Wednesday, October 27, 2010

A Description of the different PC and Macintosh Operating Systems

PC stands for Personal Computer and refers to any IBM-compatible computer. The term PC comes from the first personal computer made by IBM. A computer that is IBM-compatible means that its architecture is based on the IBM microprocessor. A number of different operating systems are compatible with PCs, the most popular of which is Microsoft Windows. Some others are the unix variants, such as Linux, FreeBSD and Solaris.
Mac is short for Macintosh and refers to any computer produced by Apple Computer. Macs are traditionally classified separately from PCs because they are based on the PowerPC architecture from Apple/IBM/Motorola instead of the traditional Intel based microprocessors that have powered PCs for decades. A great deal of software is also compatible with either Mac or PC, but not both.
As time moves on the line between Mac and PC as begun to blur. Apple redesigned their operating system based on UNIX in 2000, and more software packages and file formats have become interoperable between PCs and Macs every day. In early 2006, Apple switched to an Intel architecture for their computer systems which now makes it possible to run Microsoft Windows on Mac hardware. Up until this point Apple hardware only support the Macintosh Operating System (Mac OS), and Mac OS itself was not compatible with any other hardware besides Apple’s.
PCs and Macs are still not 100% compatible, despite their now similar architectures. While many software vendors release their products for both platforms, not all do. Particularly, most of the popular computer games are PC-only.

The Relationship between an Application program, the operating system and hardware

All three (Application program, the operating system and hardware) are needed to accomplish a purpose --
hardware to house components, an operating system to run the components, and an application to be run.

An operating system is defined as an application which is run on a computer. Some common examples of operating systems are Windows, Macintosh, Microsoft Disc Operating System (which is abbreviated as MS-DOS), Linux, etc. On the other hand, an application software program is a class of computer applications that enables the user to perform a required task by using the full capabilities of his or her personal computer directly. System software applications are those applications that play a direct role in integrating the various capabilities of a computer. However, a system software program does not usually apply the capabilities of a computer directly to the performance of the task at hand. In that sense, it can be said to be in direct contrast to an application software program.

An operating system can also be defined as the platform on which a personal computer is run. In the absence of an operating system, the computer would only display a typed code, which is not easy to comprehend. Some common examples of application software programs are word processors, spreadsheets and media players. Operating systems directly communicate with the hardware.

A Description of the Boot Process

In order for a computer to successfully boot, its BIOS, operating system and hardware components must all be working properly; failure of any one of these three elements will likely result in a failed boot sequence.
When the computer's power is first turned on, the CPU initializes itself, which is triggered by a series of clock ticks generated by the system clock. Part of the CPU's initialization is to look to the system's ROM BIOS for its 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 keyboard and mouse, to ensure they are functioning properly.
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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.
The BIOS typically looks to the CMOS chip to tell it where to find the OS, and in most PCs, the OS loads from the C drive on the hard drive even though the BIOS has the capability to load the OS from a floppy disk, CD or ZIP drive. The order of drives that the CMOS looks to in order to locate the OS is called the boot sequence, which can be changed by altering the CMOS setup. Looking to the appropriate boot drive, the BIOS will first encounter the boot record, which tells it where to find the beginning of the OS and the subsequent program file that will initialize the OS.
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 (which the BIOS already checked) and loads the device drivers that it needs to control the peripheral devices, such as a printer, scanner, optical drive, mouse and keyboard. This is the final stage in the boot process, after which 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 your computer. It performs many functions and is, in very basic terms, an interface between your computer and the outside world. In the section about hardware, a computer is described as consisting of several component parts including your monitor, keyboard, mouse, and other parts. The operating system provides an interface to these parts using what is referred to as "drivers". This is why sometimes when you install a new printer or other piece of hardware, your system will ask you to install more software called a driver.

