6 Computer System (Communication and Storage) Concept

Dr. Sudhanshu Joshi

Introduction

Computer system incorporates communication among various Input, Process and Output devices. Therefore, transmission of data from one computer to another, or from one device to another is performed by communication devices. A communications device, therefore, is any machine that assists data transmission. For example, modems, cables, and ports are all communications devices. Communications software refers to programs that make it possible to transmit data. The aim of communication is to share information. Therefore, the act of communicating can be viewed as act of information sharing. Intercommunication among computer systems has increased the amount of mutually shared information. Figure 1 illustrates Communication Model involving information sharing.

The figure is rather idealized, since it suggests that there are always two collections of information beforehand, and then a single shared collection of information afterwards. For example, it may be the case that some of the shared information is only generated during the course of the communication, as a result of information already shared. Alternatively, it may be the case that, during or after communication, one computer destroys its copy of the information, since it is transferring its information to the other. However, for any communication, it is possible for an external observer to identify the information that a computer has gained from the communication taking place. A desirable feature of a communication system is that the communicating parties themselves can also be certain of the results of a communication.

Youtube animation I : How does hardware and software communicate

Following YouTube link explains how does hardware and software communicate?https://www.youtube.com/watch?v=rNl9ol_rPMs

The video explains the communication between Hardware and Software with the help of System Resources. There are four types of system resources – 1) Memory Address, 2) Input/output address, 3) Interrupt Request Numbers (IRQ),

4) Direct Memory Access (DMA) Channels. (Source: http://Thecuriousengineer.com)

Checkbox I: The significance of Communication and Storage devices

Checkbox I:

Storage devices:

The hardware component used to store data, instruction s and information permanently are normally called as storage device. It is also called Non-volatile because its contents remain safe when computer is turned off. Examples: Floppy Disk, Zip drive, Hard Disk, USB drives etc.

Communication devices: The Hardware component used to communicate exchange Data, instructions, and information with other computer are called communication devices.

Definition

2.1 Information: The Term information could mean either of the following-

• The communication act of one agent—the term “agent” may refer to any entity ranging from a person or a software component to an organization— informing another agent (e.g., by exchanging messages);
• The knowledge or beliefs of agents as a part of their mental state;
• (Data) objects that represent knowledge or beliefs.

2.2 Computer System:

The next term that we should understand is “system”, which could be defined as a combination of Hardware (Input, Process and Output), software (Application Software and System Software) and interconnecting devices (System Bus etc).

In very simple terms, a computer system is made up of three things:

First, CPU (or central processing unit). It’s like a Postal’s grand central station where decisions are made, and just about everything that wants to go anywhere must get routed through it at some point.

Second, computers have lots of destinations for the data to go (and stay) so it can be used later, which we call its addressable memory. These are kind of like houses with physical addresses, where the pieces of data live when they’re not being processed by the CPU.

Third, there are devices that do stuff with data instead of just storing it (called input and output devices) so we can see or hear what’s going on,or interact with the data in some way.

2.3 System Bus: A system bus is kind of like all the train tracks that connect the CPU (the grand central station) with the computer memory (the houses of addressable data) and with the neat devices that let us interact (like the mouse, keyboard, screen, and audio system).

2.4. Motherboard: In early computer systems, all the data traveled across actual cables, which got pretty messy. Large bundles of wires were organized using bus bars, which is where the term ‘bus’ comes from. Nowadays, most of those wires are typically gold-plated traces (or tiny flat wires) on the computer’s motherboard; a large flat surface that all the electronic stuff gets mounted to. The most critical connection of any computer system is the system bus.

2.4. Universal Serial Bus (USB): Cables are still used in present-day computer systems, in particular to connect external devices. The most common type of connection is a Universal Serial Bus (or USB), which you can probably recognize. Many peripheral devices, such as printers and scanners, use a USB connection.

2.5 Computer working flow: We should understand the inter-linkage between Input, process and Output devices. The intercommunication among these three units combines interaction between users, technology and process.

2.4 Computer Bus

A computer bus transfers data between components of a computer system. In this lesson, we’ll talk about how a system bus works, what it’s useful for, and what aspects of it make for a good overall performance of a computer.

2.5. Users

A user is a person who uses a computer or network service. Users generally use a system or a software product without the technical expertise required to fully understand it. Power users use advanced features of programs, though they are not necessarily capable of computer programming and system administration.

The idea of an external observer of communications is important to understanding the concepts described in this chapter, and subsequent chapters. To fully understand the nature of communications, and the effects of communications, it is necessary to stand back and observe all parties involved in the communication. To allow communication, a channel is necessary. This connects the communicating computers together, and allows flows of information to take place between the computers. For this chapter, a simple model of a communication system will be used. It consists of two computers, connected by a channel.

A communication is an act of information sharing between the two computers via the channel. The channel can be regarded as the component that carries out the functions of the communication system.

In general, a channel must allow information to flow in either direction between the computers, at the same time if necessary. This is important if it is to be used for true sharing of information. However, to illustrate many points as simply as possible, communications will just involve a unidirectional information flow, so that always one computer is sending information to the other. For such communications, a simpler channel can be used. Note that taking sharing of information, rather than just transferring of information, as the basic model is important. This is because it is not possible to model all types of sharing in terms of two directions of transferring: if there are any relationships between the two directional information flows, they cannot be accounted for. Further, the sharing model extends more naturally when more than two computers are taken into account later. To achieve communication between two computers, there are two fundamental issues that need to be addressed. First, it is necessary to have agreement on the type of information that is being shared. Second, it is necessary to have implementation that allows required types of information to be shared using channels that allow different — usually simpler — types of information to be communicated. The implementation work may not just be concerned with achieving communication, but also with achieving it at some particular level of quality.

Checkbox II: How the System Bus works

The system bus is a little bit more complicated than a single train track, but not too much. Think of it as three rails per track, kind of like mass transit trains use. That’s because each track has to carry three different things: data, address, and control. (1) The data are the actual digital pieces of information that need to get somewhere or do something; (2) The address information describes where the data is located and where it needs to go during a particular operation. The control part is like the instructions because data doesn’t know what to do with itself (think ‘Lego Movie’), so this manages the flow of address and data information. That includes which direction for the transfer of information and exactly how data needs to be routed through the computer system.

Different types of information, the system bus actually consists of three buses.

Control Bus – this manages the information flow between components indicating whether the operation is a read or a write and ensuring that the operation happens at the right time.

Address Bus- this determines the location in memory that the processor will read data from or write data to.

Data Bus- This contains the contents that have been read from the memory location or are to be written into the memory location.

Progress Check Points

Question 1: Explain the term “System Communication”

Question 2: What is culture function? Why Culture matters to a business firm

Question 3: How Corporate planning and market positioning is influence by the corporate culture of the firm.

Question 4: What are the major determinants / components of corporate culture

References

• Weill & M. Broadbent “Leveraging the New Infrastructure: How Market Leaders Capitalize on IT” , Harvard Business School Press, May 1998. (Based on a study of 54 businesses in 7 countries over five years).