Computer Systems Components and Software - PDF

,Unit 1 - types & components of comp systems!!! (crash out simulator) Hardware type shiii!! There’s hardware AND software daughterboard betcchhh b)​ Central processing unit (CPU)/processor -​ There's another fucking subunit on this! -​ Electronic circuit board in comp tht exe...

,Unit 1 - types & components of comp systems!!! (crash out simulator) Hardware type shiii!! There’s hardware AND software daughterboard betcchhh b)​ Central processing unit (CPU)/processor -​ There's another fucking subunit on this! -​ Electronic circuit board in comp tht execute cmd from comp program -​ 2 main components: ALU (arithmetic logic unit) - do the math and logic operations, control unit (CU) - decode and execute cmds c)​ Random Access Memory (RAM) -​ Internal chip, data temp stored there when running application -​ Memory CAN BE WRITTEN TO AND READ FROM -​ “Volatile/temporary memory” - contents lost when comp shutdown -​ Stores data/files/parts of OS currently in use d)​ Read Only Memory (ROM) -​ Memory to store permanent info -​ Oftn used contain config data for comp sys (e.g. BIOS) -​ Chips can’t be altered, ONLY BE READ FROM  -​ Advantages - data stored in ROM is not lost when power turnoff (shutdown) -​ ALWAYS CALLED NON VOLATILE MEMORY e)​ Graphics card/Video card/VIDEOGRAPHICS CARD (VGA) -​ Allows comp to send graphical info -> video display dv e.g. monitor tv projector -​ Usually connect 2 motherboard -​ Usually made of: -​ Processing unit -​ Memory unit usually RAM -​ Cooling mechanism (often in form of heat sink cz generate heat) -​ Connection to display unit f)​ Sound card -​ Integrated circuit board -​ Provide comp w/ ability to prod sounds -​ Allow user to rec sound input frm mic connect to comp, & manipulate sounds stored on disk -​ FM synthesis -​ Wavetable synthesis g)​ Network Interface card (NIC) -​ Component tht allow comp/ any other dv to connect to network (internet) -​ NOT ALLOW ACCESS TO WORLD WIDE WEB -​ Can be wired/wireless -​ Each NIC - hard coded w/ unique MAC (media access control) address h)​ Internal storage devices (hard disk drive, solid-state drive (SSD)) -​ HDD magnetic in nature, 1 of main method to store data/files/most of sys and app files -​ SSD tech r newer storage sys -​ Function same as HDD, replace HDD in many cases Software -​ General term for prgrm tht control comp sys & process data -​ 2 categories: a)​ Application software b)​ System software Application software (8) -​ Program tht allow user to perform spec tasks A.​ Word processor -​ To mani text in doc e.g. essay/report -​ Text entered w/ keyboard. Sw prov tool for copy/del & diff types of format -​ Formatting example: bold, italic, underline, change font size/type -​ Tools: copy&paste, spell checker, thesaurus, translation into diff lang, create/edit/save/mani text, import photo/img into struct. pg fmt B.​ Spreadsheet -​ To org n mani numerical data (integer, real, date, etc.) -​ Num org on grid of lettered column, numbered row -​ Grid made of cells, cell identify by column letter row number -​ Functions: -​ Use of formula to carry out calc -​ Can prod graph -​ Can do modelling & hypothetical calc C.​ Database -​ Org mani and analyse data -​ Normally made of 1/1+ tables, consist of rows (record) and columns (field) -​ Functions: -​ Can carry out queries on database data & prod report -​ Add, del n mod data in a table Control and measuring software -​ Design to allow comp/microprocesser to interface w/ sensor so can: -​ Measure physical quantities in real world e.g. temp -​ Control applications e.g. green house control -​ Compares sensor data w/ stored data & send out signal to change process output Apps and applets -​ Short for application -​ Typr of software tht run on mobile phone/tablet -​ Usually downloaded from App Store, games/complex software e.g. phone banking, GPS, camera facilities, video n music streaming Photo editing software  -​ Lets user mani digi photo stored on comp -​ E.g. change brightness/contrast/saturation, remove red eyes -​ Also complex mani like change facial features, combo photo Video editing software -​ User can mani vid to prod edited vid -​ Enable adding of titles, colour correction, adding/altering sound to og vid -​ Rearranging, add, or remove section of video clip and audio clip -​ Apply colour correction, filters, other vid enhancements -​ Create transition btw clip in vid footage Graphics manipulation software -​ Allow bitmap & vector image to be changed -​ Measured in DPI (dots per inch) - the higher the DPI, the higher the resolution, the clearer the picture. But disadvantage - larger file -​ Type of editing software depend on fmt of og img 1.