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What are the four components of an IT system that you will study in this book?
The four components are: hardware, software, data, and interconnectivity.
One way to view an information technology system is to consider an IT system as consisting of four major components or building blocks. This book takes this approach by dividing the remainder of the book into parts, with a part devoted to each major type of component. What are the four components of an IT system that you will study in this book?
The two major categories of software: system software and application software. system software helps you to manage your files, to load and execute programs, and to accept your commands. An example of this is the operating system.
Application software helps users complete specific tasks. An example of this would be Microsoft Office.
Virtualization is a concept that has taken on major importance in the early twenty‐first century. Explain what is meant by virtualization.
Virtualization allows one computer to acta like multiple computers, and each has their own operating system and hardware resources
Explain the differences between primary storage and secondary storage. What is each type used for?
Primary storage is known as RAM and is accessible through the CPU. It is used for actively accessible data. Each cell holds a single binary number representing part of a data value or part of an instruction.
Secondary storage is used for long-term storage.
The book compares a large mainframe computer to a smartphone or tablet, and states that the difference between them is one of magnitude, not of concept. Explain the meaning of that statement.
The book states that the difference between a large mainframe computer and a smartphone or tablet is one of scale, not of fundamental concept. The book compares a large mainframe computer to a smartphone or tablet, highlighting that the difference between them is primarily a matter of scale rather than a difference in fundamental concept. In other words, while the mainframe computer may be significantly larger and more powerful than a smartphone or tablet, they are still fundamentally similar in terms of their underlying principles and functionality.
What is a protocol? What is a standard? Do all protocols have to be standards? Explain. Are all standards protocols? Explain
A protocol is a set of rules for communication between devices or systems. It defines the format, timing, sequencing, and error control of data transmission. A standard, on the other hand, is a widely accepted specification or requirement that serves as a reference for consistency and interoperability. Not all protocols have to be standards. While protocols often adhere to established standards, there can be proprietary protocols that are specific to certain systems or companies. Standards, on the other hand, can encompass various aspects such as protocols, specifications, guidelines, and regulations. Therefore, not all standards are protocols. Protocols and standards are related but serve different purposes. Protocols define the rules for communication, while standards provide a framework for consistency and interoperability across systems or devices.
Explain the relationships among the following words: system, environment, boundary, and interface
a "system boundary" is the line that separates a system from its "environment," defining what is considered part of the system and what is external to it; while an "interface" is the point of interaction or connection between the system and its environment, essentially how the system exchanges information or interacts with external entities within its boundary
Explain what is meant by the architecture of a system.
The architecture of a system encompasses the fundamental properties and patterns of relationships, connections, constraints, and linkages among the components and between the system and its environment.
What are the principal responsibilities of a system architect?
A systems architect is responsible for designing and creating an optimal system based on the organization’s needs, budget, network capabilities, and user convenience. They study and analyze IT systems as a whole, including computer systems, network infrastructure, software, and web systems. A key responsibility is identifying the purpose of each component and defining the requirements for the interfaces and linkages that connect them, ensuring that all parts of the system work seamlessly together.
What are the most important ideas, keywords, and phrases that are stated in the definition of a system?
The most important characteristic from the definition of a system is that each system is built from a set of components that are linked together to form a single unit.
Explain the following statement about systems: “Decomposition is inherently hierarchical”.
The given statement means when you break down a complex system into smaller parts they naturally will form a level of importance.
What does the top‐down approach allow a system architect to do that might be more difficult otherwise?
The top down approach lets us focus on certain areas of importance without getting distracted by the details that aren’t important for what we are looking at. This helps to focus on the larger picture.
Name the three standards in common use for alphanumeric characters. Which standard is designed to support all of the world's written languages? Which language is used primarily with legacy programs that execute on mainframe computers?
Unicode: Developed for worldwide use
ASCII: Developed by ANSI
EBCDIC: Used primarily with legacy programs that execute on mainframe computers
What is a collating sequence?
ASCII and EBCDIC are designed so that a simple numerical code can be used to perform alphabetization the order of the codes is known as its collating sequence.
What is image metadata? Give an at least three examples of metadata that would be required for a bitmap image.
Metadata is data that describes or interprets the data. Some examples are the number of colors represented by each data point, the number of horizontal and vertical data points and the location of the image on the screen
What is the function of a video codec? What is the function of a video “container”? Name at least two different codecs. Name at least two different containers.
