Diagram of Computer Component Interconnection

A Description of the different PC and Macintosh Operating Systems

Windows is based on the Windows NT kernel while Mac OS X is based on Free-BSD/UNIX, something generally considered to be faster and more secure. Windows has a large number of viruses and other malware, while there are no Mac OS X viruses and very little malware. Windows requires more regular maintenance to prevent performance and also is more susceptible to accumulating problems over time, requiring re-installation of the OS.

The normal Pc's uses the Microsoft many advanced operating system. few of them include: windows 1995, windows 98, windows 200, windows NT, Windows XE, Windows 7.

Mac OS X uses Aqua which is less processor intensive. Mac OS X Leopard supports multiple desktop spaces and it has Time Machine to easily backup and restore files with an external hard drive. Frequent hardware modifications can result in prevention of access to Windows and your files/programs. Losing a product key on an old copy of Windows could pose a similar problem. Mac OS X does not require activation or consider the owner to be a thief.

The Relationship between an Application Program, the Operating System and Hardware

The relationship between an application program, the operating system and the hardware is usually shown in the form of a stack of layers as shown below:
1. Application
2. Application Programming Interface (API)
3. Operating System
4. Device Driver
5. Hardware
Most applications depends on the operating system - which is why the operating system will provide a set of programming libraries knows as APIs or SDKs (Software Development Kits) for programmers to use when writing applications.

The APIs is connection between the operating system and the running application. The running application depends on the API to perform essential tasks on the system by getting the operating system what they require. That the main reason behind for a program that is written by using Windows Vista APIs will not run on an Apple Mac without some kind of emulation or help.

As there are many different pieces of hardware, it would be not possible for an operating system to support them all, that’s the main reason hardware will write device drivers for different operating systems, so the operating system knows how to respond to the hardware.

A Description of the Boot Process

The computer's power is first turned on, the CPU initializes itself, which is processed by a series of clock ticks generated by the system clock. CPU's initializes the system's ROM BIOS for the first instruction in the startup program. The ROM BIOS stores the first instruction, which is the instruction to run the power-on self test (POST), in a predetermined memory address. POST begins by checking the BIOS chip and then tests CMOS RAM. If the POST does not detect a battery failure, it then continues to initialize the CPU, checking the inventoried hardware devices (such as the video card), secondary storage devices, such as hard drives and floppy drives, ports and other hardware devices, such as the key board and mouse, to ensure they are functioning properly. Once the POST has determined that all components are functioning properly and the CPU has successfully initialized the BIOS looks for an OS to load.

Once the OS initializes, the BIOS copies its files into memory and the OS basically takes over control of the boot process. Now in control, the OS performs another inventory of the system's memory and memory availability (BIOS already checked one) and loads the device drivers that it needs to control the devices, such as a printer, scanner, optical drive, mouse and keyboard. This is the last stage in the boot process, after that the user can access the system’s applications to perform tasks.

The Functions of a Computer Operating System

The operating system is the core software component of the computer. It performs many functions and acts as an interface between the computer and the outside world. Its hardware is of several component parts including your monitor, keyboard, mouse and various other parts. The operating system provides an interface to these parts using by the name drivers. This is why sometimes when we install a new printer or other piece of hardware, the system will ask us to install more software naming as a driver.

Its main functions include monitoring computer performance, debugging problems, or maintaining parts of the system. And also functions which programs may use to perform specific tasks especially relating to interfacing with computer system components.

The Environment Considerations in Disposal of Computer Hardware and OH+S Considerations in the Use of Computer Equipment

Most electronic waste gives a negative impact on the environment by releasing materials such as lead, mercury or cadmium into the soil, groundwater, and atmosphere.

Many materials used in the construction of computer hardware can be recovered in the recycling process for use in future production. Reuse of tin, Silicon, iron, aluminum and a variety of — all present in bulk in computers — can reduce the costs of constructing new systems. In addition, components frequently contain copper, gold, and other materials valuable enough to reclaim in their own right.

A major computer recycling concern is export of waste to countries with lower environmental standards. Companies may find it cost-effective in the short term to sell outdated computers to less developed countries with lax regulations. It is commonly believed that a majority of surplus laptops are routed to developing nations as "dumping grounds for e-waste". The high value of working and reusable laptops, computers, and components (e.g., RAM) can help pay the cost of transportation for a large number of needed "commodities".

Internal hardware components, cost, image and function

1. Desktop case
It is used as the body for CPU
Price 400 dollars




2. CPU

It is stands for Central Processing Uni
Functions the main duties of the system.
Price: 450 Dollars



3. Mother Board
It functions all the important duties on the system
Price: 350 Dollars.


4. Sound Card
It operates and controls the sound system in the computer.
Price: 500 Dollars