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

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

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/

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.

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

4.2.6. Internal hardware components, cost, image and function

6. Cd/DVD/ Blu-ray Drive



Supports most BD, DVD & CD formats
• Cyberlink BD Suite Software featuring full support for Blu-ray playback & DVD/CD authoring
• BD-R 8x, BD-RE 6x, BD-RE DL 4x, BD-ROM 8x, BD-ROM DL 4x
• DVD+R 16x/16x, DVD-R 16x/16x, DVD-ROM 16x, DVD+RW 12x/8x, DVD-RW 12x/6x, DVD-RAM 12x/12x
• CD 48x, CD-R 40x/48x, CD-RW 40x/32x • Also supports DVD-Video, Video-CD, Photo CD, CD-ROM/XA, CD-TEXT, CD-Audio, CD-I(FMV), CD-Extra
• Speed Adjustment Technology (S.A.T), Magic Speed, Double O.P.C Technology, Firmware Live Update, Tilt Actuator Compensation Technology (TAC), Buffer Under Run Technology
• Samsung ECO Product
The cost is $125.

7. Power Supply
8. USB/Portable Drives

4.2.5. Internal hardware components, cost, image and function

5. Graphic Card




GeForce® GTX 480 (1536MB GDDR5)

Give your gamers an adrenaline shot with the fastest GPU on the planet. Experience heart-pounding, cinematic visuals in stereoscopic 3D with the combined power of DirectX11, NVIDIA PhysX and NVIDIA 3D Vision Surround technologies. GeForce® GTX480: pure adrenaline meets visual bliss. The cost is $750.

6. Cd/DVD/Blu-ray Drive
7. Power Supply
8. USB/Portable Drives

4.2.4. Internal hardware components, cost, image and function

4. Fan



Optimally designed aluminum fins disperse heat from the CPU via 5 heatpipes. while the capacity 120mm fan quickly cools the heatsink for stable operation of high performance CPUs. The cost is $90.

5. Graphic Card
6. Cd/DVD/Blu-ray Drive
7. Power Supply
8. USB/Portable Drives

4.2.3. Internal hardware components, cost, image and function

3. Motherboard



AMD Athlon 64 X2 / Athlon 64 35W/65W Mini-ITX Motherboard
Features
Designed for Mini-ITX Motherboard
Supports Socket AM2 AMD Athlon 64/Athlon 64 X2 35W/65W CPU
Integrated AMD M690G + SB600 Chipset
Integrated AMD HyperTransport Technology
System memory up to 4GB DDR2 800 SDRAM
Integrated VGA / LVDS / DVI, ATI Graphic Integrate X700
Dual Gigabit LAN
High Performance and Anti-Vibration to ensure maximum reliability
2 x SATAII, 10 x USB 2.0, 4 x COM, 2 x RJ-45
1 x Mini PCI, 1 x PCI, 1 x VGA, 1 x DVI
The cost is $200.

4. Fan
5. Graphic Card
6. Cd/DVD/Blu-ray Drive
7. Power Supply
8. USB/Portable Drives