Operating System Architectures And Network Looking Computer Science Essay

Published Date: 02 Nov 2017

Module Leader: Gill Whitney

Rameez Qureshi

M00396506

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Introduction………………………………………………………………………………….3

Processor………………………………………………………………………………………3

Memory………………………………………………………………………………………..4

Primary……………………………………………………………………………………4

Secondary…………………………………………………………………………….….6

Input and Output elements……………………………………………………………7

To/From the User…………………………………………………………………….7

To/From the Network………………………………………………………………8

Support Elements…………………………………………………………………………..9

Conclusion……………………………………………………………………………………10

References……………………………………………………………………………………11

Introduction

Some types of peripherals are important parts to a system for example a keyboard a mouse because without them the user would have major difficulty using the system. You can still operate the computer system without a mouse as the most important hardware would be considered the keyboard which is the input from the user.

This report will also be revolving around primary and secondary memory and inputting and outputting the result to the user. (1 Figure)

File:Information processing system (english).svg

Figure 1

Processor

There are three components found under the CPU. One is the control unit, which generally accesses instructions which are stored in RAM. The other is the ALU also known as Arithmetic Logic Unit that performs arithmetic calculations for example multiplication, subtraction, addition, division and logic operators such as less than Greater than and equal.[5]

A Register which is found within the CPU itself, the main purpose of having a register is to retrieve data quickly. This part of the CPU also contain other registers such as Program counter (PC), (IR) Instruction register, (ACC) Accumulator, (MAR) Memory Address Register and (MBR) Memory Buffer Register.[2]

Von Neumann model

Von Neumann was a mathematician born in Hungary(1903-07) developed a basic model for computers which we are still using today. The model included CPU, Input, output, two types of Storages one permanent and other temporary. [24]

Program counter(PC) is a Register which holds the memory address of the next instruction or task that has to execute in a program. The Program counters would keep the CPU inform, about where it has reached, with the instructions or tasks. This will make sure that the program is correctly executed, due to Program counter taking each step, one by one.

Instruction Register(IR) is a register which is used to hold the current instruction in the processor while it is being decoded and executed, this is to reduce the speed of execution.

Accumulator(ALU) is used to stores the answer of operations which is performed by the Accumulator ALU.

Memory Address Register(MAR), this register is used for storing memory addresses, which are usually the instruction that is also stores in the instruction register. The control unit then goes to the MAR. The instruction can then be accessed for obtain data.

Memory Buffer Register(MBR), this register deals with instruction or data obtained from the memory, it is first placed in the (MBR). The move is to determine or carry out instruction.

The control unit Fetches instructions from memory, decodes the instruction, transfers the data which gained from decoding and then finally execute the instruction or data. This is also knows as fetch and execute cycle. The fetch cycle uses the memory, this means it picks the instruction from the memory (the instruction given by the Control unit) and then it saves the value to the Memory address register. The control unit then checks the value in the memory address register, before fetching the instruction from memory. The value found in the memory is then saved in the memory buffer register before giving the value to the Instruction Register. [3] [4]

Memory

Memory is a central part within a computer. Memory basically means to  Etore data E this can be data that is stored on a permanent or temporary basis. The two main types of memory are primary memory and secondary memory. Both types of memories are not alike when it comes to level of capacity, speed and cost. Computers can have several types of memory which can be fitted into the computer meaning it could be internal or external memory. The data or information stored on the memory can be easily stored.

Primary Memory

Primary memory is a Volatile memory, meaning, if the system is turned off the data or information can be lost. RAM,SRAM,DRAM and ROM are the different type of memory, which is found on computers or used. which is identical to primary memory and Read-Only Memory (ROM).

RAM  Ethis is used as primary storage within a computer system. As calculations are performed, it has the on-going process of recording and obtaining information and data to and from the RAM. This is where the data, applications and operating systems are stored on a temporary basis when currently being used by the user. They are also directly accessed by the processor. Just like Primary Memory if the operating system is turned off the data can be lost, (7)

DRAM â€"‘d Estands for ‘dynamic E DRAM is the most common of its type. It is mainly used due to the fact that it can hold large amounts of data in a small space within the computer. The downside is that is doesn’t retrieve its data again once the power supply turns off, therefore the data is lost proving it isn’t appropriate for long lasting storage. Once the power supply is gone it cannot store any data. The way DRAM is operated and proves guarantee that when the power supply is switched on it is certain that the data will be stored providing the power supply enables it to fill-up the cells. And in reverse there is no guarantee that even when the power does cut that all the data and information is fully wiped out. (21)

SRAM  Ethe ‘S Estands for ‘Static E This is a type of RAM which is used in many electronic applications. The content it has is only held while the power of the computer is applied. SRAM holds its data in a  Etatic Emanor where the data is kept until it is overwritten or is lost due to a loss of power. Unlike DRAM, SRAM is better on power when it is idle. (22)

ROM  Ethis type of memory acts as permanent memory. The data which is warehoused in the ROM cannot be manipulated. The information can be used on a ‘read-only Ebasis meaning that the data cannot be changed but only read. An good thing of ROM is that the program is always obtainable and ready to access memory and does not require any type of secondary storage device to open the data (i.e. Flash drive). The permanence; where data is always going to be available whether the system is turned off and the security, as the data cannot be easily adapted.