The video format is determined by a codec. Encoder or Decoder. MPEG-2 and MPEG-4 are two types of code. Containers holds as a superstructure to encode, decode hold and stream the video such as google webM and MP4
Describe briefly the most important characteristics and features of an MP3 audio file.
lossy compression techniques to minimize storage requirements and is known for its ability to preserve the highest frequencies that most people can hear.
What is a page description language? Give an example of a page description language.
A language that describes the layout of objects on a displayed or printed page. HTML is an example.
Explain the difference between numeric characters and numbers. Under what conditions would you expect the computer to use numeric characters? When would you expect the computer to use numbers? When numeric data is entered at the keyboard, which form is used? Which form is used for calculations? Which form is used for display?
Numeric characters are symbols that represent numerical values, such as "0", "1", "2", etc. Numbers, on the other hand, are the actual values themselves, such as 0, 1, 2, etc. The computer uses numeric characters when representing numerical values in a text-based form. This can be seen when numeric data is entered at the keyboard, where the user inputs numeric characters to represent numbers. When performing calculations or manipulations with numerical data, the computer uses the actual numbers rather than the numeric characters. This allows for mathematical operations to be performed accurately. For display purposes, the computer may use either numeric characters or numbers, depending on the context and requirements of the application or system. Numeric characters may be used when the numerical values need to be presented as text, while actual numbers may be used when the values need to be processed or formatted for specific purposes.
Instructions in the Little Man Computer are three digits, divided into two parts. Show the format of an LMC instruction.
Describe, step by step, what the Little Man does to execute an INPUT instruction.
To execute an INPUT instruction, the Little Man performs the following steps:
Fetches the INPUT instruction from the memory
Prompts the user to input a value.
Stores the inputted value in the accumulator.
If a user wants to enter two numbers, what must the Little Man program do before she enters the second number? Why?
Before the user enters the second number, the Little Man program must clear the accumulator to ensure it doesn't carry over the value from the first input. This is necessary to accurately process the second input.
Explain carefully, step by step, what the Little Man will do when he executes a BRANCH ON ZERO instruction.
When executing a BRANCH ON ZERO instruction, the Little Man performs the following steps:
Fetches the instruction from the memory.
Checks if the accumulator's value is zero.
If the accumulator's value is zero, it jumps to the specified address; otherwise, it proceeds to the next instruction in sequence.
Even if he runs out of instructions to execute, the Little Man only stops trying to execute instructions under one condition. What is that condition? What happens if the Little Man runs out of instructions and that condition is not met?
The Little Man only stops trying to execute instructions if it encounters a HALT instruction. If the Little Man runs out of instructions and doesn't encounter a HALT instruction, it will continue trying to execute instructions, leading to an infinite loop or undefined behavior.
What does the Little Man do during the second phase of a COFFEE BREAK or HALT instruction?
During the second phase of a COFFEE BREAK or HALT instruction, the Little Man stops executing instructions and enters a state of rest, waiting for further instructions or input from the user.
What does ALU stand for? What is its corresponding component in the Little Man Computer? What does CU stand for? What is its corresponding LMC component?
ALU stands for Arithmetic Logic Unit. In the Little Man Computer, its corresponding component is the accumulator, which performs arithmetic and logical operations.
CU stands for Control Unit. In the LMC, its corresponding component is the program counter (PC), which keeps track of the memory address of the next instruction to be fetched.
What is the purpose of the instruction register? What takes the place of the instruction register in the LMC?
The purpose of the instruction register is to hold the current instruction being executed by the CPU. In the LMC, the instruction register is replaced by the accumulator (ACC), which also holds the current instruction during execution.
There are four primary operations that are normally performed on a register. Describe each operation.
Load: Copies a value from memory into a register.
Store: Copies a value from a register into memory.
Transfer: Moves a value from one register to another.
Arithmetic/Logical Operations: Perform arithmetic or logical operations on the data stored in the register.
If the memory register for a particular computer is 32 bits wide, how much memory can this computer support?
If the memory register for a computer is 32 bits wide, the computer can support 2^32 memory locations, which is equal to 4 gigabytes of memory.
Registers perform a very important role in the fetch–execute cycle. What is the function of registers in the fetch–execute instruction cycle?
