New Semester
Started
Get
50% OFF
Study Help!
--h --m --s
Claim Now
Question Answers
Textbooks
Find textbooks, questions and answers
Oops, something went wrong!
Change your search query and then try again
S
Books
FREE
Study Help
Expert Questions
Accounting
General Management
Mathematics
Finance
Organizational Behaviour
Law
Physics
Operating System
Management Leadership
Sociology
Programming
Marketing
Database
Computer Network
Economics
Textbooks Solutions
Accounting
Managerial Accounting
Management Leadership
Cost Accounting
Statistics
Business Law
Corporate Finance
Finance
Economics
Auditing
Tutors
Online Tutors
Find a Tutor
Hire a Tutor
Become a Tutor
AI Tutor
AI Study Planner
NEW
Sell Books
Search
Search
Sign In
Register
study help
computer sciences
systems analysis and design
Computer organization and architecture designing for performance 8th edition William stallings - Solutions
Explain the term striped data.
In the context of RAID, what is the distinction between parallel access and independent access?
What is the difference between CAV and CLV?
What differences between a CD and a DVD account for the larger capacity of the latter?
Explain serpentine recording.
How are data written onto a magnetic disk?
How are data read from a magnetic disk?
Explain the difference between a simple CAV system and a multiple zoned recording system.
Define the terms track, cylinder, and sector.
Define the terms seek time, rotational delay, access time, and transfer time.
What common characteristics are shared by all RAID levels?
Briefly define the seven RAID levels. Discuss.
Consider a disk with N tracks numbered from 0 to (N - 1) and assume that requested sectors are distributed randomly and evenly over the disk. We want to calculate the average number of tracks traversed by a seek.a. First, calculate the probability of a seek of length j when the head is currently
Design a backup strategy for a computer system. One option is to use plug-in external disks, which cost $150 for each 500 GB drive. Another option is to buy a tape drive for $2500, and 400 GB tapes for $50 apiece. (These were realistic prices in 2008.) A typical backup strategy is to have two sets
Consider a magnetic disk drive with 8 surfaces, 512 tracks per surface, and 64 sectors per track. Sector size is 1 KB. The average seek time is 8 ms, the track-to-track access time is 1.5 ms, and the drive rotates at 3600 rpm. Successive tracks in a cylinder can be read without head movement. a.
Consider a single-platter disk with the following parameters: rotation speed: 7200 rpm; number of tracks on one side of platter: 30,000; number of sectors per track: 600; seek time: one ms for every hundred tracks traversed. Let the disk receive a request to access a random sector on a random track
A distinction is made between physical records and logical records. A logical record is a collection of related data elements treated as a conceptual unit, independent of how or where the information is stored. A physical record is a contiguous area of storage space that is defined by the
Consider a disk that rotates at 3600 rpm. The seek time to move the head between adjacent tracks is 2 ms. There are 32 sectors per track, which are stored in linear order from sector 0 through sector 31.The head sees the sectors in ascending order. Assume the read/write head is positioned at the
It should be clear that disk striping can improve data transfer rate when the strip size is small compared to the I/O request size. It should also be clear that RAID 0 provides improved performance relative to a single large disk, because multiple I/O requests can be handled in parallel. However,
Consider a 4-drive, 200GB-per-drive RAID array. What is the available data storage capacity for each of the RAID levels, 0, 1, 3, 4, 5, and 6?
For a compact disk, audio is converted to digital with 16-bit samples, and is treated a stream of 8-bit bytes for storage. One simple scheme for storing this data, called direct recording, would be to represent a 1 by a land and a 0 by a pit. Instead, each byte is expanded into a 14-bit binary
List three broad classifications of external, or peripheral, devices.
What is the International Reference Alphabet?
List and briefly define three techniques for performing I/O. Discuss.
What is the difference between memory-mapped I/O and isolated I/O?
On a typical microprocessor, a distinct I/O address is used to refer to the I/O data registers and a distinct address for the control and status registers in an I/O controller for a given device. Such registers are referred to as ports. In the Intel 8088, two I/O instruction formats are used. In
Consider a system employing interrupt-driven I/O for a particular device that transfers data at an average of 8 KB/s on a continuous basis. a. Assume that interrupt processing takes about 100 μs (i.e., the time to jump to the interrupt service routine (ISR), execute it, and return to the main
In virtually all systems that include DMA modules, DMA access to main memory is given higher priority than CPU access to main memory. Why?
