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The Memory Address Register (MAR) holds the address of the current instruction or data that is to be fetched from or transferred to memory.

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First, evaluate each part of the expression separately:

• \(P \geq Q\) evaluates to \(3 \geq 6\), which is false (0).
• \(P \leq 5\) evaluates to \(3 \leq 5\), which is true (1).

The NOR operation returns true only if both operands are false. Therefore, false NOR true is false (0).

The value of the expression is 0.

Detailed Answer

(a)

• RAM is volatile, meaning it requires power to maintain stored information. When the computer is turned off, data in RAM is lost.
• It temporarily stores data and instructions that are currently being used by the computer.
• RAM allows data to be read, written, and modified.
• Although faster than secondary storage like HDDs or SSDs, RAM typically has a smaller capacity.

(b)

• Cache memory is a very fast type of memory that serves as a buffer between RAM and the CPU.
• It holds frequently accessed data and instructions to make them immediately available to the CPU.
• Cache memory improves system performance and speed by storing instructions and data that are repeatedly required during program execution, thus reducing the need to access slower RAM.
• It is located inside the CPU and can be accessed directly by the processor, helping to minimize the average time to access data from the main memory.

Detailed Answer

Truth table for the logic expression A NAND (B NOR C):

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Cache memory plays a crucial role in enhancing system performance by:

• Being a high-speed memory located between the CPU and RAM.
• Storing frequently accessed data and instructions temporarily to reduce the time it takes for the CPU to retrieve this information.
• Speeding up processing by decreasing access times, as the CPU first looks in the cache before accessing the slower RAM.
• Improving overall system performance and efficiency by minimizing the latency involved in fetching data from main memory.

Detailed Answer

(a)

• Divide 105 by 2, noting the quotient and remainder:
• 105 ÷ 2 = 52 remainder 1
• 52 ÷ 2 = 26 remainder 0
• 26 ÷ 2 = 13 remainder 0
• 13 ÷ 2 = 6 remainder 1
• 6 ÷ 2 = 3 remainder 0
• 3 ÷ 2 = 1 remainder 1
• 1 ÷ 2 = 0 remainder 1
• Read the remainders from bottom to top: 1101001
• Thus, the binary value of 105 is 1101001.

(b)

• Divide 200 by 16, noting the quotient and remainder:
• 200 ÷ 16 = 12 remainder 8
• 12 ÷ 16 = 0 remainder 12
• The remainders are 12 (which is C in hexadecimal) and 8.
• Thus, the hexadecimal value of 200 is C8.

Detailed Answer

Truth table for the logic expression (X XOR Y) AND Z:

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Detailed Answer

The answer can include the following examples:

• Programs written in high-level languages (HLLs) are designed to be human-readable and understandable, featuring syntax and structures that simplify programming tasks. However, these HLLs cannot be directly understood or executed by computer hardware.
• A translation process, involving a compiler or interpreter, converts high-level language code into machine code. This process allows the computer to perform the desired operations as instructed by the program.

Detailed Answer

The answer can include the following examples:

• It provides users with access to information and resources available on the World Wide Web (WWW).
• When a user requests a specific website, the web browser communicates with a web server to retrieve the necessary content.
• The browser acts as an interface between the client (the user) and the server, facilitating the exchange of data.
• It processes and interprets the retrieved data, converting it into a format that can be displayed and understood on the user's device.
• The browser presents the resulting web page, allowing users to view and interact with it.
• Additionally, it provides functionalities such as navigating between web pages, opening multiple tabs, printing pages, saving content, and more.

Detailed Answer

First, evaluate each part of the expression separately:

• \(X \leq 6\) evaluates to \(7 \leq 6\), which is false (0).
• \(Y > X\) evaluates to \(3 > 7\), which is false (0).

The XOR (exclusive OR) operation returns true if exactly one of the operands is true. Therefore, false XOR false is false (0).

The value of the expression is 0.

Detailed Answer

The answer can include the following examples:

• Compressing a data file reduces its size, which directly impacts the efficiency of data transmission.
• Since the time required to send a file across a network depends on its size, a smaller compressed file takes less time to transmit compared to its uncompressed counterpart.
• Reduced file size also leads to decreased network usage, which can lower the financial costs associated with running a network, including expenses related to bandwidth and data handling equipment.
• Overall, compression helps in optimizing network performance, reducing transmission times, and lowering operational costs.

Detailed Answer

• \(A \leq B\) is \(3 \leq 5\), which is true (1).
• \(C > B\) is \(11 > 5\), which is true (1).
• The XOR operation returns true if exactly one of the operands is true. Therefore, true XOR true is false (0).
• \(A < B\) evaluates to \(3 < 5\), which is true (1).
• Finally, false AND true is false (0) because the AND operation returns true only if both operands are true.

The value of the expression is 0.

