COMPUTER SYSTEMS

Computer Systems

Computer Systems

Introduction

Computers play a major role in providing an maximizing access, minimizing costs, and improving the quality of any organization. The computers modern electronics are an essential tool in many areas: industry, government, science, education, a reality in almost all areas of our lives. The CPU (Central Processing Unit) is the intelligent part of the system. Programs interpret the user instructions and review the status of the inputs. Depending on these states and the program, ordered the activation of the desired outputs. In the system ROM, the manufacturer has recorded a series of executive programs, system software and these programs that will access the micro capacitor to perform those functions (Lamb, 2009, 258).

Basic Functions of a CPU

The software of any PLC system consists of a series of basic functions performed at certain times of each cycle. In general, each controller contains and performs the following functions:

Ensure that the runtime user program does not exceed a certain maximum time. This function is called Watchdog.

Run the user program.

Create an image of entries as the user program must not directly access these entries.

Renew the state of the outputs according to the image of them, obtained at the end of the cycle of user program execution.

Check system.

Computer Peripherals

Peripherals are called all external devices connected to the system unit, such as, for example, monitor , keyboard , mouse , speakers, printer , scanner , or a surge protector (reducing the likelihood of failure of supply, it also usually serves as an extension cord) (Velte, 2008, 85).

It is a term used for devices that are connected to a computer or computer and controlled by its microprocessor. Even though the term peripherals often involve the concept of additional but not essential, many are essential to a computer system. These devices are used to enter information into the computer, and also to remove (Poniatowski, 2009, 148). The features are:

Are exterior

Connect to the computer via special connectors located on the back of the computer, called communication ports.

To allow the CPU to control them, you need a specific software program called device drive (Bardram, 2007, 323)

Characteristics of Peripheral Devices

Each peripheral is usually made ??of two different parts in their mission and operations: some mechanical and other electronics. Part mechanics is primarily made ??electromechanical devices (switches manuals, motors, solenoids, etc.) controlled by electronics.

The electronic part is included mostly in the interface circuits.

The operating speed of a peripheral is given by the mechanical elements.

To be able to effectively use a computer, its operating system contains special routines for management of different types of peripherals. Without these routines would be impossible or extremely complex to use a peripheral from a language of high level. Some peripherals have the ability to autonomously certain operations. These operations range from self-test or verify their physical functioning, to function more complex as rewinding a tape, or draw on a chart recorder information contained on magnetic tape (Joos, 2006, 105).

Besides these, other features of peripherals and information media are:

* Reliability: The probability ...