A DMA module is transferring characters to memory using cycle stealing, from a device transmitting at 9600 bps. The processor is fetching instructions at the rate of 1 million instructions per second (1 MIPS). By how much will the processor be slowed down due to the DMA activity?
Consider a system in which bus cycles takes 500 ns. Transfer of bus control in either direction, from processor to I/O device or vice versa, takes 250 ns. One of the I/O devices has a data transfer rate of 50 KB/s and employs DMA. Data are transferred one byte at a time. a. Suppose we employ DMA in
Examination of the timing diagram of the 8237A indicates that once a block transfer begins, it takes three bus clock cycles per DMA cycle. During the DMA cycle, the 8237A transfers one byte of information between memory and I/O device. a. Suppose we clock the 8237A at a rate of 5 MHz. How long does
Assume that in the system of the preceding problem, a memory cycle takes 750 ns. To what value could we reduce the clocking rate of the bus without effect on the attainable data transfer rate?
A DMA controller serves four receive-only telecommunication links (one per DMA channel) having a speed of 64 Kbps each. a. Would you operate the controller in burst mode or in cycle-stealing mode? b. What priority scheme would you employ for service of the DMA channels?
A 32-bit computer has two selector channels and one multiplexor channel. Each selector channel supports two magnetic disk and two magnetic tape units. The multiplexor channel has two line printers, two card readers, and 10 VDT terminals connected to it. Assume the following transfer rates: Disk
A computer consists of a processor and an I/O device D connected to main memory M via a shared bus with a data bus width of one word. The processor can execute a maximum of 106 instructions per second. An average instruction requires five machine cycles, three of which use the memory bus. A memory
A data source produces 7-bit IRA characters, to each of which is appended a parity bit. Derive an expression for the maximum effective data rate (rate of IRA data bits) over an R-bps line for the following: a. Asynchronous transmission, with a 1.5-unit stop bit b. Bit-synchronous transmission, with
A similar instruction format is used in the Zilog Z8000 microprocessor family. In this case, there is a direct port addressing capability, in which a 16-bit port address is part of the instruction, and an indirect port addressing capability, in which the instruction references one of the 16-bit
The following problem is based on a suggested illustration of I/O mechanisms in [ECKE90] (Figure 7.22): Two women are on either side of a high fence. One of the women, named Apple-server, has a beautiful apple tree loaded with delicious apples growing on her side of the fence; she is happy to
Assume that one 16-bit and two 8-bit microprocessors are to be interfaced to a system bus. The following details are given: 1. All microprocessors have the hardware features necessary for any type of data transfer: programmed I/O, interrupt-driven I/O, and DMA. 2. All microprocessors have a 16-bit
Consider a microprocessor that has a block I/O transfer instruction such as that found on the Z8000. Following its first execution, such an instruction takes five clock cycles to re-execute. However, if we employ a non blocking I/O instruction, it takes a total of 20 clock cycles for fetching and
A system is based on an 8-bit microprocessor and has two I/O devices. The I/O controllers for this system use separate control and status registers. Both devices handle data on a 1-byte-at-a-time basis. The first device has two status lines and three control lines. The second device has three
For programmed I/O, Figure 7.5 indicates that the processor is stuck in a wait loop doing status checking of an I/O device. To increase efficiency, the I/O software could be written so that the processor periodically checks the status of the device. If the device is not ready, the processor can
A microprocessor scans the status of an output I/O device every 20 ms. This is accomplished by means of a timer alerting the processor every 20 ms. The interface of the device includes two ports: one for status and one for data output. How long does it take to scan and service the device given a
In Section 7.3, one advantage and one disadvantage of memory-mapped I/O, compared with isolated I/O, were listed. List two more advantages and two more disadvantages.
A particular system is controlled by an operator through commands entered from a keyboard. The average number of commands entered in an 8-hour interval is 60. a. Suppose the processor scans the keyboard every 100 ms. How many times will the keyboard be checked in an 8-hour period? b. By what
What is the purpose of a translation look aside buffer?
List and briefly define the key services provided by an OS.
List and briefly define the major types of OS scheduling.
