Computer Science Chapter 5

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is a bit in the context of data storage?

A graphical representation of data

A type of storage device for large amounts of data

A small memory unit used to store characters

A binary digit that can be either 0 or 1 (correct)

Which of the following represents a Boolean operation?

Storing data in a database

Combining multiple true/false values (correct)

Sorting a list of values

Adding two numbers together

What is the primary function of a gate in electronic circuits?

To transmit data over networks

To compress data for efficient storage

To compute Boolean operations (correct)

To store multiple bits in a memory bank

What does a flip-flop circuit primarily do?

Store a single bit of information Signup and view all the answers

Which of the following best describes the binary system?

A system that uses only two symbols to represent data Signup and view all the answers

What is a characteristic of mass storage compared to main memory?

Typically slower Signup and view all the answers

Which of the following is NOT a type of mass storage system mentioned?

Solid-state drives Signup and view all the answers

How is data organized on a magnetic disk storage system?

In concentric rings known as sectors Signup and view all the answers

What impacts the access time of a magnetic disk storage system?

The time for the read/write head to move and the sector to spin Signup and view all the answers

Which of the following statements is true about mass storage?

Usually less volatile than main memory Signup and view all the answers

What is the primary limitation of computer representations of numeric values?

Overflow and truncation errors Signup and view all the answers

Which bit pattern representation is primarily used for most symbols in written English text?

ASCII Signup and view all the answers

What technology is used primarily to record actual audio in sound representation?

Sampling techniques Signup and view all the answers

Which of the following best describes the binary system in relation to the decimal system?

Based on powers of two Signup and view all the answers

What does the term 'pixel' refer to in image representation?

A picture element Signup and view all the answers

What is the most popular means of representing integer values in computing?

Two's complement notation Signup and view all the answers

Which method is NOT used for representing sound in digital form?

Bitmap techniques Signup and view all the answers

Which of the following is NOT a format used by Unicode?

ASCII Signup and view all the answers

What happens when both input lines to a flip-flop are set to 0?

The flip-flop stores the most recently set value. Signup and view all the answers

How does hexadecimal notation simplify the representation of binary numbers?

By representing groups of four bits with a single symbol. Signup and view all the answers

What is the primary characteristic of Random Access Memory (RAM)?

Individual cells can be accessed in any order. Signup and view all the answers

What does the term 'most significant bit' refer to in a memory cell?

The bit that represents the highest value in the cell. Signup and view all the answers

What is the byte equivalent of 3 Kilobytes (KB)?

3072 bytes Signup and view all the answers

Which of the following correctly defines Dynamic Random Access Memory (DRAM)?

RAM composed of volatile memory. Signup and view all the answers

What identifies a memory cell in a computer's main memory?

Address, which is a unique number assigned to each cell. Signup and view all the answers

Which of the following is true for memory capacity measurements?

1 Terabyte equals $2^{40}$ bytes. Signup and view all the answers

What does a sign bit of S = 0 represent in the IEEE-754 floating-point representation?

A positive number Signup and view all the answers

What is the maximum value of a single-precision floating-point number?

3.40282 x 10^38 Signup and view all the answers

In the IEEE-754 format for double-precision, what is the bias used for the exponent?

1023 Signup and view all the answers

Which data compression technique is best suited for photographs?

JPEG Signup and view all the answers

Which encoding method is a type of lossy compression?

MP3 encoding Signup and view all the answers

What is the purpose of a parity bit in communication errors?

To check for errors in transmitted data Signup and view all the answers

Which of the following accurately describes Hamming distance?

The number of differing bits between two patterns Signup and view all the answers

What type of encoding method is Lossless Compression?

Run-length encoding Signup and view all the answers

What does seek time refer to in a magnetic disk storage system?

Time needed to position the read/write head over the correct track Signup and view all the answers

What is the average seek time given the arm movement time of 0.02 msec and an average of 300 tracks to move?

6 msec Signup and view all the answers

In a magnetic disk storage system, what is latency?

Time for the beginning of the desired sector to rotate under the read/write head Signup and view all the answers

What is the worst-case latency when the rotation speed is 7,200 rev/min?

8.33 msec Signup and view all the answers

How much time does it take for a sector to transfer, given that there are 64 sectors on a track?

4.17 msec Signup and view all the answers

If the read/write head must move on average 300 tracks, what is the worst-case seek time?

19.98 msec Signup and view all the answers

What is the rotation speed of the magnetic disk in rev/sec?