Registers play a crucial role in the fetch-execute instruction cycle by facilitating the movement and temporary storage of data and instructions within the CPU. They serve several functions:
Temporary Storage: Registers temporarily hold data and instructions fetched from memory or generated within the CPU during execution. This allows for quick access and manipulation of data without needing to repeatedly access slower memory.
Operand Storage: Registers store operands used in arithmetic and logical operations, allowing the CPU to perform calculations efficiently.
Addressing: Registers, such as the program counter (PC) and memory address register (MAR), hold memory addresses used to access instructions and data in memory during the fetch phase of the cycle.
Instruction Decoding: Registers, like the instruction register (IR), hold the current instruction being executed, allowing the CPU to decode and execute it properly.
Once the fetch operation is complete, what is the first step of the execution phase for any instruction that accesses a memory address for data (e.g., LOAD, STORE)?
Once the fetch operation is complete, the first step of the execution phase for any instruction that accesses a memory address for data is to retrieve the data from the memory location specified by the instruction. This involves accessing the memory location specified by the memory address register (MAR) and transferring the data to the memory data register (MDR) for further processing.
What operations would you expect the arithmetic class of instructions to perform?
The arithmetic class of instructions typically performs mathematical operations such as addition, subtraction, multiplication, and division. These instructions manipulate numerical data stored in registers or memory locations.
What do program control instructions do? Which LMC instructions would be classified as program control instructions
Program control instructions alter the sequence of program execution by controlling the flow of instructions. Examples include unconditional and conditional branching instructions, as well as subroutine call and return instructions. In the LMC, instructions such as BRANCH, BRANCH IF ZERO, and HALT would be classified as program control instructions.
What is a privileged instruction? Which LMC instructions would normally be privileged?
A privileged instruction is one that can only be executed by privileged processes or the operating system kernel. These instructions typically perform sensitive operations that could impact system stability or security. The HALT instruction is usually privileged, because you would not want an individual user to stop the computer while other users are still in the middle of their tasks.
What is the major performance advantage that results from the use of multiple general-purpose data registers?
The major performance advantage of using multiple general-purpose data registers is that they allow the CPU to store and access data directly within the CPU, which is faster than accessing data from the main memory. It also enables parallelism, as multiple data items can be loaded into several registers and processed simultaneously.
Explain how pipelining serves to reduce the average number of steps in the execution part of the fetch–execute cycle.
Pipelining works by having each instruction move through different stages, like steps in a process. Once one step is done, the next instruction starts that step. This means when one instruction finishes, the next one is already partly done. Pipelining reduces the average number of steps in the fetch-execute cycle by allowing multiple instructions to overlap in execution. As a result, more instructions are processed simultaneously, leading to faster overall execution times
Most CPUs today are superscalar. What does that mean?
Superscalar refers to the ability to process more than one instruction per clock cycle. This increases the throughput by double or more.
What is a rename register? What is it used for?
A rename register is a part of a CPU's hardware used to support out-of-order execution, a feature that allows instructions to be executed more efficiently by reordering them. The rename register holds the results of speculative instructions (instructions that are executed before it's certain that they are needed) until those instructions are completed and it's confirmed that the results are needed.
What specific performance improvement is offered by the use of cache memory?
The use of cache memory significantly improves the speed of data retrieval.
Explain the hit ratio in cache memory.
The hit ratio in cache memory refers to the proportion of data accesses that result in data being found in the cache. In other words, it's the ratio of the total number of cache hits (when requested data is found in cache memory) to the total number of memory accesses.
Explain what takes place when cache memory is full.
When cache memory is full, new data that needs to be cached will cause existing data to be evicted from the cache. The cache controller decides which data to evict based on a specific algorithm, such as Least Recently Used (LRU) or First-In, First-Out (FIFO).
When a system has multiple levels of cache memory, L2 always has more memory than L1. Why is this necessary?
When a system has multiple levels of cache memory, L2 always has more memory than L1 because it serves as a backup for L1. L1 cache is faster but smaller and is used for the most frequently accessed data. L2 cache, being larger, can store more data but with a slightly slower speed. This hierarchy allows for an efficient balance between speed and storage capacity, improving overall system performance.