Suppose that we have a multi programmed computer in which each job has identical characteristics. In one computation period, T, for a job, half the time is spent in I/O and the other half in processor activity. Each job runs for a total of N periods. Assume that a simple round-robin priority is
In the VAX computer, user page tables are located at virtual addresses in the system space. What is the advantage of having user page tables in virtual rather than main memory? What is the disadvantage?
Suppose the program statement for (i = 1; i
The IBM System/370 architecture uses a two-level memory structure and refers to the two levels as segments and pages, although the segmentation approach lacks many of the features described earlier in this chapter. For the basic 370 architecture, the page size may be either 2 Kbytes or 4 Kbytes,
Consider a computer system with both segmentation and paging. When a segment is in memory, some words are wasted on the last page. In addition, for a segment size s and a page size p, there are s/p page table entries. The smaller the page size, the less waste in the last page of the segment, but
A computer has a cache, main memory, and a disk used for virtual memory. If a referenced word is in the cache, 20 ns are required to access it. If it is in main memory but not in the cache, 60 ns are needed to load it into the cache, and then the reference is started again. If the word is not in
Assume a task is divided into four equal-sized segments and that the system builds an eight-entry page descriptor table for each segment. Thus, the system has a combination of segmentation and paging. Assume also that the page size is 2 KBytes. a. What is the maximum size of each segment? b. What
Assume a microprocessor capable of accessing up to 232 bytes of physical main memory. It implements one segmented logical address space of maximum size 231 bytes. Each instruction contains the whole two-part address. External memory management units (MMUs) are used, whose management scheme assigns
Consider a paged logical address space (composed of 32 pages of 2 KBytes each) mapped into a 1-MByte physical memory space. a. What is the format of the processor's logical address? b. What is the length and width of the page table (disregarding the "access rights" bits)? c. What is the effect on
In IBM's mainframe operating system, OS/390, one of the major modules in the kernel is the System Resource Manager (SRM). This module is responsible for the allocation of resources among address spaces (processes). The SRM gives OS/390 a degree of sophistication unique among operating systems. No
For each of the ARM virtual address formats shown in Figure 8.24, show the physical address format.
An I/O-bound program is one that, if run alone, would spend more time waiting for I/O than using the processor. A processor-bound program is the opposite. Suppose a short-term scheduling algorithm favors those programs that have used little processor time in the recent past. Explain why this
Draw a figure similar to Figure 8.23 for ARM virtual memory translation when main memory is divided into sections.
A program computes the row sumsof an array A that is 100 by 100. Assume that the computer uses demand paging with a page size of 1000 words, and that the amount of main memory allotted for data is five page frames. Is there any difference in the page fault rate if A were stored in virtual memory by
Consider a fixed partitioning scheme with equal-size partitions of 216 bytes and a total main memory size of 224 bytes. A process table is maintained that includes a pointer to a partition for each resident process. How many bits are required for the pointer?
Consider a dynamic partitioning scheme. Show that, on average, the memory contains half as many holes as segments. Discuss.
Suppose the page table for the process currently executing on the processor looks like the following. All numbers are decimal, everything is numbered starting from zero, and all addresses are memory byte addresses. The page size is 1024 bytes.a. Describe exactly how, in general, a virtual address
Give reasons that the page size in a virtual memory system should be neither very small nor very large.
A process references five pages, A, B, C, D, and E, in the following order: A; B; C; D; A; B; E; A; B; C; D; E Assume that the replacement algorithm is first-in-first-out and find the number of page transfers during this sequence of references starting with an empty main memory with three page
The following sequence of virtual page numbers is encountered in the course of execution on a computer with virtual memory: 3 4 2 6 4 7 1 3 2 6 3 5 1 2 3 Assume that a least recently used page replacement policy is adopted. Plot a graph of page hit ratio (fraction of page references in which the
Briefly explain the following representations: sign magnitude, twos complement, biased.
What are the differences among positive overflow, exponent overflow, and significand overflow?
What are the basic elements of floating-point addition and subtraction?
List four alternative methods of rounding the result of a floating-point operation.
What is the difference between the twos complement representation of a number and the twos complement of a number?
If we treat 2 twos complement numbers as unsigned integers for purposes of addition, the result is correct if interpreted as a twos complement number. This is not true for multiplication. Why?