The operating system provides for several other functions including:
  • System tools (programs) used to monitor computer performance, debug problems, or maintain parts of the system.
  • A set of libraries or functions which programs may use to perform specific tasks especially relating to interfacing with computer system components.
The operating system makes these interfacing functions along with its other functions operate smoothly and these functions are mostly transparent to the user.

The Environment Considerations in the Disposal of Computer Hardware and OH+S considerations in the use of computer equipment.

The Environmental Impacts of Computer Disposal


As computers become more ubiquitous it becomes more apparent that these computers will continue to generate a significant amount of problems related to their disposal. As modern operating systems and software require more horsepower the need for users to replace their computers will increase which only increases the amount of waste computers. There are several ways in order to keep these old computers out of the waste stream and ways to safely handle the computers after they have entered the waste stream. Another problem is with the computers that find their way to the dump, without passing through a method to reuse or recycle them, is the lead used in the solder. Lead has been used for years in consumer electronics and now people are looking for alternatives.
One major aspect of waste computers that needs to be strongly looked into is the reuse of computers. The vast majority of computers reach their end of life fully operational, baring small problems like virus infections and part damage. The easiest way to reuse the computer is to give it to someone else who may not need as new of a computer. Most companies purchase computers in large blocks but the machines that are replaced can replace other older computers[1]. This allows the computer to be used for a few years longer than it would have normally. Another way in which these computers see more use is by placing them in “schools, non-profits, and charities”[3]. Because computers are very modular devices and units can easily be swapped out in order to upgrade the computer[1]. The computer can be easily broken down into the casing, motherboard, memory, power supply, hard drive, and CD-ROM drive which can either be replace, if they are broken, or used in a different computer[1].
Eventually a computer will reach a point where it can no longer be used due to age or damage and will need to be recycled. The simplest method is to just shred the computer which can recover up to 400 g of precious metals found in the components[1]. This allows for all part of the computer to be treated as the same and because of this the labor costs are very lower[1]. The other option is the complete remanufacturer of the computer but this option has a very high labor cost associated with it[1]. Neither of this options are idea because remanufacturing a computer is not usually desirable due to the rapid development of computer technologies and shredding a computer destroys any portion of the computer that may be usable[1]. Another problem is that comparison to other “post-consumer products (i.e. Glass bottles, steal cans, scrap cars, etc.)”[2] the waste generated by computers is so new that recycling companies are not prepared to handle it[2]. So much so that the EPA of Taiwan proposed “Scrap Computer Treatment Guidelines” for recyclers interested in processing computers[2]. There are several parts of a computer that are considered hazardous and toxic by many governments on earth including the phosphor coatings of cathode ray tubes (CRTs), batteries, capacitors, LCDs, and the plastic containing flame-retardant bromine[2]. The fear is that the chemical that can leach out of these parts will find their way into the drinking supply near the dump where they were disposed of [2].
One of the major environmental impacts of dumping computers into landfills is due to the fact that the solder used in the components of the circuit boards is comprised of a tin-lead alloy and over time the lead can leach from the solder. Usually the lead, which is a toxic substance, finds it’s way into the drinking water[4]. In fact, it has been speculated by some historians that the fall of the Roman Empire could have been due to the lead used in the citie’s drinking water pipes[5]. In order to combat this the industry is trying to move away from lead based solder with limited success. Because tin-lead solder has been used for a very long time it has been difficult to find a replacement[4] and there are several criteria that they are judging replacements with including (but not limited to): a melting point similar to Tin-Lead solder, good fatigue resistance, relatively non-toxic, and cost[4]. Much work has gone into replacing the lead in conventional solder with with other elements with limited success. The main problem is that lead is relatively cheap when compared to other elements because of it’s abundance in the Earth’s Crust and potential replacements are usually at least twice as expensive[5]. One problem is that tin-lead solders have a low melting point and potential replacements have a higher melting point which increases the thermal stress that is put on electronic parts[6].
There are several possible solutions to replacing lead based solder. One possibility is using just tin for solder. Currently, tin is mostly used by the electronics industry and by using only tin the consumption of tin increases from 60,000 tonnes per year to 80,000 tonnes per year[4]. This may seem like a large increase but it still within the amount of excess tin mined every year[4]. The viability of tin as a replacement is so good that Sandia National Lab considers 100Sn solder to be a valid replacement for current tin-lead solders[4]. Another possibility is replacing the solder completely by using new techniques to make electrical interconnections. One possibility is using electrically conductive adhesive materials[6]. The idea behind electrically conductive adhesive materials is to use an adhesive to attach the circuit elements to the circuit board[6]. In many situations these adhesives work just as well as solder except in situations where there is very high current or in areas of high humidity[6].
A major issue that needs to looked at seriously is the fact that replacements for tin-lead solder may also pose potential problems. A study found that tin-silver-copper, tin-silver, tin-copper, and tin-antimony solders all leached chemicals[5]. Due to the low solubility of tin salt in water tin did not leach significantly[5]. Because silver and antimony are both likely to be used in any tin-lead solder this may cause problems in the future for lead-free solders[5].
The effects of electronics on the environment need to be full realizes as these devices become garbage faster and faster. Computers can be reused where normally they would be thrown out. This will help radically with the amount of waste that is generated due to these devices. Non-toxic methods of construction also need to looked into which will keep people from becoming sick.