​ Bitmap -​ Images made up of pixels tht contain info abt img brightness n colour -​ Bitmap graphic editor can change pixels to prod diff image -​ Disadvantages: may look distorted and low quality when the bitmap img is enlarged/shrunk, large file size 2.​ Vector -​ DO NOT USE PIXEL -​ Mani line curve and text to change stored img Systems software -​ Program tht allow hardware to run properly, allow user to comm with comp Computer language: a)​ Machine code -​ Programming lang tht can be directly understood by comp n obeyed w/o need for translation -​ Diff for each CPU, native binary lang made of 0 and 1, difficult to read b)​ Assembly level language -​ Or assembler lang, often abbreviated as asm -​ Low-level programming lang for comp/other programmable dv  -​ 1-to-1 correspondence btw lang and machine code instruct c)​ High level language -​ More “english-like” lang, used to write program by programmer -​ Enable programmer to write program independent of computer type -​ High lvl cz closer to human lang, less like machine lang -​ HLL is then translated into LLL by assembler, compiler or interpreter -​ Easier to understand and read but comp cannot understand 1.​ Compiler -​ Comp prog tht translate prog written in HLL into machine code (code tht comp can understand cz it retard) so it can be used by comp to perform req task -​ OG program - source code -​ Code after compilation - obj code -​ Once compiled code can be used again n again w/o recompilation -​ E.g. HLL: Java, Python, C++ 2.​ Linkers/link editor -​ Comp prog tht take 1+ obj file made by compiler, combo them into 1 program tht can be run on comp -​ E.g. many module made by diff programmer on diff dv, linker put all modules tgt to make final program. 3.​ Device driver -​ Sw tht enable 1+ hw dv to comm with comp OS -​ w/o driver hw unable to work w/ comp -​ Once hw connect to comp thru usb port -> OS look for suitable driver -​ Error msg popup if cannot find 4.​ Operating system -​ SW running in bg of comp sys -​ Manage many basic instructions, allow:  -​ Users an interface to comm with comp -​ Loading and running of programs to happen -​ Managing of security (user acc, log on password) -​ More later lol 5.​ Utility software -​ Designed to carry out specific task on comp -​ Programs tht help to manage, maintain & control comp resource -​ Example: a)​ Antivirus b)​ Anti-spyware c)​ Fire backup d)​ Disk repair e)​ File management f)​ Security g)​ Screensavers h)​ Disk defragmenter i)​ Encryption/decryption Analogue and digital data a)​ Digital data -​ Computer can only understand data in binary format (0,1) -​ Called digital data cz only DISCRETE, DISCONTINUOUS values e.g. 1,4 b)​ Analogue data -​ Data in the real world - analogue -​ Physical data tht changes smoothly frm 1 value to the next, continuous -​ E.g 0-6, an infinite number of values can exists like 2.345, 5.6…] If analogue data sent to comp - must be converted to digital format, use hw known as an analogue-to-digital converter (ADC). Output from computer -> convert by digital-to-analogue converter (DAC) Main components of computer sys Input devices Keyboard, mouse, camera, mic, sensor, scanner Output devices Monitor, printer, speaker, projector Secondary storage devices Hdd, ssd, pen drive. -​ Internal hw - 4 main components:  a)​ CPU, central processing unit b)​ Internal hard disk drive/solid state drive (backing storage) c)​ Random access memory (internal memory) d)​ Read only memory (internal memory) CPU -​ Part of comp tht interpret n execute cmd frm comp hw and sw -​ Used to be made of discrete components n many small integrated circuits, now cz of modern manu, CPU now referred to as MICROPROCESSOR -​ Microprocessor - single integrated circuit at core of most PCs. found in many household devices n equipment where control n monitoring needed -​ E.g. washing machine, microwave, dishwasher, fridges -​ Components: a)​ Control unit, CU -​ cntrl input output dv -​ Extract instruction frm memory, decords n execute them -​ Calls on ALU if necessary, comm with both ALU n memory b)​ Arithmetic and logic unit, ALU -​ Carry out calc n make logical decision c)​ Memory unit -​ Principal storage of comp -​ All data n instructions tht comp need @ moment r store here -​ INCLUDE HDD, SSD, RAM, ROM. Internal memory (RAM N ROM)  -​ ROM usually hv config data for comp sys -​ ROM also got some