Database Assignment

Chapter 1: 1, 2, 6, 7, 8, 11.

1. EXPLAIN each OF the following terms IN your own words:
    a) Translator.
    b) Interpreter.
    c) Virtual machine.

2. What IS the difference BETWEEN interpretation AND translation?

6. SOME instructions at the operating system machine level are identifical TO ISA LANGUAGE instructions. These instructions are carried OUT directly BY the microprogram rather than BY the operating system. IN light OF your answer TO the preceding problem, why do you think this IS the CASE?

7. Consider a computer WITH identifical interpreters at levels 1, 2, AND 3. It takes an interpreter n instructions TO fetch, examine, AND EXECUTE one instruction. A level 1 instruction takes k nanoseconds TO EXECUTE. How long does it take FOR an instruction at levels 2, 3, AND 4?

8. IN what sense are hardware AND software equivalent? NOT equivalent?

11. The performance ratio OF the 360 model 75 was 50 times that OF the 360 model 30, yet the cycle TIME was ONLY five times AS fast/ How do you account FOR this discrepancy?

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                Chapter 2
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Chapter 2: 1, 3, 9, 11, 12, 15, 16, 17, 19, 25.

1. Consider the operation OF a machine WITH the DATA path OF Figure 2-2. Suppose that loading the ALU INPUT registers takes 5 nsec, running the ALU takes 10 nsec, AND storing the RESULT back IN the register scratchpad takes 5 nsec. What IS the maximum NUMBER OF MIPS this machine IS capable OF IN the absence OF pipelining?

3. ON computer 1, ALL instructions take 10 nsec TO EXECUTE. ON computer 2, they ALL take 5 nsec TO EXECUTE. Can you say FOR certain that computer 2 IS faster? Discuss.

9. Compute the DATA rate OF the human eye USING the following information. The visual FIELD consists OF about 10^6 elements (pixels). Each pixel can be reduced TO a superposition OF the three PRIMARY colors, each OF which has 64 intensities. The TIME resolution IS 100 msec.

11. Genetic information IN ALL living things IS coded AS DNA molecules. A DNA molecule IS a linear SEQUENCE OF the four basic nucleotides: A, C, G, AND T. The human genome contains approximately 3 x 10^9 nucleotides INT he form OF about 30,000 genes. What IS the total information capacity (IN bits) OF the human genome? What IS the maximum information capacity (IN bits) OF the average gene?

12. A certain computer can be equipped WITH 268, 435, 456 bytes OF memory. Why would a manufacturer choose such a peculiar NUMBER, instead OF an easy-to-remember NUMBER LIKE 250,000,000?

15. IN a Hamming code, SOME bits are "wasted" IN the sense that they are used FOR checking AND NOT information. What IS the percentage OF wasted bits FOR messages whose total LENGTH (DATA + CHECK bits) IS 2^n - 1? Evaluate this expression numerically FOR VALUES OF n FROM 3 TO 10.

16. The disk illustrated IN Figure 2-19 has 1024 sectors/track AND a rotation rate OF 7200RPM. What IS the sustained transfer rate OF the disk OVER one track?

17. A computer has a bus WITH 5 nsec cycle TIME, during which it can READ OR WRITE a 32-bit word FROM memory. The computer has an Ultra4-SCSI disk that uses the bus AND AND runs at 160 Mbytes/sec. The CPU normally fetches AND executes one 32-bit instruction every 1 nsec. How much does the disk slow down the CPU?

19. How long does it take TO READ a disk WITH 10,000 cylinders, each containing four tracks OF 2048 sectors? FIRST, ALL the sectors OF track 0 are TO be READ starting at sector 0, THEN ALL the sectors OF track 1 starting at sector 0, AND so ON. The rotation TIME IS 10 msec, AND a seek takes 1 msec BETWEEN adjacent cylinders AND 20 msec FOR the worst CASE. Switching BETWEEN tracks OF a cylinder can be done instantaneously.

25. The transfer rate BETWEEN a CPU AND its associated memory IS orders OF magnitude higher than the mechanical I/O  transfer rate. How can this imbalance cause inefficiencies? How can it be alleviated?