Reference : Article source: http://www.scottwarren.info/2008/05/22/the-environmental-impacts-of-computer-disposal/  , Scott Warren, 2008 - All Rights Reserved Worldwide. 

Computer Recycling

Important Changes to the Computer Recycling Program!!

In addition to our convenient process to dispose of old and unneeded computer monitors and CPUs, Environmental Health and Safety has added a service that includes data destruction of the contents of the hard drive. We are using a process that follows US Department of Defense procedures for this work.
Recently, we have noticed that computers with potentially sensitive data may have been left unsecured while awaiting pick-up by our recycling contractor. Also, computers that were given away or otherwise disposed of without the hard drives being “wiped” are causes for concern. Our new procedure can prevent future access to the restricted data that may be contained on our “unwanted” computers.

The following statement comes from the University’s Director of Information Security:

·                                 “No computer containing unencrypted “personal information” covered under the Pennsylvania Breach of Personal Information Notification Act shall ever be placed in a physical (or logical) location where the hard disks may be accessed by an unauthorized person. This includes computers waiting for recycling pick-up.
·                                 “Personal information” is defined as an individual’s first name (or first initial) and last name linked with one or more of the following data elements: (1) their Social Security number (2) their driver’s license number, or (3) their financial account number or credit or debit card number in combination with any required access code or password.
·                                 Any concerns about a possible breach of “personal information” must be reported immediately to the Information Security Office (iso@andrew.cmu.edu).”
Rising costs for this program have necessitated changes to the list of computer-related items the University will accept for recycling. These items will be limited to materials that are either mandated for recycling for because of hazardous material content or that must be recycled by our program to address data security issues.

The following items MUST continue to be recycled by ALL of our University community:

·                                 All cathode ray tube (CRT) monitors.
·                                 All CPUs or any related item that has electronic data or information stored on/in it.
The data will be destroyed by our recycling contractor according to University specifications designed to prevent data from being recovered by unauthorized persons. Do not attempt to destroy any data yourself—it is unnecessary for you to do so and may adversely affect the value of the items as recycled product.
Remember that the items for recycling must remain physically and logically secured awaiting pick-up. Items with hard drives still present must NOT be left in hallways or otherwise where they may be scavenged.






Internal hardware components, cost, image and function

Intel Core i7-860 2.8GHz LGA 1156 95W Quad-Core ProcessorThe Processor

Intel Core i7-860 2.8GHz
279.99


The processor (CPU, for Central Processing Unit) is the computer's brain. It allows the processing of numeric data, meaning information entered in binary form, and the execution of instructions stored in memory. 