coding - BOOT FILE -​ Tells comp what to do when it first start up -​ Often called BIOS (basic input/output system) -​ When comp turn on -> BIOS carry out hw check, find if all dv present and functional -​ Then loads OS into RAM -​ Stores date, time, system config in a non-volatile chip called a CMOS (complementary metal oxide semiconductor) -​ Usually battery powered Input & Output devices a)​ Input devices -​ Hw tht allow data to be entered into comp -​ Use manual entry (keyboard, mouse)/direct data entry (sensor) -​ Make input into form comp understand -​ Mouse make hand movement into cursor movement -​ Sometimes need adc, e.g. sound from mic go tru adc ->comp b)​ Output devices -​ Comp process data -> human wna see results of processing -> output dv -​ Display comp result in form human understand, e.g. prntr text, monitor img -​ Some dv both input output, e.g. touch screen, DVD writer/player. Most dv either 1 -​  -​ Similarities: both provide user interface btw comp, both hardware, both power Backing storage -​ Main memory in comp - RAM, ROM -​ Backing storage - to perm store large amt of data -​ Internal hard disk drive (HDD) / solid-state drive (SSD) -​ Main internal storage where application sw, disk OS, files (text, photo, music) r stored -​ STORES DATA PERMANENTLY!!! NON-VOLATILE!! -​ Data access time/rate - how fast open file, dta transfer rate - how fast data is saved frm ram to hard disk (backing storage) Internal memory Backing storage RAM contents are lost when Backing storage devices hold their contents computer is powered down; ROM permanently, even when powered down. contents are readable only. RAM and ROM are much smaller Have considerably larger capacity to store data memories than backing storage. than RAM or ROM (cheaper mah) Data access time on RAM and Has much slower data access time than RAM or ROM is extremely fast (can be ROM. read direct by cpu) Much more expensive per byte Is much cheaper per byte than RAM or ROM. than backing storage devices. RAM and ROM are fixed inside Backing storage can either be fixed (external or the computer (internal internal) or it can be removable (e.g external HDD, memories). ex SSD, Blu-ray disc). Advantage: can be used as backup incase of dataloss/corruption - data frm hdd/ssd can be copy onto another dv (pendrive, etc.) then stored in separate location -> og data lost, then u still got backup what RAM and ROM can be read B4 data on a backing storage device can be read directly by the CPU. by CPU,must b moved into RAM; backing storage not directly addressable by the CPU. Operating sys a)​ Control of op of input output n backing storage dv b)​ Supervise loading running n storage of application sw  c)​ Deal w/ error in applic. program d)​ Maintain security of whole comp sys e)​ Mntn comp. log f)​ Allow comm between user n comp sys by acting as an interface. USER INTERFACES!!!! Fuck a)​ Command Line Interface CLI -​ Req user to type in instruct to choose option frm menu, open sw, etc -​ A lot of cmd to type in e.g. save/load file -​ Windows CLI - command prompt -​ Possible to alter comp config settings, typing in 1 by 1 take time -​ Uses: -​ Programmers may use to have unrestricted access to computer cmd to make new sw -​ Technician use it to locate errors easily to del them b)​ Graphical user interface GUI/WIMP user interface -​ User interact w/ comp using icons instead of typing in cmd -​ Select icon -> auto execute cmd in GUI, no need to type -​ Use WIMP (windows icons menu n pointing dv) for personal comp (PC) -​ Mouse control cursor, icon select to open/run windows -​ Each window - hv applic. Modern times can hv many window open -​ Window manager manage interaction btw windows, applic n window sys (handle pointing dv n cursor position) -​ Touch screen smartphone/tablet - ‘post-WIMP’ interaction -​ Finger in contact w/ screen  -​ Allow pinching, rotating -​ Uses: -​ Students use to do homework -​ Gamer use it to play games that don’t require any special cmds c)​ Dialogue-based user interface -​ Use human voice to giv cmd to comp sys -​ Smart dv asked ques by human, human voice converted to binary stream with ADC, compares the spoken word to cmds stored in database, smart device process cmd n output analogue verbal response n what user ask it to do -​ E.g. google home, alexa, cortana… -​ Examples: i) “smart home” where user can control temp, light, curtains by spoken cmds, good for disabled people ii) a driver use it to give commands without leaving the steering wheel in a voice-activated car