120 rev/sec Signup and view all the answers

What is the total number of bytes that can be stored on one track if there are 64 sectors each containing 1,024 bytes?

64,000 bytes Signup and view all the answers

Study Notes

Data Storage

Lecture slides adapted from the textbook "Computer Science: An Overview" by J. Glenn Brookshear and Dennis Brylow, published by Pearson.
Data storage topics include: bits and their storage, main memory, representing information as bit patterns, the binary system, storing integers, storing fractions, data compression, communication errors, and mass storage.

Bits and Bit Patterns

Bit: A binary digit (0 or 1).
Bit patterns represent information, including numbers, text characters, images, sound, and other data types.

Boolean Operations

Boolean operation: An operation that manipulates one or more true/false values.
Specific Boolean operations include AND, OR, XOR (exclusive or), and NOT.
Truth tables show the outputs for each operation based on different input combinations of 0s and 1s.

Gates

Gate: A device that computes a Boolean operation.
Gates are implemented as small electronic circuits.
Gates are the building blocks of computers.
VLSI (Very Large Scale Integration) is used in constructing modern computers.

Flip-Flops

Flip-flop: A circuit built from gates that can store one bit.
One input line sets the stored value to 1.
One input line sets the stored value to 0.
The most recently stored value is preserved when both input lines are 0.

Hexadecimal Notation

Hexadecimal notation: A shorthand notation for long bit patterns.
Groups bit patterns into groups of four bits each.
Represents each group with a single symbol.
Example: 10100011 becomes A3.

Main Memory

Cell: A unit of main memory, typically 8 bits (one byte).
Most significant bit: The leftmost bit in a memory cell.
Least significant bit: The rightmost bit in a memory cell.
Address: A unique identifier for each memory cell.
Addresses are numbered consecutively starting at zero.
Memory cells are organized by address in order.
Random Access Memory (RAM): Memory where individual cells can be accessed in any order.
Dynamic Memory (DRAM): A type of RAM that uses volatile memory.

Measuring Memory Capacity

Kilobyte (KB): 2^10 bytes (1024 bytes).
Megabyte (MB): 2^20 bytes (1,048,576 bytes).
Gigabyte (GB): 2^30 bytes (1,073,741,824 bytes).
Other units include terabyte (TB), petabyte (PB), and exabyte (EB).

Representing Information as Bit Patterns

Each character is assigned a unique bit pattern.
ASCII: Uses 7-bit patterns for English text.
ISO extensions use 8 bits to accommodate more languages.
Unicode uses 16-bit patterns for a wider range of symbols from various languages.

Representing Numeric Values

Binary notation: Uses bits to represent numbers in base two.
Limitations include overflow (value too big) and truncation (inaccurate representation).

Representing Images

Bit-map techniques represent images as pixels (picture elements) and use RGB color models or luminance and chrominance.
Vector techniques are scalable and use formats like TrueType and PostScript.

Representing Sound

Techniques like sampling record actual audio waves while MIDI uses musical score representation.

The Binary System

Decimal system is based on powers of ten.
Binary system is based on powers of two.
Binary representation of integers can be found through a method using division by 2 and recording remainders.
Integer arithmetic and addition can be conducted in the binary system.

Data Compression

Categorized as lossy or lossless methods.
Techniques include run-length encoding, Huffman codes, relative encoding, and dictionary encoding (like LZW).
Compression is used in images (GIF, JPEG, TIFF).

Communication Errors

Parity bits help detect errors (even or odd number of 1s).
Checkbytes verify data integrity.
Error-correcting codes identify and fix errors.
Hamming distance measures the differences in bit patterns between codes.

Mass Storage

Larger capacity compared to main memory.
Less volatile than main memory but typically slower.
Types of mass storage include magnetic disks (hard disks), magnetic tapes, optical disks (CDs, DVDs), and flash memory (memory cards, USB flash drives).

Magnetic Disks

Data is stored on spinning disks divided into sectors.
Access time depends on the seek time (positioning head), latency (time for sector to spin), and transfer time (data transfer rate).

Magnetic Tapes

Sequential access method; tapes move over the head.
Slower access time compared to disks.

CDs

Data is stored spirally on a single track.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on the fundamentals of data storage and electronic circuits in this quiz. Questions cover Boolean operations, flip-flop circuits, and mass storage characteristics. Perfect for students studying computer science concepts.