PC is basically the acronym for personal computer that is used by an individual in his home. A PC may either be a desktop computer, a laptop or tablet machine. A PC may be used for any general purpose and some of the most common operating systems for personal computers are Linux, Microsoft Windows and Mac. Most personal computers have options for high-speed internet accessibility and multimedia capabilities.
Personal computers have developed at a fantastic pace and earlier users had to write their own programs. Today, however, there is no dearth of programs for all sorts of tasks from gaming to data management for PCs.
It was in the 1980s that Microsoft and Intel started dominating the personal computer market. Just a few years earlier, Apple Inc. was set up too. Eventually, when Apple launched its own personal computer, the MacBook, apart from its iPods and iPhones, the personal computing market was split into two.
Alongside a media blitz, Apple Inc offered its personal computers with their own Mac operating systems. So, while the rest of the market had personal computers with the Windows operating software, Apple decided to hold its own. Soon, referring to a Mac meant the Apple personal computer and referring to a PC meant referring to a non-Apple personal computer! This has also led to the current confusion about the differences between a PC and a Mac. Essentially, the Mac is a personal computer too! But the branding is what makes all the difference.
Reference:
http://www.differencebetween.net/technology/difference-between-pc-and-mac/
Friday, May 7, 2010
4.6. The Relationship between an Application program, the operating system and hardware
The relationship between an application program and the underlying hardware is usually shown in the form of a stack of layers as shown below:
Application
Application Programming Interface (API)
Operating System
Device Driver
Hardware
Most applications need to know how to talk to 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 sit between the operating system and the running application. The running application relies on the API to perform essential tasks on the computer by telling the operating system what it wants to do - which is why a program that is written to use Windows Vista APIs will not run on an Apple Mac without some kind of emulation or help.
Because there are so many different pieces of hardware, it would be impossible for an operating system to support them all (especially the lesser known devices). That's why hardware manufacturers will write device drivers for different operating systems, so the operating system knows how to talk to the hardware.
Application
Application Programming Interface (API)
Operating System
Device Driver
Hardware
Most applications need to know how to talk to 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 sit between the operating system and the running application. The running application relies on the API to perform essential tasks on the computer by telling the operating system what it wants to do - which is why a program that is written to use Windows Vista APIs will not run on an Apple Mac without some kind of emulation or help.
Because there are so many different pieces of hardware, it would be impossible for an operating system to support them all (especially the lesser known devices). That's why hardware manufacturers will write device drivers for different operating systems, so the operating system knows how to talk to the hardware.
Tuesday, May 4, 2010
4.5. A Description of the Boot Process
Mac OS X system :
When the power to a Macintosh computer is turned on, the BootROM firmware is activated. BootROM (which is part of the computer’s hardware) has two primary responsibilities: it initializes system hardware and it selects an operating system to run. BootROM has two components to help it carry out these functions:
POST (Power-On Self Test) initializes some hardware interfaces and verifies that sufficient memory is available and in a good state.
On PowerPC-based Macintosh computers, Open Firmware initializes the rest of the hardware, builds the initial device tree (a hierarchical representation of devices associated with the computer), and selects the operating system to use.
On Intel-based Macintosh computers, EFI does basic hardware initialization and selects which operating system to use.
If multiple installations of Mac OS X are available, BootROM chooses the one that was last selected by the Startup Disk System Preference. The user can override this choice by holding down the Option key while the computer boots, which causes Open Firmware or EFI to display a screen for choosing the boot volume.
Reference:
http://developer.apple.com/mac/library/documentation/MacOSX/Conceptual/BPSystemStartup/Articles/BootProcess.html
Linux 9 system:
The beginning of the boot process varies depending on the hardware platform being used. However, once the kernel is found and loaded by the boot loader, the default boot process is identical across all architectures. This chapter focuses on the x86 architecture.
Reference:
http://www.redhat.com/docs/manuals/linux/RHL-9-Manual/ref-guide/s1-boot-init-shutdown-process.html#S3-BOOT-INIT-SHUTDOWN-OTHER-ARCHITECTURES
Windows system:
When the system is turned on, the BIOS runs self-test diagnostics to verify the system's hardware and memory. The system begins to boot automatically if no errors are found. If errors are found, error messages are displayed that describe recovery options.
The BIOS of additional hardware devices are run at this time.
The BIOS boot program tries to read the first physical sector from the boot device. This first disk sector on the boot device contains the master boot record mboot, which is loaded and executed. If no mboot file is found, an error message is displayed.
Reference:
http://docs.sun.com/app/docs/doc/806-4073/6jd67r98d?a=view
When the power to a Macintosh computer is turned on, the BootROM firmware is activated. BootROM (which is part of the computer’s hardware) has two primary responsibilities: it initializes system hardware and it selects an operating system to run. BootROM has two components to help it carry out these functions:
POST (Power-On Self Test) initializes some hardware interfaces and verifies that sufficient memory is available and in a good state.
On PowerPC-based Macintosh computers, Open Firmware initializes the rest of the hardware, builds the initial device tree (a hierarchical representation of devices associated with the computer), and selects the operating system to use.
