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SOME BASIC KEYBOARD SHORTCUT KEYS


WHAT IS INTEGRATED CIRCUIT?


An integrated circuit, or IC, is small chip that can function as an amplifier, oscillator, timer,microprocessor, or even computer memory. An IC is a small wafer, usually made of silicon, that can hold anywhere from hundreds to millions of transistors, resistors, and capacitors. These extremely small electronics can perform calculations and store data using either digital or analog technology.

       Digital ICs use logic gates, which work only with values of ones and zeros. A low signal sent to to a component on a digital IC will result in a value of 0, while a high signal creates a value of 1. Digital ICs are the kind you will usually find in computers, networking equipment, and most consumer electronics.

      Analog, or linear ICs work with continuous values. This means a component on a linear IC can take a value of any kind and output another value. The term "linear" is used since the output value is a linear function of the input. For example, a component on a linear IC may multiple an incoming value by a factor of 2.5 and output the result. Linear ICs are typically used in audio and radio frequency amplification.

WHAT IS INPUT OR OUTPUT DEVICES?

In computing, Input/output, or I/O, is the collection of interfaces that different functional units (sub-systems) of an information processing system use to communicate with each other, or the signals (information) sent through those interfaces. Inputs are the signals received by the unit, and outputs are the signals sent from it. The term can also be used as part of an action; to "do I/O" is to perform an input or output operation. I/O devices are used by a person (or other system) to communicate with a computer. For instance, keyboards and mice are considered input devices of a computer and monitors and printers are considered output devices of a computer. Typical devices for communication between computers are for both input and output, such as modems and network cards.

It is important to notice that the previous designations of devices as either input or output change when the perspective changes. Mice and keyboards take as input physical movement that the human user outputs and convert it into signals that a computer can understand. The output from these devices is treated as input by the computer. Similarly, printers and monitors take as input signals that a computer outputs. They then convert these signals into representations that human users can see or read. (For a human user the process of reading or seeing these representations is receiving input.)

In computer architecture, the combination of the CPU and main memory (i.e. memory that the CPU can read and write to directly, with individual instructions) is considered the heart of a computer, and any movement of information from or to that complex, for example to or from a disk drive, is considered I/O. The CPU and its supporting circuitry provide I/O methods that are used in low-level computer programming in the implementation of device drivers.

Higher-level operating system and programming facilities employ separate, more abstract I/O concepts and primitives. For example, operating system provides application programs with the concept of files. C programming language defines functions that allow programs to perform I/O through streams, such as read data from them and write data into them.

A rare alternative to special primitive functions is the I/O monad that permits programs to just describe I/O, and the actions are carried out outside the program. This is notable because the I/O functions would introduce side-effects to any programming language but now purely functional programming is practical.


WHAT IS OPERATING SYSTEM?


ü  OS is system software, which may be viewed as collection of software consisting of procedures for operating the computer.
ü  It provides an environment for execution of programs (application software).
ü  It’s an interface between user & computer.

WHAT IS CPU?

       The central processing unit or (CPU) is the "brain" of your computer. It contains the electronic circuits that cause the computer to follow instructions from memory.
       The CPU contains three main parts, all housed in a single package (Chip):
      Control Unit (CU)
      Arithmetic Logic Unit (ALU)
      Memory