Inside System Unit Computer Science notes Chapter 4 short & long question
It holds many of the basic electronic parts of the system, such as the central processing unit (CPU) and memory, and affords connectors for other peripherals. Unlike a backplane, a motherboard includes significant sub-systems such as the processor and other components.
Q.2) Give short answers to the following questions
i) Differentiate between CPU and System unit.
The difference between CPU and system unit is as follows:
|Structure||It is a small chip.||It is a case.|
|Components.||It is a component of motherboard which resides in system unit casing.||It contains different components inside it like Motherboard etc.|
|Computing||It has core participation in computing||It do not have participation in computing|
|Functionality||Functional part of the computer.||Non-functional part of the computer.|
|Other names||Also known as brain of the computer.||Also known as a “tower” or “chassis”|
ii) Define two main types of computer casings.
A computer casing is also known as computer chassis, cabinet, box, tower, enclosure, housing, system unit or a case. It contains most of the components of computer inside it. This computer casing is made up of steel, aluminum, plastic, wood or Lego etc.
Types of computer casing:
Computer casing is of two types:
- Desktop casing
- Tower casing
It is a type of casing which is designed to keep on desk. Monitor is placed over it. It is an old style of casing.
It is type of casing which is placed at the side of monitor. It is a modern casing and it is more attractive and common.
iii) List different parts of a motherboard.
The main circuit board in a computer system with which all components of the system unit are attached is called a motherboard. It is also called logic board, system board, or planar board.
It is the foundation of a computer located at the bottom of the computer case. It allocates power to the CPU, RAM and all other components of the hardware.
Parts of Motherboard:
The motherboard has the following parts:
- PCI slots
- Southbridge ( Input/ Output controller Hub)
- Northbridge( Memory controller hub)
- IDE Connector
- DRAM memory
- ATX Power connector
- CPU Fan and heatsink
- CPU Socket
- Connectors for peripheral devices (mouse, keyboard, monitor, printer etc.)
- CMOS Backup battery
iv) What is role of BIOS in computer system?
BIOS stand for Basic Input Output System. It is a ROM chip located on motherboard. It allows user to access and set up computer system at the most basic level. To load and start an operating system is the basic function of BIOS. There are four main functions of computer BIOS:
- POST- It test the computer hardware and make sure no errors exist before loading the operating system.
- Bootstrap Loader- Locates the operating system. If a capable operating system is located, the BIOS will pass control to it.
- BIOS drivers- Low level drivers that give the computer basic operational control over your computer’s hardware.
- BIOS or CMOS setup- Configuration program that allows you to configure hardware settings including system settings such as computer passwords, time and date.
Using BIOS a user can also:
- Configure hardware
- Set the system clock
- Enable or disable system components
- Select bootable device sequence
- Set password for system and user login
v) Differentiate between a port and a slot.
A difference between a port and a slot is as follows:
|Refers to||Port refers to the holes in the box.||Slot refers to connectors on a circuit board.|
|Used for||Ports are used to connect peripheral devices.||Slots are used to insert new devices/extension cards in it.|
|Base||Ports may be hardware based as well as software based.||Slots are only hardware based.|
|Types||Ports can be hardware based or software based.||Slots can be PCI or AGP slots.|
|Examples||Hardware port: Game port, USB port etc.Software port: Port 80 is the for “http”, Port 25 is for mail||PCI slots used by Network card, AGP slots used by video cards|
vi) Name different types of data cables with their purpose of use.
A cable is a wire used for transmission of signals. Different types of cables and their purpose of use is as follows:
- IDE Cable: IDE stands for integrated drive electronics .IDE is standard interface for connecting a motherboard to storage device such as hard drives and CD ROM/DVD drives.
- SATA cable: SATA stands for serial advanced technology attachment to serial ATA .It is used to connect hard drives to a computers motherboard.
- FD cable:FD stands for floppy disk. FD cables are used in past to connect floppy drives to computer.
vii) Why cooling system is important for a computer?
Cooling system is important in computer to maintain the temperature level inside the computer bus. Hardware inside the system unit like CPU, video card or hard drive generates heat in the system. It uses heat sinks and fans to reduce the temperature of computer.
If there is no cooling system in computer than temperature will reach at very high level which cause damage to computer parts.
viii) Differentiate between SIMM and DIMM.