Gigabyte Intel Core i7/i5/LGA1156/4DDR3-2200/CrossFireX/SLI/2GBE/Raid/SATA3/eSATA/USB3.0/7.1-CH/1394 ATX Motherboard GA-P55A-UD4PThe Motherboard

Gigabyte GA-P55A-UD4P

$184.99

The motherboard is the main circuit board inside your PC for Every component at some point to communicate through the motherboard, either by directly plugging into it or by communicating through one of the motherboards ports.


Ballistix 240-pin DDR3 DIMMRAM
Crucial Ballistix 2GB PC3-12800 DDR3

$57.99

The Ram is used for the following purposes:
• Storage of a copy of the main systems program that controls the general operation of the computer. This copy is loaded into RAM when the computer is turn on; it stays there as long as the computer is on.
• Temporary storage of a copy of application program instructions to be retrieved by the central processing unit (CPU) for interpretation and execution.
• Temporary storage of data that has been input from the keyboard or other input device until instructions call for the data to be transferred into the CPU for processing.
• Temporary storage of data that has been produced as a result of processing until instructions call for the data to be used again in subsequent processing or to be transferred to an output device such as the screen, a printer, or a disk storage device.

EVGA GeForce GTX 260 Core 216 896-P3-1255-AR Video CardVideo Card

EVGA GeForce GTX 260 Core 216 896MB DDR3
199.99

A video card, video adapter, graphics accelerator card, display adapter, or graphics card is an expansion card whose function is to generate output images to a display. Many video cards offer added functions, such as accelerated rendering of 3D scenes and 2D graphics, video capture, TV-tuner adapter, MPEG-2/MPEG-4 decoding, FireWire, light pen, TV output, or the ability to connect multiple monitors (multi-monitor).


Creative Sound Blaster X-Fi XtremeGamer Sound Card (70SB073A00000)Sound Card

Sound Blaster X-Fi XtremeGamer Sound Card
$84.99

The sound card's four main functions are: as a synthesizer (generating sounds), as a MIDI interface, analog-to-digital conversion (used, for example, in recording sound from a microphone), and digital-to-analog conversion(used, for example, to reproduce sound for a speaker).

What Are the Functions of Hard Drives?Hard Drive

Western Digital Caviar SE16 640GB 7200rpm SATA 300 MB/s
$69.99
Besides storing digital information, hard disk drives also contain all of a computer's operating data, including the operating system. In configurations with multiple hard drives, they are also useful in backing up data for archival purposes.


CD-RW and DVD RW

Sony 24x SATA DVD RW/CDRW (Black)
$19.99

CD-RW drives have three different functions: to read CDs, write CDs and read DVDs. This includes CD-ROMs as well as DVD-ROMs. These drives are perfect for installing programs from CD-ROMs, listening to audio CDs, burning audio and data CDs, and watching DVDs.







External hardware components and peripherals, cost, image and function






Logitech Cordless Desktop EX100
 Logitech Cordless Desktop EX100

Logitech Cordless Desktop EX100
$29.99

Keyboard: This is where the user enters text commands into the computer
Mouse - A point and click interface for entering commands which works well in graphical environments.


 Product Details

ASUS VK246H 24-Inch Widescreen LCD Monitor with Webcam

$220.30

This device operates like a TV set lets the user see how the computer is responding to their commands.

 Product Details
Logitech S220 2.1 Speaker System with Subwoofer
$27.99
The computer speaker is an output device which gives the user auditory feedback regarding the state of the computer.


Product Details

Lexmark Prospect Pro205 Wireless Multifunction Inkjet Printer
$117.54
a printer is a peripheral which produces a text and/or graphics) of documents
A scanner is used to input paper documents or photos into the computer.


Product Details

NETGEAR DGN2000 Wireless-N Router with Built-in DSL Modem
$54.95
The function of a modem is Modulation And Demodulation mean to turn data into a format that can be transmitted via an audio link such as a phone line