习题+答案2.1Write T or F to each stateme ntT6. An asynchronous device is a clocked device.T7. A latch is an asynchronous device, because it functions at arbitrary times.T8. The repetiti on of clock pulse can vary from very low rate to very high rate.T9. A synchronous device changes its state only on the arrival of a clock pulse.F10. A clock in put may occur at any time.T11. The clock pulses are used to synchronize all operations of the shift register.T13. A uni direct ional shift register is capable of shift ing in one direct ion only.F14. I n a shift-left register the serial in put determ ines what goes into the leftmost position during the shift register.F15. To provide parallel tran sfer capability some additi onal in put and output lines should be provided to the shift register.Choose the best an swer for each of the follow ing1. How can the output of a logic gate be en ergized? CA By cha nging its in puts.B By rema ining its in puts un cha nged.C By meet ing the specific in put con diti on.D By givi ng a pulse.3. A NAND gate con sists of D .A an OR gate followed by an in verterB an AND gate followed by an in verterC an AND gate followed by an OR gateD an in verter followed by an AND gate4. Un der what con diti on is the output of a two-i nput XOR gate logic-high? BA Its in puts are simulta neously at the same logic level.B Its in puts are simulta neously at opposite logic levels.C Its in puts are logic-low.D its in puts are simulta neously logic-high.2.2Write T or F for each stateme ntT 1. The CPU uses the in put and output un its to com muni cate with the outside world.F2. Main memory is sometimes called exter nal memory.F3. After execution the program and the related files of data and files of information will be retained in the main memory for later use.F4. Personal computers have not the features of the larger system..T5. Large systems offer higher process ing speeds for user and retur n more data tha n PCs.F6. CPUs all size have primary storage, arithmetic logic, and the con trol sect ion.F7. The output device is the heart of any computer system.T8. The in put/output devices and auxiliary storage un its of a computer system are called peripherals.F9. The in strume nt of in terpretati on and com muni cati on betwee n huma ns and computers system of all sizes is CPU.an F10 Special purpose computers can adapted to many situation by giving them appropriate program.F11 .A mi nicomputer is the smallest and least expe nsive type of computer.T12. A special purpose computer performs only one specific task and thus lacks versatility.T13. The larger the system the greater is its process ing speed, storage capacity.T14. Mai nframe computers are desig ned to process complex scie ntific applicati on.T 9. The main memory in a gen eral-purpose computer is made up of RAM in tegratedcircuit chip.\F 10. When the power is turned on, the program coun ter is set the first address of the bootstrap loaderby the software of the computer.T 11. The read-write heads con tact the surface of the floppy disks.T 12. The data on a particular track will be switched automatically onto a spare trackby the computer before a catastrophic failure would occur.F 14. The read write heads stay on the same track continuously when the disk drive isWorki ngF 16. The possible symbols in the binary nu mberi ng system are q to 9.F 17. The decimal value of 16 is represented in 4 bits BCD as 00010101.F 18. Alpha nu meric versions of BCD com monly use 6,7or 8 bits to represe nt characters.F 19. A 6 bit alpha nu meric code can represe nt 128 differe nt characters.F 22. Eight bit codes are limited to represe nting 128 differe nt characters.T23. An extra check (or parity ) bit is often added to each 6, 7, or 8 bit character represented in storage so that it will be possible to detect codi ng errors that may occur.T 24. If a computer uses an odd parity format to detect errors in character codes, the n every valid character code will always have an odd number of 1 bits.T 25. Processor comes with a unique set of operati ons called an in struct ion set.F 26. In an in struct ion, opera nds specify the fun cti on to be performed.T 27. A processor's job is to retrieve in structio n from memory and perform step bystep operati ons,3.3 True or FalseF1 All operati ng systems on various computers take the same size.F 2 All operati ng systems were writte n in a low level Ian guage.T3 The user can't use the computers at all if there is no operating system on the computers.F4 The operati ng system exists in the lowest layer of a computer.T5 The system calls are provided by the operati ng system.T 6 A computer's operati onal software defi nes the schedule of jobs await ing executi on.F7 Though an operati ng system can schedule the executi on of jobs, it does not man age the availability of I/O devices.T 8 The IOCS comp onent of an operat ing system con trols I/O operati ons.T9 It is a major problem for the operati ng system to map the logical file con cept onto physicalstorage devices such as magn etic tape or disk.F10 Files can only be direct access on a disk system.T 11 The logic structure and nomen clature of the differe nt operati ng systems vary considerable.F12 The form of the system prompt is the same for every kind of operating system 13 You must boot the system, before you use a microcomputer.T14 Spooling is an approach to improving system performance by over aping thein put of one job with the output of other jobs.T15 Multiprogramming allows time sharing.T1 6 When they first appeared, the microcomputers were provided with the operati ng systemdeveloped for computers.T17 By using the graphical user in terface, what the users n eed to do is to "po int and click" inorder to accomplish their tasks.T18 The in terface in troduced by Win dows is the object-orie nted user in terface.T 19.TMicrosoft failed in bett ing their future on Win dows.Multiple Choice1 A computer's operati ng system is: Da resource man ageme nt 2 Which is the gen eralizati on of a two-level directory? Da cycle graph directory structure c batchsystem3 Which system may have no time con stra ins? Ca real-time systemc batch system4 The more popular micro operati ng system isa MS-DOS d all the above 5 What la nguages can be used to develop the operat ing systems ?C a A machi ne Ian guage,b An assembly Ian guage.c A high level la nguage,d all of the above. 