What is an operating system?
An operating system is the most important software that runs on a computer.
It manages the computer’s memory and processes, as well as all of its software and hardware.
It also allows you to communicate with the computer without knowing how to speak the computer’s language.
Without an operating system, a computer is useless.
Cisco Application Policy Infrastructure Controller (APIC)
The Cisco Application Policy Infrastructure Controller (APIC) is the single point of policy and management of a Cisco Application Centric Infrastructure (ACI) fabric.
Cisco APIC re-defines how Cisco networks are managed and operated.
In traditional Cisco networks, each node is managed independently, via the command-line interface (CLI), which is time-consuming, tedious, and error-prone.
In ACI networks, network admins use the APIC to manage the network they no longer need to access the CLI on every node to configure or provision network resources.
Interrupt handling
Interrupt handling is a key function in real-time software, and comprises interrupts and their handlers.
Only those physical interrupts which of high enough priority can be centered into system interrupt table.
The software assigns each interrupt to a handler in the interrupt table. An interrupt handler is just a routine containing a sequence of operations.
Each of these may request input and output while running.
The von Neumann Model
The von Neumann architecturealso known as the von Neumann model or Princeton architectureis a computer architecture based on a 1945 description by John von Neumann and others in the First Draft of a Report on the EDVAC.
That document describes a design architecture for an electronic digital computer with these components: A processing unit that contains an arithmetic logic unit and processor registers, A control unit that contains an instruction register and program counter, Memory that stores data and instructions, External mass storage, and Input and output mechanisms.
Microprocessor Concepts
Microprocessor is the brain of computer, which does all the work.
It is a computer processor that incorporates all the functions of CPU (Central Processing Unit) on a single IC (Integrated Circuit) or at the most a few ICs.
Microprocessors were first introduced in early 1970s. 4
004 was the first general purpose microprocessor used by Intel in building personal computers.
Arrival of low cost general purpose microprocessors has been instrumental in development of modern society the way it has.
Data Transfer Rate
A data transfer rate tells you how much digital data will travel from one place to anotherfrom a hard drive to a USB flash drive.
However, with todays technology being capable of transferring large amounts of data at fast speeds, youre more likely to see it measured in megabits per second (Mbps) or megabytes per second (MBps).
Sometimeswhen downloading a file from the internet, for instanceyou might see the data transfer rate measured in kilobytes per second (KBps).
Clock
The clock refers to a microchip that regulates the timing and speed of all computer functions.
In the chip is a crystal that vibrates at a specific frequency when electricity is applied.
The shortest time any computer is capable of performing is one clock, or one vibration of the clock chip. The speed of a computer processor is measured in clock speed.
Pipelining
Pipelining is the process of accumulating instruction from the processor through a pipeline.
It allows storing and executing instructions in an orderly process.
It is also known as pipeline processing.
Pipelining is a technique where multiple instructions are overlapped during execution.
Pipeline is divided into stages and these stages are connected with one another to form a pipe like structure.
Instructions enter from one end and exit from another end.
Buffer
A buffer is a data area shared by hardware devices or program processes that operate at different speeds or with different sets of priorities.
The buffer allows each device or process to operate without being held up by the other.
In order for a buffer to be effective, the size of the buffer and the algorithms for moving data into and out of the buffer need to be considered by the buffer designer.
Like a cache, a buffer is a “midpoint holding place” but exists not so much to accelerate the speed of an activity as to support the coordination of separate activities.
Cache
Cache is a type of memory that is used to increase the speed of data access.
Normally, the data required for any process resides in the main memory.
However, it is transferred to the cache memory temporarily if it is used frequently enough.
The process of storing and accessing data from a cache is known as caching.