Identify and briefly explain two different ways of configuring a multiprocessing system. Which configuration is more effective for general‐purpose computing? Which configuration is more effective for handling specialized processing tasks, such as those used in game applications?
There are two primary ways of configuring a multiprocessing system: symmetric multiprocessing (SMP) and asymmetric multiprocessing (AMP).
In SMP, all processors are peers; no master-slave relationship exists between processors. Each processor performs all tasks within the operating system. SMP is more effective for general-purpose computing as any idle processor can be assigned any task, and the load balancing between the processors is handled by the operating system.
In AMP, each processor is assigned a specific task. A master processor controls the system; the other processors either look to the master for instruction or have predefined tasks. This makes AMP more suitable for specialized processing tasks, such as those used in game applications where certain tasks can be assigned to specific processors to optimize performance.
In terms of the nature of the data, how does a keyboard differ from a hard disk as an input device?
A keyboard and a hard disk differ significantly in terms of the nature of data they handle as input devices. A keyboard is a manual input device where data is entered in a discrete manner, i.e., one keypress corresponds to one character or function. The data input from a keyboard is generally textual or command-based.
On the other hand, a hard disk, while not typically classified as an input device, can read data stored on it. The data on a hard disk is digital and stored in a binary format. It can handle complex and large volumes of data, including files, applications, and system data. Unlike a keyboard, data retrieval from a hard disk is not manual and can be performed by the system as needed.
Explain the purpose of a buffer
The speed disparities between devices and the CPU can pose synchronization challenges. Therefore, using a buffer could be advantageous. It helps control the data flow and mitigates the effects of latency or speed differences, thereby enhancing system performance.
When an interrupt occurs, what happens to the program that is currently executing at the time?
When an interrupt occurs, the current program is temporarily paused, and the computer jumps to an interrupt processing program to address the event. After handling the interruption, the computer resumes the interrupted program's execution.
The book lists four primary uses for interrupts. State and explain at least three of them.
Three primary uses for interrupts are:
Allocating CPU Time: An interrupt signals the CPU to temporarily stop a running process, allowing another process to use the CPU. This helps in multitasking and efficient use of CPU time.
Completion Signal: When an I/O operation is completed, an interrupt is sent to inform the CPU. This allows the CPU to perform other tasks while waiting for the I/O operation to complete.
External Event Notifier: Interrupts can be used to notify the CPU about external events that require immediate attention, for example, a user pressing a key on the keyboard.
What does DMA stand for? What capability does DMA add to a computer?
DMA stands for Direct Memory Access. It adds the capability for devices to access the main system memory directly without involving the CPU. DMA allows the CPU to be utilized more fully during I/O operations.
What data must an I/O controller have before a DMA transfer takes place? How is this data sent to the controller?
Before a DMA transfer takes place, the I/O controller needs to know the following data: the start address of the memory, the direction of the data transfer (whether it's reading from or writing to memory), and the number of bytes to be transferred. This information is typically sent to the controller by the CPU during the I/O setup phase.
A graphics card is an example of an I/O controller. I/O controllers have (at least) two interfaces. What are the two interfaces of a graphics card connected to?
A graphics card, as an I/O controller, typically has two interfaces. One is connected to the system bus (or PCI Express slot in modern systems) on the motherboard, allowing it to communicate with the CPU and system memory. The other is connected to the monitor or display device, allowing it to output video and graphical data to the screen.
Define a bus. What are buses used for?
A bus in computing is a communication system that transfers data between components inside a computer, or between computers. It is essentially a shared digital pathway connecting multiple hardware components. Buses are used for transferring data, addressing, control signals and power within a computer or to external devices.
Explain how data travels on a bus when the bus is Simplex, Half‐duplex, Full‐duplex.
In a Simplex bus, data travels in only one direction. This means information can either be sent or received, but not both.
In a Half-duplex bus, data can travel in both directions, but not simultaneously. It can either send or receive data at any given time, not both.
In a Full-duplex bus, data can travel in both directions simultaneously. It allows for data to be sent and received at the same time, enhancing communication speed.
Briefly describe each of the major disadvantages of parallel buses.
Parallel buses have several disadvantages:
Increased complexity and cost due to multiple wires.
Synchronization issues with increasing speed.
Crosstalk due to close proximity of lines.
Larger size and higher power consumption than serial buses.
