The word computer is derived from the Latin meaning Computare count. In English is called to compute. By definition a computer translated as a collection of electronic tools that work together, can receive data (input), process data (process) and providing information (output) as well as coordinated under the control program stored in its memory.
So how can we describe the computer as follows:
- Input Device, is a computer-hardware device that serves to enter data into computer memory, such as keyboard, mouse, joystick and others.
- Prosesor, is the main device a computer that manages the entire activity of the computer itself. The processor consists of two main parts, namely;
- Control Unit (CU), is a major component of the processor that controls all the devices installed on the computer, starting from the input device to output device.
- Arithmetic Logic Unit (ALU), is part of a special processor data processing arithmetic (add, subtract, etc.) as well as data logic (comparison).
Memory is divided into two kinds, namely;
- Read Only Memory (ROM), which is memory that can only be read alone, can not be changed and removed and has been filled by the manufacturer of the computer. The contents of ROM is required when the computer is turned on. Commands on the ROM will be partially transferred to the RAM. Command that is in ROM include the operating system command to read from disk, the command to check semuaperalatan in the system unit and a command to display the message on the screen. The contents of ROM will not be lost even though there is no electricity. But at this present moment ROM has been progressing and many kinds, including:
- PROM (Programmable ROM), a ROM that we can re-program the notes may only be one change after it can no longer be programmed.
- RPROM (Re-Programmable ROM), an outgrowth of the PROM version where we can make changes repeatedly as expected.
- EPROM (Erasable Program ROM), a ROM yangdapat we delete and re-program, but how to eliminate it by using ultraviolet light.
- EEPROM (electrically erasable program ROM), recent developments of the ROM where we can mengubahdan remove programs by using teknikelektrik ROM. EEPROM is the most widely used today.
- Random Access Memory (RAM), the name we can interpret that the RAM is memory that can be accessed randomly. RAM serves to store the programs that we were for a time (power on) if we turn off the computer, then all data stored in RAM is lost. The purpose of this RAM is to accelerate data processing on the computer. In order for the data that we make can not be lost when the computer is turned off, it would require an external storage media, such as floppy, hard drive, flash disk, PCMCIA cards and others.
4. Output Device, is a computer device that is useful for generating output, whether it's to the paper (hardcopy), to the screen (softcopy) or output a voice. For example a printer, speakers, plotters, monitors and many others. From the above explanation we can conclude that the working principle of the computer begins to enter data from the input device, then the data is processed as such by the CPU according to what we want and the data have been processed is stored in computer memory or disk. The data stored can we see the result through the output device.