Detailed Answer

The answer can include the following examples:

• The binary system consists of only two digits, 0 and 1, which aligns with the computer's use of bi-stable devices.
• These bi-stable devices can be in one of two possible states, such as on or off, pulse or no pulse, 0 or 1, true or false.
• This simple binary system allows for reliable and efficient data representation and processing, as it directly corresponds to the physical components and electronic signals within the computer.

Detailed Answer

• Access and Usage:
  • Primary storage (such as RAM and cache) is directly accessed by the computer's central processing unit (CPU) for quick data retrieval and processing.
  • Secondary storage (such as SSDs or HDDs) is not directly accessed by the CPU. Instead, data must be loaded into primary storage before it can be used by the CPU.
• Characteristics and Purpose:
  • Primary storage has a lower access time, smaller capacity, and is more expensive compared to secondary storage. It is volatile, meaning it loses its data when the power is off.
  • Secondary storage has a larger capacity, is less expensive, and is non-volatile, meaning it retains data even when the computer is powered off. It is used for long-term data storage.

Detailed Answer

The answer can include the following examples:

• Reduced Transfer Times: Compression reduces the number of bits needed to represent data, which decreases the amount of data that needs to be transmitted.
• Space Efficiency: By modifying and restructuring files, compression reduces their size, allowing more efficient use of storage space.
• Cost Savings: Smaller file sizes result in reduced costs for cloud storage and network bandwidth, making data transmission more economical.

Detailed Answer

• Fetches data or instructions from the memory.
• Decodes the instructions into actionable steps or signals.
• Directs the flow of data and instructions within the CPU, such as sending commands to the ALU for execution.
• Coordinates and oversees the activities of all computer units to ensure proper functioning.

Detailed Answer

• Cache memory is located closer to the CPU or is integrated into the processor chip, making it quicker to access compared to main memory.
• It stores recently accessed or frequently used data and instructions, reducing the need to fetch them repeatedly from slower main memory.
• This proximity and rapid access improve the overall speed of program execution and data retrieval.

Detailed Answer

3 in hexadecimal is 0011 in binary.

C in hexadecimal is 1100 in binary.

3C in hexadecimal is thus 0011 1100 in binary.

Detailed Answer

Detailed Answer

• The OS allocates and deallocates distinct sections of memory to each program, process, or module.
• This allocation ensures that the memory assigned to one program does not get overwritten by another.
• It utilizes secondary or virtual memory, enabling the system to run more processes concurrently than the physical memory alone could support.

Detailed Answer

• The MAC address uniquely identifies a device, such as a network card or controller, on a network.
• The MAC address is compared against a list of approved addresses or a whitelist. If the address is not on the list, access to the network is denied.
• This system helps prevent unauthorized access, providing an additional layer of security, unless the NIC is cloned.
• Data transmitted to a specific MAC address can only be accessed by the device associated with that address, ensuring targeted communication.

Detailed Answer

Hexadecimal uses 16 possible values for each digit. Thus, the total number of different combinations that can be formed with two hexadecimal characters is the product of the possible values for each digit, which is \( 16 \times 16 = 256 \).

Detailed Answer

(a)

• RAM serves as temporary storage for data, instructions, and programs that are currently running, including the operating system and applications.
• ROM is permanent memory, storing instructions and data that remain unchanged, particularly the boot-up instructions for the computer.
• Both read and write operations can be performed on RAM, while ROM supports only read operations.
• If there is a power failure during RAM access, all data is lost, as RAM is volatile. In contrast, ROM is non-volatile, so no data will be lost if power is lost during access.

(b)

• The OS memory manager assigns a block of memory to a program when requested.
• When a program no longer requires the data in allocated memory, it becomes available for reassignment.
• The OS ensures there is always enough memory for the data structures and objects of running programs.
• Once the program finishes, its allocated memory is freed and can be used by other programs.
• The OS uses virtual memory, which allows secondary storage to be used for programs that need more memory than what is available in RAM.
• After the program execution, the memory is reallocated or freed for use by other programs.

(c)

• The bus is a system used to transfer data between hardware components. The data bus and address bus allow the processor to communicate with primary memory.
• When the processor fetches an instruction, it uses the address bus to specify the physical address of the memory block it needs to access.
• The processor retrieves data from the specified memory block by checking the address bus for the read address.
• This data is then placed on the data bus, which carries the data to the processor.
• When storing results in memory, the processor sets the write address on the address bus and places the data to be written onto the data bus.

Detailed Answer

Arithmetic and Logic Unit (ALU)

Detailed Answer

10011100 can be divided into 1001 and 1100.

1001 in binary is 9 in hexadecimal.

1100 in binary is C in hexadecimal.

The hexadecimal equivalent of the binary number 10011100 is 9C.

Detailed Answer

a) Each color uses 8 bits, so: \( 8 \times 3 = 24 \)

b) We have 256 possibilities for 3 colors, so: \( 256^3 = 16777216 \)

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