Reasons why storage in a computer is organized hierarchically include:
Faster access to frequently used data: By organizing data hierarchically, commonly accessed data can be stored in faster, more expensive storage mediums, reducing access times.
Cost-effectiveness: Higher levels of the hierarchy typically involve faster but more expensive storage devices, while lower levels involve slower but cheaper storage devices. This allows for a balance between performance and cost.
Scalability: Hierarchical organization enables easy expansion and scaling of storage capacity as needed, accommodating the growing storage demands of modern computing systems.
Suppose a disk is rotating at 7200 rpm. What is the minimum latency time for this disk? What is the maximum latency time for this disk?
The latency time for a disk rotating at 7200 rpm (revolutions per minute) can be calculated using the formula:
Latency time = 1 / (RPM / 60)
Where RPM is the revolutions per minute.
For a disk rotating at 7200 rpm:
Minimum latency time = 1 / (7200 / 60) = 1 / 120 = 0.0083 minutes or approximately 0.5 seconds
Maximum latency time occurs when the disk completes a full rotation:
Maximum latency time = 1 / (7200 / 60) = 1 / 120 = 0.0083 minutes or approximately 0.5 seconds
How does the layout of a typical optical disk differ from that of a magnetic disk? How many tracks does a standard single‐layer CD‐ROM contain?
The layout of a typical optical disk differs from that of a magnetic disk in several ways:
Optical disks use pits and lands to represent data, while magnetic disks use magnetic fields.
Optical disks are read using lasers, while magnetic disks are read using magnetic heads.
Optical disks typically have a single spiral track starting from the center and moving outward, while magnetic disks have multiple concentric tracks.
A standard single-layer CD-ROM contains approximately 333,000 tracks.
What do the numbers 1920 × 1080 represent when describing a display?
The numbers 1920 × 1080 represent the resolution of a display in pixels. Specifically, 1920 pixels in width and 1080 pixels in height. This resolution is commonly known as Full HD or 1080p.
A recent Apple iPad has a resolution of 2048 × 1536 and a diagonal scan size of 9.7 inches. What is the picture ratio of this display? What is the pixel density?
The picture ratio of a display is the ratio of its width to its height. For a display with a resolution of 2048 × 1536, the picture ratio can be calculated as:
Picture ratio = Width / Height = 2048 / 1536 ≈ 1.3333
This indicates that the display has a picture ratio of approximately 4:3.
Pixel density can be calculated using the formula:
Pixel density = √(Width^2 + Height^2) / Diagonal scan size
For the iPad with a resolution of 2048 × 1536 and a diagonal scan size of 9.7 inches:
Pixel density = √(2048^2 + 1536^2) / 9.7 ≈ 264 pixels per inch (PPI)
Explain the purpose of a GPU. What is the relationship between the CPU and a GPU and the display?
The GPU, or Graphics Processing Unit, is a specialized electronic circuit designed to accelerate the creation and rendering of images, videos, and animations. It offloads graphical tasks from the CPU, allowing for smoother and faster rendering of graphics-intensive applications such as games, video editing, and 3D modeling.
The CPU primarily handles general-purpose computing tasks, while the GPU focuses specifically on rendering graphics. The GPU works in tandem with the CPU and sends processed graphical data to the display for visualization.
What does OLED stand for? How does OLED technology differ from LCD technology?
OLED stands for Organic Light-Emitting Diode. OLED technology differs from LCD (Liquid Crystal Display) technology primarily in how they produce light and display images:
In OLED displays, each pixel emits its own light, allowing for deeper blacks and more vibrant colors. This is because OLED pixels can be individually turned on or off.
In LCD displays, a backlight shines through a liquid crystal layer to produce colors. This can lead to less accurate color reproduction and limited contrast compared to OLED displays.
What is the measure used to indicate the resolution of a printer?
The measure used to indicate the resolution of a printer is typically expressed in dots per inch (dpi). This refers to the number of individual dots of ink or toner that the printer can produce per linear inch.
What does NIC stand for?
NIC stands for Network Interface Card. It is a hardware component that allows a computer to connect to a network, such as a local area network (LAN) or the internet. The NIC handles the physical connection to the network, including tasks such as transmitting and receiving data packets.
Explain what is meant by synergy.
