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República bolivariana de Venezuela I.U.T “Antonio José de Sucre” Mérida estado Mérida

What are computers? Computers are machines that perform tasks or calculations according to a set of instructions, or programs. The first fully electronic computers, introduced in the 1940s, were huge machines that required teams of people to operate. Compared to those early machines, today's computers are amazing. Not only are they thousands of times faster, they can fit on your desk, in your lap, or even in your pocket.

History of computer

The very first programmable computer came into existence beginning in 1936 to 1938, and was known as the Z1. This computer was created by Konrad Zuse of Germany, and is now known today to be the first ever electrical binary programmable computer.

Characteristics of computer • Speed A computer is a very fast device. It can carry out instructions at a very high speed obediently, uncritically and without exhibiting any emotions. It can perform in a few seconds the amount of work that a human being can do in an entire year – if he work day and night and is nothing else.

• Accuracy Accuracy of a computer is consistently high and the degree of accuracy of a particular computer depends on the instructions and the type of processor.

• Versatility Versatility is one of the most wonderful things about computer. Multi-processing features of computer makes it quiet versatile in nature.

• Reliability Computer provides very high speed accompanied by an equality high level for reliability. Thus computers never make mistakes of their own accord.

• Power of Remembering A computer can store and recall any amount of information because of its secondary storage capability.

• Common Data Used One item can be involved in several different procedures or accessed, update and inspected by a number of different users.

• Storage The computers have a lot of a storage devices which can store a tremendous amount of data.

The capabilities and limitations of a computer are like a two edge sword. On one side of the sword, computers can solve very complex calculations at lightening speed saving time. They can also process large amounts of data and can be programmed to do almost an unlimited amount of highly complex functions and processes. The limitations on the other side of the sword is the computer cannot independently think on it's own. While it can be programmed with human logic to analyze and make decisions based on the specific programming it does not have the ability to make a decision on it's own. The computer will never replace the amazing human brain

What is Hardware? Hardware is the physical, tangible components of a computer or other electronic device. The term hardware traditionally refers to the physical components of any technology, which is paired with human or animal power and skill to perform it's function. Computer hardware is usually paired with software to perform it's function, and the two together are referred to as a computer system.

SOFTWARE Software is the non-tangible aspect of a computer that is necessary for it to perform any function. Software includes the programs that instruct the computer what to do, the configuration files where important system information is stored, and user files which hold the end result of the computers' functions. Often, many different layers of software are combined to perform computing tasks, examples of which include the transfer of HTML files via TCP/IP or the operation of a media player running in an operating system.


Mainframe is a High performance Multi User computer system which is the most scalable, available, reliable and secured machine in the world capable of performing some Million Instructions per second (upto 569,632 MIPS)

Applications of mainframe various from computing the Random number series to census, industry and consumer statistics, ERP and financial transaction processing.


A minicomputer, a term no longer much used, is a computer of a size intermediate between a microcomputer and a mainframe. Typically, minicomputers have been stand-alone computers (computer systems with attached terminals and other devices) sold to small and mid-size businesses for general business applications and to large enterprises for department-level operations.

WHAT IS MICROCOMPUTER? Consists of one or more microprocessors, stored program memory known as read-only-memory or ROM, random-access-memory (RAM), input/output logic, and usually one or more data input devices such as keyboard, mice, or stylus, and data output device, such as a screen and printer. Desktop computers and personal computers (PCs) are also known as microcomputers. Contrast to mainframe computer.


Alternatively referred to as the brain of the computer, processor, central processor, or microprocessor, the CPU (pronounced as C-P-U) was first developed at Intel with the help of Ted Hoff in the early 1970's and is short for Central Processing Unit. The computer CPU is responsible for handling all instructions it receives from hardware and software running on the computer.


Is a component of a computer's central processing unit (CPU) which directs operation of the processor. It controls communication and co-ordination between input/output devices. It reads and interprets instructions and determines the sequence for processing the data. It directs the operation of the other units by providing timing and control signals. All computer resources are managed by the CU (Control Unit). It directs the flow of data between the Central Processing Unit (CPU) and the other devices.

Functions of the control unit The control unit implements the instruction set of the CPU. It performs the tasks of fetching, decoding, managing execution and, finally, storing results. The control unit may manage the translation of instructions (not data) to micro-instructions and manage scheduling the microinstructions between the various execution units. On some processors, the control unit may be further broken down into other units, such as a scheduling unit to handle scheduling or a retirement unit to deal with results coming from the pipeline. The control unit handles the main functions of the CPU.

Microprogram control unit The idea of microprogramming was introduced by Maurice Wilkes in 1951 as an intermediate level to execute computer program instructions. Microprograms were organized as a sequence of microinstructions and stored in special control memory. The algorithm for the microprogram control unit is usually specified by flowchart description.[2] The main advantage of the microprogram control unit is the simplicity of its structure. Outputs of the controller are organized in microinstructions and they can be easily replaced.


Arithmetic and logical unit is the actual component of central processing unit where all instructions performing arithmetic and logical operations are actually executed. Data items about to be processed are taken from main storage as directed by the control unit and passed the MBR into the accumulator in the Arithmetic and logical Unit where they are stored. This step is usually referred to as loading data into an accumulator from main storage. We should note at this point that the location address of these data items will have been contained in the IR, from where they were transferred to MAR prior to loading the data.


Primary storage, also known as main storage or memory, is the main area in a computer in which data is stored for quick access by the computer's processor. On today's smaller computers, especially personal computers and workstations, the term random access memory (RAM) - or just memory - is used instead of primary or mainstorage, and the hard disk, diskette, CD, and DVD collectively describe secondary storage or auxiliary storage.


Secondary storage ( secondary memory , auxiliary memory or external memory ) is the set of devices ( apparatus) and means ( media ) storage , which make the memory subsystem of a computer, with the main memory.Do not confuse the "units or storage devices " with " media or storage media " because the former are devices that read or write data stored on the media . Secondary memory is a type of (permanent ) and permanent mass storage , unlike the RAM is volatile , but has larger memory capacity than main memory , although it is slower . Nowadays mainly three storage information ' technology ' are used : 1. Magnetic ( eg, hard disk , floppy disk, magnetic tape ); Two . Optical (eg CD , DVD, Blu -ray Disc, etc. . ) 1. Some devices combine two technologies , namely , hybrids are storage devices , for example . , Zip drives. Three . Flash Memory ( Flash Memory Cards Solid State Drives and SSD) Secondary storage properties [edit • editing code ] • Large storage capacity . • No information is lost in the absence of power . • High -speed transfer of information. • Same format storage in main memory .

Bibliographic references

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