01-04-2020-Oxford_English_for_Infomation_Technology (1171844), страница 6
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What do you think it means?Operating Systems: Hidden SoftwareNow read this text to check your answer and to find the answers tothese questions:1What difference is there between applications software andoperating systems?2 Why is the supervisor program the most important operatingsystem program?3 What is the difference between resident and non-residentprograms?4 What are the main functions of an operating system?When a brand new computercomes off the factoryassembly line, it can donothing. The hardware needssoftware to make it work. Arewe talking about applicationssoftware such aswordprocessing or spreadsheetsoftware? Partly.
But anapplications software packagedoes not communicate directlywith the hardware. Betweenthe applications software andthe hardware is a softwareinterface - an operatingsystem. An operating system isa set of programs that liesbetween applications softwareand the computer hardware.The most important programin the operating system, theprogram that manages theoperating system, is thesupervisor program, most ofwhich remains in memory andis thus referred to as resident.The supervisor controls theentire operating system andloads into memory otheroperating system programs(called nonresident) from diskstorage only as needed.An operating system has threemain functions:managethe computer's resources, suchas the central processing unit,memory, disk drives, andprinters,establish a userinterface, andexecute andprovide services forapplications software. Keep inmind, however, that much ofthe work of an operatingsystem is hidden from theuser.
In particular, the firstlisted function, managing thecomputer's resources, is takencare of without the user beingaware of the details.Furthermore, all input andoutput operations, althoughinvoked by an applicationsprogram, are actually carriedout by the operating system.38UNIT 6 Operating SystemsComplete the gaps in this summary of the text on operatingsystems using these linking words and phrases:althoughbecausebutin additionsuch asthereforeThe user is aware of the effects of different applications programsoperating systems are invisible to most users. They liebetween applications programs,wordprocessing, and thehardware.
The supervisor program is the most important. It remainsin memory,it is referred to as resident. Others are callednon-residentthey are loaded into memory only whenneeded. Operating systems manage the computer's resources,the central processing unit., they establish auser interface, and execute and provide services for applicationssoftware.input and output operations are invoked byapplications programs, they are carried out by the operating system.LANGUAGE WORK-ing form (1) as a noun; after prepositionsWe can use the -ing form of the verb as anoun. It can be the subject, object, orcomplement of a sentence. For example:The -ing form is also used after prepositions.This includes to when it is a preposition andnot part of the infinitive.
For example:14Managing the computer's resources is animportant function of the operatingsystem.2 The operating system starts running theuser interface as soon as the PC is switchedon.3 Another function of the operating systemis executing and providing services forapplications software.Without the user being aware of the details,the operating system manages thecomputer's resources.5 We begin by focusing on the interactionbetween a user and a PC operating system.6 We look forward to having cheaper andfaster computers.UNIT 6 Operating Systems39Rewrite each of these sentences like this:An important function of the operating system is to manage thecomputer's resources.Managing the computer's resources is an important function ofthe operating system.1One task of the supervisor program is to load into memory nonresident programs as required.2The role of the operating system is to communicate directly withthe hardware.3One of the key functions of the operating system is to establish auser interface.4An additional role is to provide services for applicationssoftware.5Part of the work of mainframe operating systems is to supportmultiple programs and users.6The task in most cases is to facilitate interaction between asingle user and a PC.7One of the most important functions of a computer is to processlarge amounts of data quickly.8The main reason for installing more memory is to allow thecomputer to process data faster.Complete these sentences with the correct form of the verb:infinitive or -ing form.12345678Don't switch off without (close down) your PC.I want to (upgrade) my computer.He can't get used to (log on) with a password.You can find information on the Internet by (use) a searchengine.He objected to (pay) expensive telephone calls for Internetaccess.He tried to (hack into) the system without (know) the password.You needn't learn how to (program) in HTML before (design)webpages.I look forward to (input) data by voice instead of (use) akeyboard.40UNIT 6 Operating SystemsPROBLEM-SOLVINGTry to find the commands from the lists below which will havethese actions.VMShelpdirectorysearchcopyrenameprintshow usersshow timecreate/directoryphonedeleteUnixwritecpIprIsmkdirdatermmangreprwhomvActionVMS commandUnix commandList all the files in a directoryDelete a fileRename a fileCopy a fileSend a file to a printerObtain helpCreate a directoryShow date and timeShow users on systemTalk to other users on systemSearch for a string in a fileSPEAKINGWork in pairs, A and B.
Each of you has information aboutsome popular operating systems. Find out from the information youhave and by asking each other, the answers to these questions:Student A Your information is on page 184.Student B Your information is on page 190.1 Which operating system is used on Apple Macintoshmicrocomputers?2 What is Penpoint designed for?UNIT 6 Operating Systems34567Name one system used on IBM mainframes.Which operating system is Linux related to?Name an IBM operating system similar to MS-DOS.Which operating system replaced MS-DOS?Which systems are in fact graphically orientated shells for MSDOS?8 How many versions of Windows 9X were developed?9 Which operating systems are designed for networks?10 Which operating system is used by DEC VAX minicomputers?WRITINGThis description of the Mac OS X is drawn from the tablebelow.
Write a similar description of Linux.Mac OS X is a Unix-based operating system designed for use on AppleMac computers. It includes memory-protection, pre-emptive multitaskingand symmetric multiprocessing support. Graphics are provided by agraphics engine known as Quartz. It has advanced-PDF standards support,OpenGL and Quicktime integrated into the OS. The operating systemfeatures are accessed through a graphical user interface called Aqua.Mac OS XLinuxtypeUnix-basedUnix-basedcomputerApple Macwide varietyfeaturesmemory-protection,pre-emptive multitasking, symmetricmultiprocessingsupportvariety ofdistribution kitsavailablegraphics engineQuartzXFree86standard supportadvanced-PDF,OpenGL, Quicktimeuser interface typeGUIcommand line, GUIuser interfaceAquaKDE, Gnomesource codeavailabilitynot availablefreely available4142UNIT 6 Operating SystemsSPECIALIST READINGBFind the answers to these questions in thefollowing text.1What did Linus Torvalds use to write theLinux kernel?How was the Linux kernel first madeavailable to the general public?What is a programmer likely to do withsource code?Why will most software companies not sellyou their source code?What type of utilities and applications areprovided in a Linux distribution?What is X ?What graphical user interfaces arementioned in the text?234567Linux has its roots in a student project.
In1992, an undergraduate called Linus Torvaldswas studying computer science in Helsinki,Finland. Like most computer science courses, abig component of it was taught on (and about)Unix. Unix was the wonder operating system ofthe 1970s and 1980s: both a textbook exampleof the principles of operating system design,and sufficiently robust to be the standard OS inengineering and scientific computing. But Unixwas a commercial product (licensed by ATEtT toa number of resellers), and cost more than astudent could pay.Annoyed by the shortcomings of Minix (acompact Unix clone written as a teaching aid byProfessor Andy Tannenbaum) Linus set out towrite his own 'kernel' — the core of anoperating system that handles memoryallocation, talks to hardware devices, and makessure everything keeps running. He used theGNU programming tools developed by RichardStallman's Free Software Foundation, anorganisation of volunteers dedicated to fulfillingStallman's ideal of making good software thatanyone could use without paying.
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