Represent the following decimal numbers in both binary sign/magnitude and twos complement using 16 bits: +512; -29.
Assume numbers are represented in 8-bit twos complement representation. Show the calculation of the following: a. 6 + 13 b. -6 + 13 c. 6 - 13 d. -6 - 13
Find the following differences using twos complement arithmetic: a. 111000 -110011 b. 11001100 - 101110 c. 111100001111 -110011110011 d. 11000011 -11101000
Is the following a valid alternative definition of overflow in twos complement arithmetic? If the exclusive-OR of the carry bits into and out of the leftmost column is 1, then there is an overflow condition. Otherwise, there is not.
Given x = 0101 and y = 1010 in twos complement notation (i.e., x = 5, y = -6), compute the product p = x × y with Booth's algorithm.
Use the Booth algorithm to multiply 23 (multiplicand) by 29 (multiplier), where each number is represented using 6 bits.
Prove that the multiplication of two n-digit numbers in base B gives a product of no more than 2n digits.
The twos complement integer division algorithm described in Section 9.3 is known as the restoring method because the value in the A register must be restored following unsuccessful subtraction. A slightly more complex approach, known as non restoring, avoids the unnecessary subtraction and
Represent the following twos complement values in decimal: 1101011; 0101101.
Divide -145 by 13 in binary twos complement notation, using 12-bit words. Use the algorithm described in Section 9.3.
a. Consider a fixed-point representation using decimal digits, in which the implied radix point can be in any position (e.g., to the right of the least significant digit, to the right of the most significant digit, and so on). How many decimal digits are needed to represent the approximations of
Express the following numbers in IEEE 32-bit floating-point format: a. -5 b. -6 c. -1.5 d. 384 e. 1/16 f. -1/32
The following numbers use the IEEE 32-bit floating-point format. What is the equivalent decimal value? a. 1 10000011 11000000000000000000000 b. 0 01111110 10100000000000000000000 c. 0 10000000 00000000000000000000000
Consider a reduced 7-bit IEEE floating-point format, with 3 bits for the exponent and 3 bits for the significand. List all 127 values.
Express the following numbers in IBM's 32-bit floating-point format, which uses a 7-bit exponent with an implied base of 16 and an exponent bias of 64 (40 hexadecimal).A normalized floating-point number requires that the leftmost hexadecimal digit be nonzero; the implied radix point is to the left
What would be the bias value for a. A base-2 exponent (B = 2) in a 6-bit field? b. A base-8 exponent (B = 8) in a 7-bit field?
Draw a number line similar to that in Figure 9.19b for the floating-point format of Figure 9.21b.
Another representation of binary integers that is sometimes encountered is ones complement. Positive integers are represented in the same way as sign magnitude. A negative integer is represented by taking the Boolean complement of each bit of the corresponding positive number. a. Provide a
Consider a floating-point format with 8 bits for the biased exponent and 23 bits for the significand. Show the bit pattern for the following numbers in this format: a. -720 b. 0.645
The text mentions that a 32-bit format can represent a maximum of 232 different numbers. How many different numbers can be represented in the IEEE 32-bit format? Explain.
Any floating-point representation used in a computer can represent only certain real numbers exactly; all others must be approximated. If A′ is the stored value approximating the real value A, then the relative error, r, is expressed as r = A - A′/A Represent the decimal quantity +0.4 in the
If A = 1.427, find the relative error if A is truncated to 1.42 and if it is rounded to 1.43.
When people speak about inaccuracy in floating-point arithmetic, they often ascribe errors to cancellation that occurs during the subtraction of nearly equal quantities. But when X and Y are approximately equal, the difference X - Y is obtained exactly, with no error. What do these people really
Numerical values A and B are stored in the computer as approximations A′ and B′. Neglecting any further truncation or round off errors, show that the relative error of the product is approximately the sum of the relative errors in the factors.
One of the most serious errors in computer calculations occurs when two nearly equal numbers are subtracted. Consider A = 0.22288 and B = 0.22211. The computer truncates all values to four decimal digits. Thus A′ = 0.2228 and B′ = 0.2221. a. What are the relative errors for A′ and B′? b.
Showing 2400 - 2500
of 3385
First
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
Last
Step by Step Answers