What Is Computer

Computer – is a fast electronic computational device operating under the control of instructions stored in its own memory unit that can accept data(input), perform prescribed operations on the data (processing), produce result from the processing (output), and store the result for the future use (storage). The term computer is derived from the word “compute” that suggests computation or calculation. But this idea is misleading, although this is one of the functions of a computer. A computer can work efficiently if given a proper instruction through a PROGRAM. A program is a set of instructions that tells the computer what to do. This program will not work effectively inside the compute unless somebody (computer user) will manipulate it correctly. Th computer needs outside intervention to work accurately. Advantages of a computer. •

Generates information at high speed

The computer can manipulate a huge amount of data in nanoseconds (1x10-9 seconds); with this the computer user can be more productive because of the tremendous amount of time that can be saved. •

Process data accurately

A computer is reliable. It rarely makes erros. Computer errors are often caused by erroneous input of data. •

Saves and retrieves information

In today’s computer technology, a computer can store a large amount of data through secondary storage devices such as diskettes, hard disks, CD-ROM Disks (Read Only Memory), flash memory cards, magnetic tape, etc. It can also recall information at lightning speed. The information can easily be retrieved from previously stored information, modify it, and then store it again. •

Performs logical operations

A computer can be of great help in solving complex problems that require a certain decision. It can logically manipulate data using logical operators (>, <, +, /, x, =). •

Communicates with other users or with the machine

A computer can actually instruct the user how to debug his work. A certain message is shown on the screen when the users commits an error and doesn’t know what to do. Limitations of Computers •

Cannot generate information on its own.

A computer cannot produce information unless it is fed with correct data or sequence of instruction. The common term in the world of computer is GIGO (Garbage In, Garbage Out). •

Inability to derive its own meaning from objects

Although a computer can perform arithmetic and logical operations, hence can produce output in terms of numbers or letters, it has no capacity to interpret the results. A computer cannot respond to human

emotions, it needs human thinking to analyze the output. For computer, the data fed into it are meaningless. Only the end user can evaluate what the computer produces. •

Cannot come up with orginal decisions

All the information produced by the computer are based on the sequence of instruction fed into it. Nobody can dictate what the computer should produce according to his personal interest. •

Cannot correct wrong instructions

A computer is not capable to filter as it executes only the correct instructions and discards the erroneous ones. It can only prompt the user that an error has been committed in the process of executing the program. Typographical errors can be determined by the computer but it cannot change them in as much as it cannot tell a wrong sequence of instructions. It does only what is tasked to do regardless of what it means. •

Subject to occasional breakdown

Most storage devices, such as hard drives, are mechanical devices, which can become worn out and thus are prone to failure. A storage device is often the first component to malfunction in a computer. When a storage device fails, all the data stored on the device may get lost. COMPUTER TECHNOLOGY Date 1200 AD – ABACUS

1614- NAPIER’S BONE 1632-OUGHTRED’S SLIDE RULE 1642-PASCALINE MACHINE

1694-FIRST CALCULATOR

1780-JACQUARD LOOM

Activity It is the first computing device develop by the Chinese. The abacus is made up of beads or pebbles arranged in rows that represent values to facilitate calculation. Up to the present, some Chinese mechants still use the abacus. Invented by John Napier, it can perform multiplication and divisiion. It contains a set of 11 sticks, which were bones, and used by placing them side by side. Developed by Willian Oughtred, it consists of two movable rules placed side by side. Sliding the rulers can do multiplication and division. Blaise Pascal, a French mathematician, invented this machine. He used the principle of abacus, but instead of moving the beads manually, it worked mechanically and can add and subtract by means of rotating ten-toothed wheels and cogs. Gottfried Wilhelm von Leibnitz improved the work of Pascal. He made a machine that can perform the four fundamental operations (addition, subtraction, multiplication and division) and even extract square roots. Another Frenchman invented the first automatic weaving loom that introduced the use of punched cards. He prepared a stiff card in which the pattern of a weave was encoded using punched holes that indicated where the thread was to pass or skip in a weave.