Synergy refers to the concept where individual components, such as the CPU, memory, I/O modules, and their connections, are designed to work together in a way that enhances the overall performance of a computer system beyond the performance of each component individually. It is the result of system integration where considering the system as a whole allows for further advances in performance.
What is the purpose of a bus interface or bus bridge?
The purpose of a bus interface or bus bridge is to communicate between different parts of the computer. It serves as a connector and translator, allowing data to be passed between systems that operate at different speeds or use different protocols. For example, a bus bridge might connect the CPU and the memory, or different parts of the motherboard. It ensures smooth and efficient data transfer within the computer system.
What is the predominant master bus found on modern personal computers? What advantages does this bus offer over other buses?
The predominant master bus found on modern personal computers is the PCI Express (Peripheral Component Interconnect Express) bus. This bus offers several advantages over other buses:
High-Speed: PCI Express bus provides a high-speed point-to-point connection, allowing for faster data transfers.
Scalability: PCI Express is scalable and can handle more data lanes, improving overall system performance.
Flexibility: PCI Express slots are backward compatible, meaning they can support devices designed for earlier versions of PCI Express.
Concurrent Data Transfers: Unlike older bus types that could only handle one transaction at a time, PCI Express can handle multiple concurrent transactions, increasing efficiency.
What are the advantages of USB3 as a means to connect peripheral devices to the computer?
USB3, or USB 3.0, offers several advantages for connecting peripheral devices to a computer:
Faster Data Transfer: USB 3.0 offers a significant increase in data transfer speed (up to 5 Gbps), which is approximately 10 times faster than its predecessor, USB 2.0.
Improved Power Efficiency: USB 3.0 uses less power when idle and provides more power for devices that need it.
Increased Bandwidth: USB 3.0 provides bidirectional communication, meaning it can read and write data simultaneously, which enhances its performance.
Backward Compatibility: USB 3.0 is backward compatible with USB 2.0, meaning previous USB devices can still be used with a USB 3.0 port.
What are the advantages offered by I/O channel architecture, such as that used on mainframe computer systems, over bus architecture?
I/O channel architecture offers several advantages over bus architecture:
Higher Performance: I/O channels can perform data transfers in parallel, which can significantly increase system performance.
Reduced CPU Load: By offloading data transfer tasks to an I/O channel, the CPU is freed up to handle other tasks, which can also improve system performance.
Greater Flexibility: I/O channels can be dedicated to specific devices or device types, allowing for more tailored and efficient data transfers.
Scalability: As the system's needs grow, additional I/O channels can be added to accommodate increased data transfer requirements.
Peripheral devices can be categorized into three classes. What are the three classes? Give an example of each.
The three classes are input devices, output devices, or storage devices. Some examples are; input data is data from the outside world into the CPU, and output data is data moving from the CPU out to the outside world, and storage device example would be database files.
What is the advantage of flash memory over RAM? What is the advantage of RAM over flash memory? What is the advantage of flash memory over magnetic hard disk?
An advantage for using flash memory is flash memory uses a special type of transistor that can hold data indefinitely without power. RAM is relatively inexpensive, disk and tape storage is much cheaper yet. The advantage for flash memory over magnetic hard disk is it may be used for off‐line archiving, for moving data easily from machine to machine, and for off‐line backup storage.
What is a disk array? What advantages does a disk array offer over those of a single disk?
Grouping of two or more disk drives. Disk array can be used to reduce overall data access time by sharing the data among multiple disks and also to increase system reliability by providing storage redundancy.
What are the advantages and disadvantages of magnetic tape as compared to other peripheral storage devices?
The advantages of magnetic tape are convenience. They are easy to mount and dismount, and small and easy to store. Tape is nonvolatile, and, under proper storage conditions, the data can be stored indefinitely.
How many pixels are there in a 1024 × 768 display? What is the picture ratio of this display?
a) Total Pixels = 1024 x 768 = 786,432 pixels
b) Aspect ratio = 1024 / 768 = 4/3. Therefore the ratio is a 4:3
What is true of the red, blue, and green pixel values if the color of the pixel is white? What if it's black?
Together, the red, blue, and green pixel values create the desired color on the screen. For a black-and-white image, a single bit per pixel can represent the
Explain how a raster scan works.