On Intel-based Macintosh computers, EFI does basic hardware initialization and selects which operating system to use.
If multiple installations of Mac OS X are available, BootROM chooses the one that was last selected by the Startup Disk System Preference. The user can override this choice by holding down the Option key while the computer boots, which causes Open Firmware or EFI to display a screen for choosing the boot volume.
Reference:
http://developer.apple.com/mac/library/documentation/MacOSX/Conceptual/BPSystemStartup/Articles/BootProcess.html
Linux 9 system:
The beginning of the boot process varies depending on the hardware platform being used. However, once the kernel is found and loaded by the boot loader, the default boot process is identical across all architectures. This chapter focuses on the x86 architecture.
Reference:
http://www.redhat.com/docs/manuals/linux/RHL-9-Manual/ref-guide/s1-boot-init-shutdown-process.html#S3-BOOT-INIT-SHUTDOWN-OTHER-ARCHITECTURES
Windows system:
When the system is turned on, the BIOS runs self-test diagnostics to verify the system's hardware and memory. The system begins to boot automatically if no errors are found. If errors are found, error messages are displayed that describe recovery options.
The BIOS of additional hardware devices are run at this time.
The BIOS boot program tries to read the first physical sector from the boot device. This first disk sector on the boot device contains the master boot record mboot, which is loaded and executed. If no mboot file is found, an error message is displayed.
Reference:
http://docs.sun.com/app/docs/doc/806-4073/6jd67r98d?a=view
4.4. The Functions of a Computer Operating System
An operating system is a software component that acts as the core of a computer system. It performs various functions and is essentially the interface that connects your computer and its supported components. In this article, we will discuss the basic functions of the operating system, along with security concerns for the most popular types.
Basic Operation
Drivers play a major role in the operating system. A driver is a program designed to comprehend the functions of a particular device installed on the system. A driver enables the operation of numerous devices, including your mouse, keyboard printer, video card and CD-ROM drive by translating commands from the operating system or the user into commands understood by the associated component. It also translates responses from the component back to the operating system, software application or user.
The operating system performs other functions with system utilities that monitor performance,
debug errors and maintain the system. It also includes a set of libraries often used by applications to perform tasks to enable direct interaction with system components. These common functions run seamlessly and are transparent to most users.
Reference:
http://www.spamlaws.com/operating-system-function.html
Basic Operation
Drivers play a major role in the operating system. A driver is a program designed to comprehend the functions of a particular device installed on the system. A driver enables the operation of numerous devices, including your mouse, keyboard printer, video card and CD-ROM drive by translating commands from the operating system or the user into commands understood by the associated component. It also translates responses from the component back to the operating system, software application or user.
The operating system performs other functions with system utilities that monitor performance,
debug errors and maintain the system. It also includes a set of libraries often used by applications to perform tasks to enable direct interaction with system components. These common functions run seamlessly and are transparent to most users.
Reference:
http://www.spamlaws.com/operating-system-function.html
4.3. The Environment Considerations in the Disposal of Computer Hardware and OH+S considerations in the use of computer equipment.
The IT production industry has a Large Carbon footprint, which can be reduced through the re-use and re-deployment of redundant IT equipment namely Computer Recycling.
Part of the problem computer recycling has is, after upgrading computer systems, most organizations store their old computers, which serve as backup equipment in case newer computers break down. These old computers often sit in storage well beyond their potential useful life. At some point, a decision must be made about disposal of this equipment. Continuing to store it is often not a viable option, it eventually takes up a considerable amount of space. The least desirable option is to throw old computers into the bin. Computer recycling comes to the fore in every scenario possible, not just the effect it has upon the environment, there is also the possibility of someone removing hard drives and recovering sensitive data.
This drives home the point that you should destroy the data on your hard disk - before getting rid of the computer or hard disk in it. Computer recycling, isn't always about the environment, but of company and national safety importance too.
From an environmental point of view it is far better to recycle your computer at an official recycling center than to dispose of it. It may even be illegal in some countries to dispose of electrical equipment by any other method other than by taking it to an approved computer recycling center or sending it back to the original manufacturer.
The fight for the planet is on. It is now fully proven, undeniably, evident that the earth is fighting for its life. During its short but deadly lifespan, human civilization has managed to place a devastating strain on the planet's resources and health.
It is now our duty to reverse this ill effect, even though it may be too late. There are thousands of ways people can contribute to the cause: from taking on older techniques such as recycling paper to utilizing newer technologies like fuel-efficient cars. I'd like to concentrate on one specific way through which people can help the planet- recycling computer equipment.
Reference : Article source: http://ezinearticles.com/?Be-Green---Recycle-Your-Old-Computer-Hardware&id=2138360 , John Pettifer, 2009 EzineArticles.com
A healthy and safe work environment is the right of every worker and employers are charged with the responsibility of ensuring that these standards are met. Occupational Health and Safety or OH&S for short relates to the practices, procedures and tasks that organisations must enforce to comply with legislation and to ensure that they protect the health and welfare of their staff in the workplace.