The difference between SIMM and DIMM is as follows:
|Pins||SIMM pins are connected each other.||DIMM pins are independent.|
|Channel||SIMM provide 32-bit channel.||DIMM provide 64-bit channel.|
|Pairing||SIMM pairs two pins.||DIMM eliminated that practice of pairing two pins.|
|Replacement||SIMM is not a replacement technology.||DIMM is a replacement technology.|
Extensive Questions computer science part 1 for kpk textbook bord
Q.3) Give detailed answers to the following questions
i) Discuss different types of expansion cards.
An expansion card (expansion board) is an add-on circuit is used to connect devices such as modems,sound cards, graphics cards and network interface cards to the computer.
Expansion boards fit into sockets on the computer motherboard called expansion slot.These expansion board or card to the main components of the computer.
There are four main type of expansion cards are:
(a) Sound Card
(b) Video Card
(c) Modem Card
(d) Network Interface Card
A sound card is an expansion board that enables a computer to mainpulate and output sounds.
Sound cards are necessary for nearly all CD- ROMs have become commonplace on modern personal computers.
Sound cards enable the computer to output sound through speakers connected to the board, to record sound input from a microphone connected to the computer, and to mainpulate sound stored on a disk.
A video card also know as video adapter,graphics accelerator card, display card or graphics card is an expansion card whose function is to generate output images to a display unit.Some cards contain dual GPU for additional performance.Because graphics cards work hard they generate heat.For this reason most high- performance video cards utiliize built-in fans or heat sinks to pulls heat away from the GPU.
The term modem is derived from modulator and demodulator.The main purpose of modem is to convert digital data into analog signals before sending it over the transmission line and convert it to digital signal on the receiving computer.
Network Interface Card:
A network interface card is an expansion board that is used to control the exchange of data between the computer and a network.
Most NICs are designed for a particular type of network,such as Etherent or Token Ring.
Modern network interface cards are produced for PCI expansion slots.
ii) What is port? Explain different types of ports in computers.
A port is an endpoint of communication of in an operating system . It is used for hardware devices.
A port is always associated with an IP address of a host. A port is identified for each address and protocol by port number.
Types of ports:
The ports are of many types. Some of them are as follows:
a) Serial ports
b) Parallel ports
c) PS/2 Port
d) USB Port
e) Fire Wire Port
A port that is used in serial communication in which only one bit is transferred at a time. A serial port is a general purpose interface that can be used almost any type of device like modem mouse printers. Serial ports consist of 9 or 25 pins. One pin is used for data transfer in rest are used to transmit control signals. These ports were introduced by IBM for communication these ports are called COM1, COM2 and COM3. These ports have been replaced with USB ports in modern computers.
A parallel ports is a type of interface found in computer for connecting peripherals. A parallel port is a parallel communication physical interface .it is also known as printer port. Parallel port have 25 pin out which 8 pins transmit on byte of information rest of them are used for transmitting control signals. Parallel port are named as LPT1, LPT2 and LPT3.In today’s modern computers these ports have been replaced with USB ports.
PS/2 port referred to mouse and keyboard port.it is used to connect computer, mouse and keyboard. The e PS/2 port is a 6 pins mini plug. The purple PS/2 connector is used for keyboard and green is used for mouse.
USB stands for universal serial bus. A USB is a standard cable connection interface on personal computers and consumer electronics .USB ports allow stand-alone electronic devices to be connected via cables to a computer. USB ports can also supply electric power across the cable to devices without their own power source.
Fire wire port:
Fire wire ports are external connector, similar to a usb port, which provides a high-speed connection between a computer and peripheral devices. Fire wire ports are able to transfer data at a rate of up to 400 Mbps. Fire wire ports has four or six pins .in a six pin connector has two extra pins that are used to provide electric power laptop computer use four pin fire wire port as they do not provide electric to devices connected to it.
iii) Explain different types of ribbon cables.
A thin cable containing many parallel wires because o their shape, ribbon cables are ideal for situations where space need to be conserved. They’re used, for example, with computer chassis tp connect disk drives to the disk drive controller.
There are following types of ribbon cables:
a) IDE Cable
b) SATA Cable
c) FD cable
IDE stands for integrated drive electronics. IDE is standard interface for connecting a motherboard to storage device such as hard drives and CD ROM/DVD drives. The original IDE had a 16 bit interface that connected two devices to a single-ribbon cable. IDE’S development increased data transfer rate speed and reduced storage device and controller issues. IDE is also known as advanced technology attachment or intelligent drive electronics.