In raster scan system electron beam sweeps across the screen, from top to bottom covering one row at a time.A pattern of illuminated pattern of spots is created by turning beam intensity on and off as it moves across each row. memory area called refresh buffer or frame buffer stores picture definition. This memory area holds intensity values for all screen points.
What are the two types of printers in primary use today?
Laser printer or Inkjet printer.
Name at least three user input devices other than touch screens that are commonly found in smartphones and other mobile devices.
A microphone for audio input and an image sensor for photographic images and video input, as well as speakers and headphone jacks for audio output.
What are the five basic hardware components that make up a computer?
The 5 components are:
The CPUs or CPU
The I/O peripheral devices
Memory
I/O modules, controllers, or I/O channel subsystem units
The buses connecting the various components together
Explain what you expect to find on a motherboard.
The CPU, memory, and other major components are mounted to wiring on a printed circuit board (which is the motherboard)
What are major similarities and differences between the PCI‐Express bus and the PCI bus?
both are standards used to connect peripheral devices to a computer, allowing them to access system memory; however, the key difference is that PCIe offers significantly higher bandwidth and faster data transfer speeds due to its serial data transmission design compared to PCI's parallel bus architecture
What is a topology? Describe the basic USB3 topology. Describe the basic Thunderbolt topology.
Topology is when devices are hot pluggable. This means that they can be added and removed at any time without powering down the system. USB3 is built on a hierarchical, hub‐based structure that clearly identifies a single host. Thunderbolt devices share the bus in a manner similar to a network. There may be multiple hosts. The Thunderbolt protocol establishes means for multiple hosts to access the bus without conflict.
What are the advantages of SoC (system on chip) over the traditional architectural layout of a motherboard? What type of computing devices benefit greatly from the incorporation of SoC?
The advantages of SoC allow the entire computer system may be integrated onto a single chip. SoC (a single chip) gives the functions of the southbridge. Operating as a consolidated I/O controller, chipsets are connected to the CPU(s) through a high‐speed bus.
When data is input to a computer, it is nearly always manipulated and stored in some standard data format. Why is the use of data standards considered important, or indeed, crucial in this case?
It is very important to have data standards because through different computer systems, it is important that they are compatible to different systems. It also allows for different data to be seamlessly shared across various systems.
What is the relationship between the ASCII Latin‐1 character set and its Unicode equivalent that makes conversion between the two simple?
When converting between ASCII to Unicode is simple because; for UTF-16 and UTF-32 you only need to extend the 8 bit code to either the 16 bits or 32 bits by setting the ost significant bits to zero. Unicode to ASCII is also simple if the characters used are limited to the ASCII subset.
What are the major characteristics of a bitmap image? What are the major characteristics of an object or vector image? Which is used for displays? What types of images must be stored and manipulated as bitmap images? Why?
Bit map images
Used for realistic images with continuous variations in shading color shape and texture
larger storage requirements
resolution of output limited by resolution image
enlarging image produces jagged edges
preferred when image contains large amounts of detail and processing requirements are fairly simple
input devices - scanners, digital cameras and video capture devices, graphical input devices like mice or pens
Managed by photo editing software or paint software
Each individual pixel, for pixcture elements in graphic is stored as a binary number
Object image
Created by drawing software or drawing features of Microsoft applications such as charts, shapes, and SmartArt
Composed of lines and shapes in various colors
Computer translates geometric formulas to create the graphic
scales smoothly
resolution of output by output device
Storage space depends on image complexity
Based on mathematical formulas
Require less storage space than bitmaps
Cannot represent photos or paintings
Cannot be displayed or printed directly—must be converted to bitmap
Name two advantages to the use of object images.
2 advantages of an object image is that they require less storage and space and they can be manipulated easier without losing their identity.
Explain briefly how an A‐to‐D converter converts audio data into binary data.
Sampling: The continuous audio signal is sampled at regular intervals, typically thousands of times per second (sample rate), to capture its amplitude at discrete points in time.
Quantization: Each sampled point is assigned a specific value based on its amplitude. The amplitude is divided into levels, and the closest level to the sampled value is chosen.
Encoding: The quantized values are then converted into binary format, creating a digital representation of the audio signal. The more bits used, the more precise the representation.
Explain the difference between lossless and lossy data compression. Which type normally provides a smaller file? What is “lost” in lossy audio data compression? Under what circumstances is it impossible to use lossy data compression?