6 How does the operati ng system man age the resources of the computer?a It turns on or off the resources of the computer.b It makes them work together towards some com mon goals, or objectives.c It con trols the way in which these resources are put to work.d It acts directly on the raw hardware.7 The function of an operati ng system is Da to drive the the raw hardware of the computerb to drive the resources of the computer in accorda nce with certa in objectivesc to provide the higher layers of software with a simplified computerb error recoveryc memory man ageme ntd all the aboveb a tree-structured d all the above b time-share system d all the above :D b CP/Mc UNIXd all of the above11 The graphical user in terface provides the users withA a simpler way to in teract with their computersB a series of typed comma ndsC an in tuitive sit of graphical icons that allowed the completi on of com mon tasksD an intuitive set of graphical incons for users to "point and click" in accomplish theirtasks, so that they did n't have to remember arcane words and comma nds anymore12 Win dows resemble the Macin tosh inA providi ng a GUI which is in troduced by Macin toshB providi ng a limited means of multitask ingC providi ng a Win dows in terface just like the GUID allowing users to load multiple programs and have them run in thebackgro und while doing other work in a window in the foregro und3.4 True or FalseF1 Flowchart ing is used primarily for program desig n and rarely for systems desig n.T2 When programming in a procedure-orientedIanguage, you should computer''what to do' and 'how to do it'.T3 Assembler-level Ian guages use mnemonics to represe nt in struct ions.T4 Mach ine Ian guage in struct ions are composed of a label, an opcode, and an opera nd.F5 Mach ine Ian guages must be con verted by a compiler to be used by the computer.F6 High-level la nguages require that programmers work with in dividual main storage location s.. 5T7 A compiler is tran slat ing program that con verts high-level Ian guages intomach ine Ian guage.T9 A flowchart loop in dicates the repetitive performa nee of steeps to process data.T10 None of the computers con sists of hardware on ly.F11 Programs written in high-level la nguage can be executed by the computers without thehelp of a tran slator program~T13 Each symbolic in struct ion has on e-to-one corresp ondence with the mach ine instructio n.T 14 Writing a program in a high-level Ianguage need not take account hardwareof the computer.T 15 The opode of an assembly Ian guage in struct ion specifies the operatio n that is to beperformed by the microprocessor.T 17 The mnemonic for the instruction is the symbolic representation of the actual binarycode that the computer directly executes.T 18 A label is on the left of the assembly Ian guage stateme nt.T 21 To en able the computer to solve an applicati on problem programmers have to writeprograms in order to tran slate the applicati on con cepts into computer con cepts.T 22 A class is defi ned by group ing a user-defi ned type with all procedures and function that canbe applied to it.order to tell the of theT 23 The artificial in tellige nee research com munity did not agree with the con cepts of object-orie nted program ming whe n in its early days.F24 Object-orie nted program ming Ian guages are absolutely differe nt from the LISP program ming Ian guage.T 25 A program may produce in correct output even if it runs OK.T 26 An error will occur if a program wants to use a deleted file.F 27 All the errors can be avoided.T 28 A warni ng will not termi nate the program.T 29 Although we could not avoid all the run time errors, we must take appropriate action whe n it happe ns.Match the followi ng terms to the appropriate defi niti on1 program2 programmer3 mach ine Ian guage4 assembler5 source6 object7 in terpreter8 compilerA A computer program that tran slates an in structio n into mach ine Ian guage, executeit, and the n repeats the process for each in struct ion in a program un til the program is finished. 7B The set of stateme nts that make up a computer program .5C A computer program that reads a high-level la nguage in structio n. 8D A computer-specific set of primitive or eleme ntary in structi ons that allows peopleto com muni cate with a particular computer. 3E A set of in struct ion that tells a computer what to do. 1F A program that tran slates an assembly-level Ian guage into mach ine Ian guage 4.G Output from a compiler or assembler that is lin ked with other code to produce executable mach ine Ian guage code. 6H A pers on who creates computer program. 23.5True or falseT1 The program specificati ons are writte n by the software engin eers.F2 Codi ng a program will con sume most of programmer's time and effort.T 3 Programmers should use flowchart and other visual aids whe n they are desig ning routi nes. F4 The goal of the test phase of program developme nt is to "prove" that a particular program has bee n completely debugged.T 5 More programmers maintain programs rather tha n code programs.T 6 A structured program is made up of several modules.T 7 "Branching" capability is one the most intriguing properties of a digital computer.。