SATA stands for serial advanced technology attachment to serial ATA. It is used to connect hard drives to a computers motherboard. SATA transfer rate start from 1.5 to 6 GB per second. Serial ATA has replaced the IDE cables. The interface that provides communication for SATA cable are SATA1,SATA2 and SATA3,there speed is 1.5GB/ sec,3GB/sec and 6GB/sec respectively.
FD stands for floppy disk. FD cables are used in past to connect floppy drives to computer. Floppy drives are not used now a days, because of this FD cables are not used with modern microcomputers.
iv) Discuss different types of memory chips.
Memory chips are devices that are used for storing data and code either temporarily or permanently for processing, commonly used RAM chips are
ROM and PROM chips can never be changed, while EPROMs and EEPROMs can be modified.
Types of memory chips:
Some of the common types of memory chips are given below:
SIMM stands for single in-line memory module. It is a type of memory module which was developed in 1983. The SIMM circuit board holds six to nine memory chips, the ninth memory chip is used for error checking (parity or non – parity). The SIMM was used with computers using a 486, early Intel Pentium and compatible processors. SIMM is 32 bits wide so, when it is used with 64-bit processor, two memory modules of SIMM are used their.
DIMM stands for dual in-line memory module. It is located on computer motherboard. DIMM is a upgraded form of SIMM. As compared to SIMM it has more storage capacity and faster speed. Working of one DIMM module is equalant to two SIMM module . A DIMM module consist of 168-pins connector and can transfer data at rate of 64 bits.DIMM has a storage capacity from 64MB and 512MB.
SDRAM stands for Synchronous Dynamic Random Access Memory. It is a type of RAM that can run at much higher clock speeds than conventional RAM. SDRAM is upgraded technology of DRAM. It synchronizes itself with the CPU’s bus and is capable of running at 133 MHz. SDRAM has a rapidly responding synchronous interface. It operates in synch with system bus. SDRAM waits for the clock signal before it responds to control inputs. SDRAM is used in modern computers and its new technologies DDR1, DDR2 and DDR3 are available in market.
DDR SDRAM stands for Double Data Rate Synchronous Dynamic Random Access Memory. It has a double speed than SDRAM. It transfers data at double speed. It has improved memory clock speed. It can read and write two consecutive words per clock cycle.
v) What is Bus? Explain different types of buses in computers.
The CPU of personal computer has to send and receive various types of information and data to and from all other devices and components inside a computer and to devices connected to outer word of computer.
If we remove the case of CPU then we will see that there is a mesh of wires or electronics pathways connected between motherboard and other components. These are the wires or electronics pathways that join various components together to communicate with each other. This network of wires or electronics pathways is known as ‘BUS’.
The bus that is used to connect the main components of computer is called the System bus (A shown in figure below). The system bus is divided into three main categories:
It used to send out signals to coordinate and manage the activities of the motherboard components.
It is used to transfer data between peripherals, memory and the CPU. It is a very busy pathway.
It passes memory addresses to one another over the address bus. It is used to identify particular locations (addresses) in main memory. The width of the address bus (that is, the number of wires) determines how many unique memory locations can be addressed.
vi) Write note on SDRAM and DDR SDRAM.
SDRAM stands for Synchronous Dynamic Random Access Memory.
It is a type of RAM that can run at much higher clock speeds than conventional RAM. SDRAM is upgraded technology of DRAM. It synchronizes itself with the CPU’s bus and is capable of running at 133 MHz. SDRAM has a rapidly responding synchronous interface. It operates in synch with system bus. SDRAM waits for the clock signal before it responds to control inputs. SDRAM is used in modern computers and its new technologies DDR1, DDR2 and DDR3 are available in market.
DDR SDRAM stands for Double Data Rate Synchronous Dynamic Random Access Memory. It has a double speed than SDRAM. It transfers data at double speed. Its speed is measured in MHz. It has improved memory clock speed. It can read and write two consecutive words per clock cycle. DDR-SDRAM is also called DDR1-SDRAM. DDR2, DDR3 and DDR4-SDRAM are developed after this but motherboards using DDR1- SDRAM are not compatible with DDR2, DDR3 and DDR4-SDRAM.