Cache  EA memory cache, sometimes called a cache store or RAM cache. It helps the CPU to access data efficiently and its information is stored in the RAM memory. A good thing about Cache memory is that, the more the memory is used the more the user is able to store extra information.

Registers  Ethis is a small type of memory that is used within the CPU. It is also known as one of the high-speed types of memory as it quickens the operation speed of the CPU. The registers allow the CPU to access the data or instructions which is currently stored within register. Just like RAM memory it is referred to as temporary memory because the data will stay on the system until it is on. There are four types of registers: one is which PC known as Program Counter which picks up the move instruction by using its address and loads the next instruction, IR known as Instruction register which holds the previous instruction; MAR known as Memory Address Register within the memory, it’s got the address of a location; and MBR known as Memory buffer register which it keeps the data that is being received and leaving from the memory instruction.

Secondary Storage

Secondary memory is used as permanent storage for data. It is able to hold vast amounts of data and does not get erased from the system memory. This means if the data is turned off the data is not lost. Like primary memory the secondary memory is not accessed directly from the CPU. Hard drives and optical disks are broadly used for secondary storage.

Although the time used for accessing data (i.e. reading and writing information) is quite slow compared to the primary memory, secondary memory devices have vital features that primary memory doesn’t have. The secondary memory is non-volatile this meant the data can be stored onto the secondary memory and can be accessed again even if the electric power is discharged from the secondary memory for example USB can store data on to it and can be used again in a different PC whereas RAM can only hold data as long as electric power is supplied. 

There are three different types:

Hard Drives - a hard drive is embedded within computer cases and laptops. It is an essential fragment of the computer as is stores all the data i.e. programs, images, videos, file, text file etc. External hard drives are also allowed to store material expanding the storage space through a back-up device (i.e. a USB). The information or data can be recovered easier from the hard disk.

Optical devices (CD/DVD’s) - CD or DVD drives are essentially used as part of all computer systems (17). They are designed to work with CD’s, DVD’s and Blu-ray disks. The data regained using a laser beam which reflects off the disk, detecting the pits.

Flash Drives  Eare also known as USB’s (Universal Serial Bus) is a transportable device which is inserted in a special USB slot in order for it to be used. (17). It can be used to store files such as images, songs, programs, setups, documentary files etc. The files on this device can easily be transferred from part of the computer to another, replace and taken off the device. (17). They are small devices and are available in different memory sizes from 64MB and 64GB.

Input and Output elements

Input and output element they used to provide information to the computer and outputs are used for displaying feedbacks from the computer. Without the input/output the computer is just an empty machine. These are the most common components used for communication between the computer and the user. They differ from size, price, capability and functionality. [17]

To/From the User

Keyboard: The keyboard is used for inputting information or data to the computer. The computer uses a different code for each character on the keyboard. The ASCII (American standard code for information interchange) binary code is recognised by all computers. When the user presses a key on the keyboard there is a capacitive switch in every character, this works when a circuit is completed, this results in keyboard sending a signal to a processor which interprets the signal and convey the key stroke your computer[6]

Mouse: Mouse is useful as the keyboard is but it has a different function. It gives user more interaction. A cursor which is displayed on the monitor and it’s controlled by the mouse. Cursor is only moved when it’s detected any kind of signals when the mouse is moved user. It has two buttons, one of the buttons allows user to select/click an object (icons) and the other button would allow other setting related to the object selected or in other word it would bring up more property to the object.

Monitor screen: Monitor screen allows computer to communicate with the user, the output devices convert computer code into information we can use. Without this output devices you cannot operate the computer.

Scanner  Escanners are used to capture image which has a primary form of a hard copy. E.g. a letter. The scanner looks at the amount of reflected light from all parts of the image and then converts the image from analogue values into digital pixels which creates a bit-mapped file. The computer allows the scanner to create a replicate of the image and is shown on the computer screen making it an electrical copy. This is usually used for cases where the user would like to have a back-up copy of an image or document which may be important or for personal uses.

There are three main categories of a scanner: a flat-bed; where the document or photo is put face down on the scanner glass plate where the image is scanned, hand-held; the user manually manoeuvres a hand held device across the document or image, and sheet-feed; where various amounts of documents can be fed through the scanner and be scanned onto the computer. (24) pg. 25)

Printer  Ea printer is an output device which is connected to a PC. The information that is usually transferred is text and graphics and is transferred on a standard sheet of paper, preferably A4 sized. The cost of printers can vary as they can be sometimes sold as a device that comes with a PC or is sold separately. (24) pg. 35)

When a software application produces a document which needs to be printed, it communicates with the printer in a way the printer will understand. This is acted through a printer ‘driver Ewhich is a device that acts as a communication interface between the computer and printer. Once the computer has communicated that it would like to print a document the printer will send feedback messages to ensure the user that their document has been successfully sent to the printer or if the printer is low on paper it will alert the user with a message on the screen to put more paper in the printer.

