C191 MY VOCA

CPU (Central Processing Unit)

THIS is like the brain of the computer. It executes instructions to perform tasks. These instructions tell THIS to work with data stored in registers (tiny, super-fast storage inside THIS) and memory locations (other places in the computer’s memory).

For example:

• A program might instruct THIS to add numbers stored in two registers.

• Another instruction might ask THIS to copy data from memory to a register for processing

Main Memory

THIS is the computer’s temporary storage, where programs and data are kept while the computer is working on them. It’s like a workspace for the CPU.

Physical memory is a linear sequence of addressable bytes or words that hold programs and data.

• It’s linear, meaning it’s organized as a sequence of numbered slots, each holding a piece of data.

• Each slot can hold a byte (a small unit of data) or a word (a group of bytes).

For example:

• If you’re writing a document, the text and formatting details are temporarily stored in THIS.

Secondary Storage

Disk and other secondary storage devices are multi-dimensional structures, which require complex sequences of low-level operations to store and access data organized in discrete blocks.

THIS refers to devices like hard drives and SSDs where data is stored permanently (or until you delete it).

I/O Devices

THIS refers to things like keyboards, mice, printers, and monitors that let the user interact with the computer.

• THESE work by reading and writing data to/from device controllers (special hardware that manages the device).

For example:

• Typing on a keyboard sends data (the keys you press) to the CPU.

• Printing sends data (the document) from memory to the printer through the device controller.

Abstraction

THIS is the act of removing unnecessary details from an object to create simpler and more general versions of it.

For example, when you use an app on your phone, you don’t see all the code running behind the scenes. Instead, you just interact with the app in a simple way, like clicking buttons. THIS process hides the complexity and makes the app easier to use.

Operating systems (OS) make heavy use of THIS by organizing many small tasks into larger, easier-to-use actions. They create hierarchies of objects, where multiple operations at a low level are combined into a single action at a higher level, so users only need to think about the bigger picture.

Virtualization

THIS is the act of creating a fake version of something that appears to have better or more useful characteristics than the actual object.

For example:

• In a virtualized environment, one physical computer can act like many separate computers.

• Virtual machines are software versions of computers that seem like real hardware but are running inside another system.

In THIS case, you are making a computer or device appear more powerful or capable than it actually is by simulating features that don’t exist in the physical hardware.

Multiprogramming

THIS is a technique that allows multiple programs to be kept active in memory at the same time. The CPU switches between these programs, giving each one a chance to use the CPU and other resources. This helps the computer maximize efficiency, making sure that while one program is waiting for something (like reading from a file), another program can use the CPU.

For example:

• You might be running a web browser and a word processor at the same time. When the word processor isn’t using the CPU, the browser can use it, making both programs feel fast and responsive.

Time-sharing (Multitasking)

THIS is a more advanced version of multiprogramming. is an extension of multiprogramming where the CPU is switched periodically among all active computations to guarantee acceptable response times to each user.

THIS employs the concept of virtualization by creating the illusion of having a separate virtual CPU for each computation.

Kernel

Is the minimal set of functions necessary to manage the system resources safely and efficiently.

It typically provides the most essential services for memory and device management, for creating and managing units of computation, and for communication among the different concurrent activities within the system

Privileged instruction

An instruction that performs important operations, such as accessing input/output (I/O) devices or controlling the CPU's status and control registers. Only the operating system (OS) kernel is allowed to execute these instructions to maintain system security and stability.