors and ports have one or more exposed pins, like the end of an electrical cord you plug in the wall. Female connectors and ports have matching holes to accept the pins on a male connector or port, like an electrical wall outlet. Sometimes, you cannot attach a new peripheral to the computer because the port on the system unit is the same gender as the connector on the cable. In this case, purchasing a gender changer solves this problem. A gender changer is a device that enables you to join a port and a connector that are both female or both male.

A USB port, short for universal serial bus port, can connect up to 127 different peripherals together with a single connector.

Previously called an IEEE 1394 port, a FireWire port is similar to a USB port in that it can connect multiple types of devices that require faster data transmission speeds, such as digital video cameras, digital VCRs, color printers, scanners, digital cameras, and DVD drives, to a single connector.

Some ports not included in typical computers but sometimes used are Bluetooth, SCSI, eSATA, IrDA, serial, and MIDI. For a computer to have these ports, you often must customize the computer purchase order.

Bluetooth technology uses radio waves to transfer data between two devices.

A SCSI port attaches the system unit to SCSI peripherals, such as disk drives and printers.

An eSATA port connects an external SATA hard disk to a computer.

An IrDA port allows wireless devices to transmit signals to a computer via infrared light waves. A serial port transmits data one bit at a time.

A MIDI port connects the system unit to a musical instrument.

   10.   What Are the Types of Buses in a Computer?

 A bus is an electrical channel along which bits transfer within the circuitry of a computer, allowing devices both inside and attached to the system unit to communicate. The data bus transfers actual data, and the address bus transfers information about where the data should reside in memory. The size of a bus, called the bus width, determines the number of bits that the computer can transmit at one time. The larger the bus width, the faster the computer transfers data. A computer has a system bus, or front side bus (FSB); possibly a backside bus (BSB); and an expansion bus.

   11.   What Is the Purpose of a Power Supply, and How Does It Keep Cool?

Built into the power supply is a fan that keeps the power supply cool. Some have variable speed fans that change speed or stop running, depending on temperature in the system unit. Many newer computers have additional fans near certain components in the system unit such as the processor, hard disk, and ports. Some users install more fans to help dissipate heat generated by the components of the system unit. Mobile users may place their notebook computer on a cooling pad to help disperse the computer’s heat. Some external peripherals such as a cable modem, speakers, or a printer have an AC adapter, which is an external power supply. One end of the AC adapter plugs in the wall outlet and the other end attaches to the peripheral. The AC adapter converts the AC power into DC power that the peripheral requires.

   12.   How Do You Clean a System Unit on a Personal Computer or Mobile Device?

This preventive maintenance task requires a few basic products:

• can of compressed air — removes dust and lint from difficult-to-reach areas; removes sticky liquid spilled on keyboards

• lint-free antistatic wipes and swabs

• screen cleaning solution or 50/50 mix of rubbing alcohol and water (do not use ammonia-based solutions)

• small computer vacuum (or small attachments on your house vacuum)

 • antistatic wristband — to avoid damaging internal components with static electricity

• small screwdriver (may be required to open the case or remove adapter cards)