Laser printer  Ea laser printer uses a beam of light within the print head. A spinning multi-faced mirror guides the beam in a straight line along a rotating drum. The drum is shielded with a zinc oxide based film which has electrical properties which alter when it is clashed by light. (24) pg. 34)

Webcam  Ea webcam is a camera that is connected to the computer which generates images which is accessed and displayed using the World Wide Web server. The webcam can be connected to the computer either directly through a cable or wirelessly and obtains many images for remote display. Webcams are used by anyone and everyone and are used for many purposes depending on the user’s preferences.

The way in which webcams are used is through capturing tons of digital images that are transported between the computer and the server and then uploaded onto the main page. Webcam prices vary depending on their quality, capabilities and features. Their features vary through how many images they can pick up every second, some webcams can pick up one image every 30 seconds where as more up to date webcams can pick up at least 30 images per second making it a streaming video. Webcams are sold anywhere from retail shops which sell electrical good to online as well. (23)

Modem  Ethe word ‘modem Eis originated from the term modulator/demodulator. It is design to convert analogue signals into digital signals. Even though there it is usual for all data communication being digital, there times when it needs to be transformed from analogue to digital format. Telephone lines connections are used for some internet connections, these are through analogue signals. For a computer to process the large amounts of data the signals need to be transformed from analogue to digital signals. (24) pg. 73)

To/From the Network

NIC: Network Interface Card allow analogue signal to be converted to digital signal. Most of the motherboard the network card is built in. it allows computers to communicate between each other without the NIC computers cannot communicate. It uses protocols to transmit information or data.[18]

Graphics card allows computer to convert the binary numbers to objects for example image or text. Graphics cards give user better gaming experience, video editing, it will render image to the screen. The external card will be slotted in either PCI or PCI express that depends on the type of graphics card. Grapichs card has RAM they are also different type of RAM built in the card, the ranges from DDR to DDR5. The more RAM the Graphics card holds the more it allows it allow to render image.

Support Elements

Buses: Computer busses  Ewhen talking about a computer, the bus (12). For example, a bus allows a computer processor to communicate with the memory. There are two different types of busses Ean internal bus, also known as a local bus and an external bus also known as the expansion bus. The internal bus allows communication between the internal components such as the computer video card and memory and an external bus is able to communicate with external components such as a USB or SCSI device.

Cables: Cables are used to connect other devices which can communicate with motherboard. Hard drive communicate with the motherboard by using cables this cable is called IDE short for integrated Drive Electronics. Todays Eday and age, this type of cable are not used for connecting hard drive or CD drive but still found on most motherboard. SATA knows as SerialATA is mostly used for connecting hard drive or CD drive it’s much faster and smaller.[19]

Case: Computer Case allows protection for computer components and also is used for air circulation. The case designs are made so the air can go in and out from the back of the case. This would allow CPU fan to intake air from outside the case which then can keep the CPU cool and prevents from overheating. There are different types of cases which are designed for different type of motherboards.

Motherboard: The motherboard provides the need of means for all the components and peripherals in the computer to communicate with each other. The motherboard is made up of connectors which attach other boards with each other, these other component are which makes computer fully working. For example CPU,BUS,Serial And Parallel ports and for graphic card/sound card(MIDI) there are expansion slots. There are ports like (SATA) to connect hard drive or dvd/cd drive or ports that will allow other peripheral devices Other existing motherboards allow data to run faster and efficiently among the components stated with advances technologies. PCI(32-bit or 64bit) or ISA (8 or 16 bit) the more bit it has the more the mortherborad is capable of processing data. If it has 8 bits that means it will process 8 bits in one cycle. In this day and age the typical motherboard usually uses PCI. There is also a different of bus which is known as AGP (Advanced Graphics Port) although these types of ports are only used for video cards. Both the PCI and AG components combined together, as they both provide different slots and the PCI or AGP components or motherboards will always transmit data up to four times faster than a normal component. (13)(14)

Heat-sinks: Heat-sinks/Fan 15). There are two different types of heat sinks; Active and Passive. Active heat sinks apply power and are very often a kind of fan or another type of cooling device. These types of heat sinks can also be referred to as HSF, heat-sink allows heat to be cool down from the CPU chips and also they are 100% trustworthy, as they have no complete mechanical components. They are made up of (3). In order for heat sinks to do their job to their fullest ability it is suggested that there is firm air flowing between the fans. (15)

Power supply: Power Supply Unit PSU  Ethis is an element that gives power to a computer. The power supply generates the essential amount of Voltage and converts to Alternating Current also known as AC) into Direct Current which is knows as DC. (16)Power supplies relate to the amount of watts that are generated. (16)

Conclusion

The computer technology is keeps expanding due to the demands. Nowadays computer are used everywhere and also found, for example cash machine or ticket machine. It makes life much easier for the humans computer can do a lot more a human can.

Programmers develop software Efor blind people for example a blind person can still use the computer by have a Braille keyboard and voice reader. When the person presses the button the speakers would read out the character been pressed .The world is becoming a lot more advanced with its technology on a daily basis as more and more devices will become more advanced.