d)​ Gesture-based user interface -​ Rely on human interaction - moving of hands, head, feet -​ Allow human a more natural interface, no nid mechanical dv -​ Use technique - computer vision n img processing -​ The sensor or camera connected to the computer captures an image of the gesture being performed and send a signal to the computer. It compares it to saved gestures in the database then outputs the desired command -​ Examples: -​ Moving hand near window open window -​ Doctor in sterile environment can use to interact w/ dv w/o spreading germs -​ Change music playlist w/o touching screen Types of computers a)​ Desktop -​ General purpose comp -​ Made of separate components - monitor, keyboard, mouse, cpu, not portable like laptops -​ Advantages a)​ Spare parts n connections standardised, lower cost SO easier n cheaper to upgrade/expand b)​ Have better specification e.g. better cpu for price, not limited by size/portability concern c)​ Power consumption not critical - plug nto wall socket, large casing let heat dissipate nicely d)​ Less likely to be dmg/ stolen cz fix in 1 position e)​ Internet access more stable - hardwired internet connection e.g. ethernet, signal varies less than wireless so data transfer r8 bttr -​ Disadvantages a)​ Not portable - several components b)​ SO u hv to copy files to a memory stick if u wna work elsewhere/cloud storage c)​ More complicated, all components hooked up by trailing wiring -> cluttr -​ Uses  -​ Office and business work - word processing, sprdsht, databse, etc -​ Education use - interact sw to teach -​ Gaming device: chess, video game -​ General entertainment (netflix etc) b)​ Mobile laptops A)​ Laptop computers -​ Comp where monitor, pointing dv, processor unit, battery unit all combo in 1 dv -​ Features: lightweight n portable, low power consumption, low heat output, internal battery -​ Advantages -​ Self-contained so portable w/ no trailing wires -​ Lower power consumption than desktop -​ Can be used anywhere w/ Wi-Fi hotspot & link to any multimedia sys -​ Disadvantages -​ Easier to break/steal cz portable -​ Limited battery life or need to caryr heavy adaptor -​ Keyboards n pointing devices e.g trackpad can b awkward to use -​ Not always possible to upgrade cz self contained, hard to take apart -​ Main uses -​ Offine n biz work - spreadsheet, database, wrdproecssing -​ Control & monitoring - laptop portable, possible to use to gather data directly from environment w/ min setup -​ Education use -​ Gaming device -​ General entertainment B)​ Smartphone -​ have OS e.g. android, windows -​ Run alot of comp application called apps/applets -​ 4G/4G/5G cellular networks or wifi to connect to internet for phone calls n send messages -​ Features:  -​ High-definition, anti-glare displays -​ Front n back facing cameras -​ Lighter and longer battery life than laptop -​ Bluetooth to connect to printer and other devices -​ Many sensors: a)​ Proximity sensor - detect if dv close to smt to block unintended action by touch b)​ Accelerometer - detect movement, orientation of dv c)​ Sophisticated speech rec sys - let the user ask dv to look for things, e.g. setting an alarm -​ Advantages -​ Small and lightweight, easy to carry arnd -​ Use to make phone call but also connect to internet -​ Can be used almost anywhere cz use wi-fi and mobile phone network -​ Reasonable battery life compared to laptops -​ Apps tht make use of sensor data available, e.g. location data for maps - not avail on laptops -​ Disadvantages -​ Small screen n keyboard make pgs difficult to read -​ SO harder and slower to type tings in -​ Web browsing n photography quickly drain battery -​ Not all website features compatible -​ Easier to steal cz small -​ Data transfer r8 w/ cellular network slower than wifi -​ OLED -​ Organic light emitting diode touch screen -​ Allow phones to be thinner and lighter -​ OLED covered w/ crystalline layer - partially solar powered, can use Li-Fi -​ Li-Fi -​ Like wifi but comm thru visible light -​ Advantages: -​ Faster than wifi, higher data transfer r8 -​ More secure, stops internet piggybacking -​ Can be used on airplane flights - do not use radio waves tht interfere with flight controls sys  -​ Use: -​ Hospitals - to monitor patient condition in real time -​ Underwater communication - divers can easily comm with vessel above water/ themselves -​ Vehicles - can use fronts n back LED lgihts to comm with other sys like traffic light, can prevent accidentsss C)​ Tablet -​ Similiar to smartphone -​ Features -​ Touch screen