Question

1. Review the computer system 1. Please provide a definition for the following terms a. Computer b. Program c. Programming language d. Algorithm e. ROM f. RAM g. Cache Memory h. Computer Architecture

Answer 1

COMPUTER

• A computer is an electronic device,operating under the control of instructions stored int its own memory that can accept data(input),process the data according to specified rules ,produce information (output),and store the information for future use.
• FUNCTIONALITIES OF A COMPUTER
• 1)Takes data as input
• 2)Stores the data/instructions in its memory and use them when required
• 3)Process the data and convert it into useful information
• 4)Generates the output
• 5)Controls all the above four steps
• COMPUTER COMPONENTS
• Any kind of computer consists of HARDWARE AND SOFTWARE
• HARDWARE
• Computer hardware is the collection of physical elements that constitutes a computer system.Computer hardware refers to physical parts or components of a computer such as monitor,mouse,keyboard,data storage,hard drive disk,system unit ,etc all of which are physical objects that can be touched.
• SOFTWARE
• Software is a generic term for organized collections of computer data and instructions,often broken into two major categories:system software,application software
• 1)SYSTEM SOFTWARE
• It is responsible for controlling,integrating and managing the individual hardware components of a computer system so that other software and the users of the system see it as a functional unit without having to be connected with the low-level details.Generally system software consists of operating system and some fundamental utilities such as disk format,file managers,display managers,text editors,login and management tools.
• 2)APPLICATION SOFTWARE
• It is used to accomplish specific tasks other than just running the computer system.Applications software may consists of a single program,such as image viewer;a small collection of programs that work colsely together to accomplish a task;such as spreadsheet or text processing system
• COMPUTER CLASSIFICATION
• Computers can be classified by size and power as follows,
• 1)PERSONAL COMPUTER:       A small single-user computer based on a microprocessor.In addition to the microprocessor, a personal computer has a keyboard for entering data,a monitor for displaying information,and a storage device for saving data.
• 2)WORKSTATION : A powerful,single-user computer,A workstation is like a personal computer, but it has a more powerful microprocessor and a higher-quality monitor.
• 3)MINICOMPUTER: A multi-user computer capable of supporting from 10 to hundred of users simultaneously.
• 4)MAIN FRAME: A powerful multi-user computer capable of supporting many hundreds or thousands of users simultaneously.
• 5)SUPER COMPUTER: An extremely fast computer that can perform hundreds of millions of instructions per second     
• CHARACTERISTICS   OF A COMPUTER
• 1)Speed
• 2)Accuracy
• 3)Diligence
• 4)Storage capability
• 5)Versatility        

     

PROGRAM

• An organized list of instructions that when executed causes the computer to behave in a predetermined manner ,Without programs computers are useless
• A program is like a recipe,It consists a list of ingredients (called variables) and list of directions(called statements) that tell computer what to do with the variables.The variables can represent numeric data,text,or graphical images
• There are many programming languages---C,C++,PASCAL,BASIC
• Every program must be translated into a machine language that computer can understand.This translation is performed by compilers,interpreters,assemblers.
• When you buy a software you normally buy an executable version of a program.This means that the program is already in machine language--it has already been compiled and assembled and is ready to execute.

PROGRAMMING LANGUAGE

• The code is pretty much like writing a paragraph of instructions or creating a to-do list to computers.Unlike humans ,the to-do list and instructions you write for the computer has to be extremely detailed and written in some logic.With code and programming ,you can get the computer to draw complex shapes and create rich computer graphics, and then create programs that understand game mechanics and help you buikd games that feel real gravity and partile collision.
• With code you can create and send content all over the world with your blog and personal website and style your blog to meet your style.
• With code and programming you can create smart home applications,like an automated peet feeder,a smart mirror or even create a robot that can help around with household tasks
• USES OF PROGRAMMING LANGUAGES
• WEB DEVELOPMENT:    If you are interested in building websites there are two intertwining parts to look into:
• 1)Front -End Development :which creates the application that runs on your browser and adjusts the styling,the colors,interactions.Ex:HTML,CSS,JAVASCRIPT.
• 2)Back-End Development:    which is related to the server,the computer that runs the website software and serves it to the world.It's mostly concerned with routing,which pages to deliver to the user when they visit a certain URL,it also communicates with the data base that stores the websites information and sends data over to use.Ex:PHP,RUBY,C#,PYTHON,ELIXIR.
• GAME DEVELOPMENT: Creating game requires what's called a game engine,which is a software that is used as the infrastructure for building the game and defines what the game has and what it can do.Ex:C++,C#,JAVA,LUA.
• MOBILE DEVELOPMENT: Creating mobile applications is a little tricky,as there is more than one OS for mobiles.Android is most commonly used in Samsung while IOS is used in Apple.To create Android apps you'd need wither JAVA or KOTLIN,and for creating IOS applications you'd need Objective-C or SWIFT.
• LEARNING A PROGRAMMING LANGUAGE: Learning programming languages primarly requires dedication and practise ,you can not become a programmer without writing code.

