IT Questions and Answers
Answer the following questions. All questions are compulsory. Total marks in this section are 55.
Q1. The central processing unit (CPU), also called a processor, is the most important component of a computer. It has various components including a Control Unit (CU) and an Arithmetic and Logic Unit (ALU). By carrying out research, explain the following features of processors in relation to multi-tasking, multi-processing and data handling.
- Fetch-Decode-Execute: the basic operational process of a computer. It is the process by which a computer retrieves a program instruction from its memory, determines what actions the instruction dictates, and carries out those actions
- Cache Memory: Random access memory (RAM) that a computer microprocessor can access more quickly than it can access regular RAM. This memory is typically integrated directly with the CPU chip or placed on a separate chip that has a separate bus interconnect with the CPU (Gould et al,. 2016)
- Dual-Core: Refers to a CPU that includes two complete execution cores per physical processor. It has combined two processors and their caches and cache controllers onto a single integrated circuit (silicon chip).
- Control Unit: Is a component of a computer’s central processing unit (CPU) that directs the operation of the processor. It tells the computer’s memory, arithmetic/logic unit and input and output devices how to respond to a program’s instructions
- Buffer: Is a portion of a computer’s memory that is set aside as a temporary holding place for data that is being sent to or received from an external device, such as a hard disk drive (HDD), keyboard or printer. The original meaning of buffer is a cushion-like device that reduces the shock from the contact of two objects. A buffer in a computer system is usually located between two devices that have different speeds for handling data or used when there is a difference in the timing of events. It is analogous to a reservoir, which captures water upstream and then lets it out at controlled speeds intended to prevent the lower river from overflowing its banks. Likewise, a buffer in a computer ensures that data has somewhere to go, i.e., into the buffer temporarily until its ultimate destination becomes available. Buffers have a number of applications in computers. For example, CPUs (central processing units) have far higher speeds than HDDs, and thus data that is to be used by a CPU is first copied from a HDD to a buffer while the CPU is performing other tasks so that it will be available for the CPU to use at high speed, i.e., without wasting the CPU’s time waiting for the data. Most text editors store the file being written or edited in a buffer. The text is transferred to the HDD when it is saved, i.e., data from the buffer is copied over the original file on the HDD, thereby replacing it. Because changes are initially stored in a buffer, all of them will be lost if the computer crashes during an editing session. Thus, it is a good idea to frequently save files that are being worked on.
Q2. An operating system acts as an intermediary between computer hardware and the computer user. It performs various functions to manage both hardware and software. Select any two of the following functions of an operating system and explain how an operating system performs these functions effectively. Suggested word limit for each answer is 200 words (400 words in total for this question).
- Booting the computer: In order for a computer to successfully boot, its BIOS, operating system and hardware components must all be working properly; failure of any one of these three elements will likely result in a failed boot sequence. When the computer’s power is first turned on, the CPU initializes itself, which is triggered by a series of clock ticks generated by the system clock. Part of the CPU’s initialization is to look to the system’s ROM BIOS for its first instruction in the start-up program. The ROM BIOS stores the first instruction, which is the instruction to run the power-on self test (POST), in a predetermined memory address. POST begins by checking the BIOS chip and then tests CMOS RAM. If the POST does not detect a battery failure, it then continues to initialize the CPU, checking the inventoried hardware devices (such as the video card), secondary storage devices, such as hard drives and floppy drives, ports and other hardware devices, such as the keyboard and mouse, to ensure they are functioning properly. Once the POST has determined that all components are functioning properly and the CPU has successfully initialized the BIOS looks for an OS to load. The BIOS typically looks to the CMOS chip to tell it where to find the OS, and in most PCs, the OS loads from the C drive on the hard drive even though the BIOS has the capability to load the OS from a floppy disk, CD or ZIP drive. The order of drives that the CMOS looks to in order to locate the OS is called the boot sequence, which can be changed by altering the CMOS setup. Looking to the appropriate boot drive, the BIOS will first encounter the boot record, which tells it where to find the beginning of the OS and the subsequent program file that will initialize the OS
- Managing security: Operating system security (OS security) is the process of ensuring OS integrity, confidentiality and availability. OS security refers to specified steps or measures used to protect the OS from threats, viruses, worms, malware or remote hacker intrusions. OS security encompasses all preventive-control techniques, which safeguard any computer assets capable of being stolen, edited or deleted if OS security is compromised. OS security encompasses many different techniques and methods which ensure safety from threats and attacks. OS security allows different applications and programs to perform required tasks and stop unauthorized interference. OS security may be approached in many ways, including adherence to the following: Performing regular OS patch updates, Installing updated antivirus engines and software, Scrutinizing all incoming and outgoing network traffic through a firewall and creating secure accounts with required privileges only (i.e., user management)
References
Gould, H., Tobochnik, J., Meredith, D. C., Koonin, S. E., McKay, S. R., & Christian, W. (2016). An introduction to computer simulation methods: applications to physical systems. Computers in Physics, 10(4), 349-349.