Computer Ergonomics is concerned with potential and sometimes persistent injuries that can be caused by a person who uses a computer for a large part of their working day. On the scale of human history, the personal computer is a relatively new ‘tool’ that humans have had to get used to using. Computer ergonomics becomes important when you consider fingers moving around keyboards, eyeballs focusing on screens and hands wrapped around mice.
A good workstation setup may include:
Chair / seating
Desk
Monitor / laptop
Mouse
Document solutions
Keyboard
No matter how great your ergonomics workstation is, it's important to take frequent, brief rest breaks. Make sure to practice the following to help avoid strain and injury:
- Eye breaks every 15 minutes.
- Micro-breaks from the use of a particular set of muscles that's doing much of the work (e.g. the finger flexors if you're doing a lot of typing).
- Rest breaks every 30 to 60 minutes.
- Exercise breaks every 1-2 hours.
Reference : Article source: http://ezinearticles.com/?Be-Green---Recycle-Your-Old-Computer-Hardware&id=2138360 , John Pettifer, 2009 EzineArticles.com - All Rights Reserved Worldwide. And http://www.ergonomics-ohs.com.au/
Part of the problem computer recycling has is, after upgrading computer systems, most organizations store their old computers, which serve as backup equipment in case newer computers break down. These old computers often sit in storage well beyond their potential useful life. At some point, a decision must be made about disposal of this equipment. Continuing to store it is often not a viable option, it eventually takes up a considerable amount of space. The least desirable option is to throw old computers into the bin. Computer recycling comes to the fore in every scenario possible, not just the effect it has upon the environment, there is also the possibility of someone removing hard drives and recovering sensitive data.
This drives home the point that you should destroy the data on your hard disk - before getting rid of the computer or hard disk in it. Computer recycling, isn't always about the environment, but of company and national safety importance too.
From an environmental point of view it is far better to recycle your computer at an official recycling center than to dispose of it. It may even be illegal in some countries to dispose of electrical equipment by any other method other than by taking it to an approved computer recycling center or sending it back to the original manufacturer.
The fight for the planet is on. It is now fully proven, undeniably, evident that the earth is fighting for its life. During its short but deadly lifespan, human civilization has managed to place a devastating strain on the planet's resources and health.
It is now our duty to reverse this ill effect, even though it may be too late. There are thousands of ways people can contribute to the cause: from taking on older techniques such as recycling paper to utilizing newer technologies like fuel-efficient cars. I'd like to concentrate on one specific way through which people can help the planet- recycling computer equipment.
Reference : Article source: http://ezinearticles.com/?Be-Green---Recycle-Your-Old-Computer-Hardware&id=2138360 , John Pettifer, 2009 EzineArticles.com
A healthy and safe work environment is the right of every worker and employers are charged with the responsibility of ensuring that these standards are met. Occupational Health and Safety or OH&S for short relates to the practices, procedures and tasks that organisations must enforce to comply with legislation and to ensure that they protect the health and welfare of their staff in the workplace.
Computer Ergonomics is concerned with potential and sometimes persistent injuries that can be caused by a person who uses a computer for a large part of their working day. On the scale of human history, the personal computer is a relatively new ‘tool’ that humans have had to get used to using. Computer ergonomics becomes important when you consider fingers moving around keyboards, eyeballs focusing on screens and hands wrapped around mice.
A good workstation setup may include:
Chair / seating
Desk
Monitor / laptop
Mouse
Document solutions
Keyboard
No matter how great your ergonomics workstation is, it's important to take frequent, brief rest breaks. Make sure to practice the following to help avoid strain and injury:
- Eye breaks every 15 minutes.
- Micro-breaks from the use of a particular set of muscles that's doing much of the work (e.g. the finger flexors if you're doing a lot of typing).
- Rest breaks every 30 to 60 minutes.
- Exercise breaks every 1-2 hours.
Reference : Article source: http://ezinearticles.com/?Be-Green---Recycle-Your-Old-Computer-Hardware&id=2138360 , John Pettifer, 2009 EzineArticles.com - All Rights Reserved Worldwide. And http://www.ergonomics-ohs.com.au/
4.1.7. Internal hardware components, cost, image and function
8. USB/Portable Drives
Western Digital My Passport Essential - Hard drive - 1 TB - external - 2.5" - Hi-Speed USB. the cost is $300.
Western Digital My Passport Essential - Hard drive - 1 TB - external - 2.5" - Hi-Speed USB. the cost is $300.
4.2.7. Internal hardware components, cost, image and function
7. Power Supply
Super silent thermalstatic 14cm blue led Fan
PFC (Power Factor Correction) circuit
Serial ATA ready
Power good signal: 100-500mS
Input Voltage: 230Vac(180-264)/115Vac(90-132)
Input Frequency: 47Hz-63Hz
The cost is $200.
8. USB/Portable Drives
Super silent thermalstatic 14cm blue led Fan
PFC (Power Factor Correction) circuit
Serial ATA ready
Power good signal: 100-500mS
Input Voltage: 230Vac(180-264)/115Vac(90-132)
Input Frequency: 47Hz-63Hz
The cost is $200.
8. USB/Portable Drives
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