ALGORITHM

• The word Algorithm means "a process or set of rules to be followed in calculations or other problem-solving operations.Algorithm refers to a set of rules/instructions that step-by-step define how a work is to be executed upon in order to get the expected results.
• In order for some instructions to be an algorithm it must have characteristics:
• 1)Clear and Unambiguous
• 2)Well-Defined Inputs
• 3)Well-Defined Outputs
• 4)Finite-ness
• 5)Feasible
• 6)Language Independent
• ANALYSIS OF AN ALGORITHM
• 1)Prior Analysis:   Prior means before.Hence prior analysis means checking algorithm before its implementation.This is done usually by the algorithm designer.
• 2)Posterior Analysis:   Posterior means after.Hence it means checking the algorithm after its implementation.In this the algorithm is checked by implementing it in any programming language and executing it.
• FACTORS OF ALGORITHM COMPlEXITY
• 1)Time factor: Time is measured by counting the no.of key operations such as comparisons in the sorting algorithm.
• 2)Space factor: Space is measured by counting the maximum memory space required by algorithm.

RAM( Random Access memory)

• It is a part of computers Main Memory which is directly accessible by CPU.RAM is used to read and write data into it which accessed by CPU randomly.
• RAM is volatile in nature,it means if the power goes off,the stored information is lost.
• RAM is used to store data that is currently processed by the CPU.
• There are two types of RAM chips
• 1)SRAM(Static RAM):    the SRAM memory consists of circuit of retaining the stored information as long as power is applied.That means this type of memory requires constant power.Cache memory is made up of SRAM chips.
• 2)DRAM(Dynamic RAM):   it stores the binary information int the form of electric charges that applied to capacitors.The stored information on the capacitors tend to lose over a period of time and thus the capacitors must be periodically recharged to retain thei usage.The Main memory is made up of DRAM chips.

ROM(Read only memory)

• Unlike RAM, in ROM the binary information is stored permanently.Once it is stored ,it remains within the unit ,even when power is turned off and on again.
• CLASSIFICATION OF ROM
• 1)Mask Rom:
• 2)PROM(PROGRAMMABLE ROM)
• 3)EPROM(ERASABLE PROGRAMMABLE ROM)
• EEPROM(ELECTRICALLY ERASABLE ROM)
• FLASH ROM

CACHE MEMORY

• Cache memory is a special very high-speed memory.It is used to speed up and synchronizing with high-speed CPU.Cache memory is costlier than main memory or disk memory but economical than CPU registers.Cache memory is an extremely fast memory type that acts as a buffer between RAM and CPU.
• It holds frequently requested data and instructions so that they are immediately available to the CPU when needed.
• Cache memory is used to reduce the average time to access data from the Main memory.
• When the processor need to read or write a location in main memory ,it first checks for a corresponding entry in the cache
• If the processor finds that the memory location in cache ,a CACHE HIT has occured and data is read from cahce
• If the processor does not find the memory location in cache ,a CACHE MISS has occured. The cache allocates a new entry and copies in data from main memory,then the request is fulfilled from the contents of cache.
• Performance of cache is cache hit ratio.
• Hit ratio=hit / ( hit   + miss )
• There are three different types of mapping used for the purpose of cache memory which are as follows
• 1)DIRECT MAPPING
• 2)ASSOCIATIVE MAPPING
• 3)SET-ASSOCIATIVE MAPPING
• TYPES OF CACHE
• 1)Primary cahe
• 2)secondary cache

COMPUTER ARCHITECTURE

• It is science or a set of rules stating how computer software and hardware are joined together and interact to make a computer work
• It determines which technologies the computer is capable of,
• computer architecture consists of three main categories:
• 1)System design :includes all hardware parts such as CPU,data processors,memory controllers and memory access.
• 2)Instruction set Architecture :   includes CPU functions and capabilitis ,the CPU programming language,data formats,processor register types and instructions used by programmers.
• 3)Microarchitecture :Defines the data processing and storage delemt or data paths and how they should implemented into the instruction set architecture .Yhese might include DVD storage devices or similar devices.