A lossless algorithm compresses the data in such a way that the application of a matching inverse algorithm restores the compressed data exactly to its original form.
Lossy data compression algorithms operate on the assumption that the user can accept a certain amount of data degradation as a trade‐off for the savings in a critical resource such as storage requirements or data transmission time. Lossy data compression depends on the tolerable level of sound quality, but also on the nature of the audio being compressed.
Name five simple data types that are provided in most high‐level programming languages.
The five simple data types are Boolean, char, enumerated data types, integer, and real or float.
The x86 series is an example of a CPU architecture. As you are probably aware, there are a number of different chips, including some from different manufacturers even, that qualify as x86 CPUs. What, exactly, defines the x86 architecture? What word defines the difference between the various CPUs that share the same architecture? Name at least one different CPU architecture.
The main difference between ARM and x86, two types of computer processors, is in their instruction sets: ARM uses a more straightforward system called RISC (Reduced Instruction Set Computing), which helps save energy and makes instructions fast and easy. This is why ARM is great for battery-powered devices like smartphones. On the other hand, x86 uses a more complex system called CISC (Complex Instruction Set Computing). This can do a lot of tasks at once but makes the processor more complicated and expensive to create.
Explain the advantage in implementing separate fetch and execute units in a CPU. What additional task is implemented in the fetch unit as a performance enhancement measure?
units can operate in parallel
Which class of instructions can reduce performance by potentially invalidating the instructions in a pipeline? Identify two methods that can be used to partially overcome this problem.
The fetch execute cycle. The first method to combat this is predicting the direction of branch instructions to keep the pipeline full, or allow the CPU to execute instructions out of their original order to avoid pipeline stalls. If an instruction is delayed due to a branch or data dependency, other independent instructions can be executed instead.
The use of multiple execution units can improve performance but also cause problems called hazards or dependencies. Explain how a hazard can occur. How can hazards be managed?
A hazard/dependency occurs when an Out‐of‐order instruction execution can cause problems because a later instruction may depend on the results from an earlier instruction. The solution for this is CPUs can actually search ahead for instructions without apparent dependencies, to keep the execution units busy.
What performance improvement is offered by memory interleaving?
Memory interleaving is provides improvement by increasing the effective rate of memory access is to divide memory into parts.
Describe how cache memory is organized. What is a cache line? How is it used?
Cache memory is organized into blocks. Each block provides a small amount of storage, perhaps between 8 and 64 bytes, this is what is known as the cache line. The block will be used to hold an exact reproduction of a corresponding amount of storage from somewhere in main memory. Each block also holds a tag. The tag identifies the location in main memory that corresponds to the data being held in that block.
Explain the difference between cache write‐through and cache write‐back. Which method is safer? Which method is faster?
Cache write through and cache write back are two different methods of handling the process of returning changed data from cache to main storage are in common use.
Cache Write Through: writes data back to the main memory immediately upon change in the cache. This method has the advantage that the two copies, cache and main memory, are always kept identical.
Cache Write Back: is faster, since writes to memory are made only when a cache line is actually replaced, but more care is required in the design to ensure that there are no circumstances under which data loss could occur.
Explain the locality of reference principle and its relationship to cache memory performance and the hit ratio.
The locality of reference principle states that at any given time, most memory references will be confined to one or a few small regions of memory.
The hit ratio is an important measure of system performance. Cache hits can access memory data at or near the speed that instructions are executed, even with sophisticated instruction steering and multiple execution units. When a miss occurs, however, there is a time delay while new data is moved to the cache.
Modern computers are usually described as multicore. What does this mean? Under ideal conditions, what performance gain would be achieved using a four‐core processor over a single‐core processor?
When multiple CPU processors are supplied within a single integrated circuit. A dual‐core processor effectively doubles the number of instructions executed in a given time, a quad‐core processor would quadruple the rate, and so forth.
Name at least two devices that can generate unexpected input.
Mice and touchpads
Explain the reasons why programmed I/O does not work very well when the I/O device is a hard disk or a graphics display.
these devices require high data transfer rates and can lead to CPU inefficiency
What is a context? What does it contain? What is it used for?
Context is a part of memory known as the stack area. This information is known as the program's context, and will make it possible to restart the program exactly where it left off, without loss of any data or program state.
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