technology, on-screen virtual keyboard (activated by touch w/finger/stylus) -​ Front n back facing camera -​ Many sensor - accelerometer, proximity sensors, etc -​ Advantages -​ Quick to switch on, no need wait for os, portable -​ Touch screen ez to use w/o need 4 other input dv -​ Longer battery life -​ Can use several standard applications w/o generating much heat, solid-stated tech, e.g. camera, mp3/4 player -​ Tablet -​ More expensive than laptops -​ Limited memory and storage compare to laptops -​ Typing on touch screen slow n easily error -​ Support less file formats, may not be able to run certain software -​ If cellular network used, can be expensive to run if accessed frequently -​ File transfer thru application store, can be annoying - no drap and drop -​ Entertainment, for video streaming -​ Educational use, to write interactive digital notes -​ Gaming, to play simple games such as chess D)​ Phablet -​ Hybrid between tablet n smartphone -​ Larger screen than smartphone but smaller than tablet  -​ Front n back facing camera, touchscreen tech w/ onscreen keyboard, many sensors, bluetooth, etc… all features of tablet n phone -​ Advantages -​ Easier to read/browse than phone -​ Longer battery life than phone -​ More compact than tablet -​ Disadvantages -​ Larger screen makes it awkward to take phone calls -​ More expensive -​ Harder to use one-handed than phones -​ Uses Ref to bottom Main uses of smartphones tablets and phablets a)​ Instant messaging b)​ As a camera or video camera c)​ Internet use for online shopping, social networking, using QR codes d)​ Educational use - using interactive sw to teach/learn from e)​ Remotely control devices at home w/ embedded microprocessors i)​ Examples -​ Microwave -​ Washing machine -​ Air-conditioning -​ Oven ii)​ Advantages -​ Convenient to access from a distance js by using application -​ Less heavy to carry around than a laptop to control dv at home iii)​ Disadvantages -​ Works only when u got internet -​ Less secure - dv connect to internet, accessible to hackers, may ruin home/devices -​ Dv collect personal data for it to function so hackers online can mayb steal ur data Emerging tech - Artificial intelligence -​ Machine or application tht carries out task th req some degree of intelligence, -​ Use of language -​ Recognizing someones face -​ Ability to operate machinery such as car and train -​ Analysing data to predict outcome like weather forecasting -​ Positive impacts -​ Improvements in safety - AI r able to carry out tasks like bomb disposal unlike humans who can die permanently from it -​ Better quality of products -​ Faster development of products - AI work 24/7 -​ Autonomous vehicles e.g. self driving cars -​ Negative impacts -​ Can lead to unemployment in many areas - create job loss for clerks, etc -​ Humans will develop a dependence on AI, leading to loss of skills e.g. data entry, problem if AI were to fail 1 day -​ Suspicion that machines are taking over??? Extended reality -​ Combination of real and virtual environments, term for all immersive tech a)​ Augmented reality, AR -​ User exp relationship btw digital n physical worlds -​ Not isolated frm real word, can interact n see what infront of dem -​ Virtual data n obj overlaid onto real world, e.g. imgs, text, anim -​ Experience thru special goggles/smartphone/phablet screen -​ Example: pokemon go, overlays chara onto irl screen -​ Impact of AR: -​ Entertainment: ur favourite game characters can be seen in your home n can be interacted with -​ Shopping n retail: can try out clothes and makeup digitally b4 buy -​ Safety & rescue; 3d img of crime scene can allow detective more time to figure out what happen w/o need to go to the scene itself -​ Healthcare- dr use it to build 3d img of patient for diagnoses b)​ Virtual reality, VR  -​ Technology is able to take the user out of the real world into a virtual environment -​ Immersive experience. Fully in digital world -​ User wears a VR headset, 360 degree view of virtual world, tricks brain into thinking they r actually at tht place -​ Impacts: -​ Military - soldiers can be trained in a virtual high risk situation to operate tanks without risk of casualty -​ Healthcare - as a diagnostic tool to reccomend treatment -​ Entertainment e.g. first person shooter games where the user is in the battlefield themselves -​ Business e.g. role playing and training scenarios for staff -​ Media - e.g. interactive sfx -​ Scientific visualisation / engineering / sport / fashion / heritage c)​ Mixed reality, MR