Computer Hardware

The importance of computers in today's world is to simplify tasks and perform complex calculations. They can fit in a wristwatch and are capable of performing billions of operations per second.

The patch panel or patch bay is an instrumental piece of equipment in many offices and technology centres. Fundamentally it houses cable connections and in the majority of cases is rack mounted. The patch panel is typically two sided; the front predominantly houses shorter cable connections whilst the rear has longer wires. This setup is used because it allows the technician to perform temporary alterations to connections at the front while the rear connections remain permanent. This functionality allows for easy and convenient interconnecting, monitoring and circuit testing.

The best tool to verify that hardware components installed in Windows are working properly is the Device Manager. It provides a comprehensive overview of all hardware devices and their status, indicating whether they are functioning correctly or if there are any issues, such as driver problems or conflicts. Users can also access properties for each device to troubleshoot issues or update drivers as needed. Additionally, Windows Performance Monitor can be used for more detailed performance analysis of hardware components.

Very basically your system is based on a CPU (Central Processing Unit) - This controls the other components of the Mother Board . The Mother board holds the DDR DIMM,s (Double Data Rate - Dual Inline Memory Modules / Memory sticks) and the Ethernet controller unit (for Internet) and a fan keeps this cool (30C-55C). There are also additional video cards / etc etc.etc. There are many more components that will be specific to each model of computer, but the above are the basics.

It's a general idea of the "clock" speed that is used by the computer.

The computer clock is not the same kind of clock that we use to tell time, it's simply a signal that tells the processor when to perform the next instruction.

It's sort of like: "Tick, do something. Tick, do something. Tick, do something."

If you're asking about the next prefix, it's peta. Now the actual conversion between terabytes and petabytes depends on what system you're using: The SI standard says that 1024 terabytes would be equal to 1.024 petabytes. The generally used (though technically incorrect) values in computing says that 1024 terabytes would be equal to 1.000 petabytes.

There are currently four different types of bar code readers available. Each uses a slightly different technology for reading and decoding a bar code. There are pen type readers (e.g. bar code wands), laser scanners, CCD readers and camera-based readers. Pen type readers consist of a light source and a photo diode that are placed next to each other in the tip of a pen or wand. To read a bar code, you drag the tip of the pen across all the bars in a steady even motion. The photo diode measures the intensity of the light reflected back from the light source and generates a waveform that is used to measure the widths of the bars and spaces in the bar code. Dark bars in the bar code absorb light and white spaces reflect light so that the voltage waveform generated by the photo diode is an exact duplicate of the bar and space pattern in the bar code. This waveform is decoded by the scanner in a manner similar to the way Morse code dots and dashes are decoded.

Laser scanners work the same way as pen type readers except that they use a laser beam as the light source and typically employ either a reciprocating mirror or a rotating prism to scan the laser beam back and forth across the bar code. Just the same as with the pen type reader, a photo diode is used to measure the intensity of the light reflected back from the bar code. In both pen readers and laser scanners, the light emitted by the reader is tuned to a specific frequency and the photo diode is designed to detect only this same frequency light.

Pen type readers and laser scanners can be purchased with different resolutions to enable them to read bar codes of different sizes. The scanner resolution is measured by the size of the dot of light emitted by the reader. The dot of light should be equal to or slightly smaller than the narrowest element width ("X" dimension). If the dot is wider than the width of the narrowest bar or space, then the dot will overlap two or more bars at a time thereby causing the scanner to not be able to distinguish clear transitions between bars and spaces. If the dot is too small, then any spots or voids in the bars can be misinterpreted as light areas also making a bar code unreadable. The most commonly used X dimension is 13 mils (roughly 4 printer dots on a 300 DPI printer). Because this X dimension is so small, it is extremely important that the bar code is created with a program that creates high resolution graphics (like B-Coder). For a good description of the different graphic file formats that are commonly used to create bar codes see: Raster vs. Vector Graphics CCD (Charge Coupled Device) readers use an array of hundreds of tiny light sensors lined up in a row in the head of the reader. Each sensor can be thought of as a single photo diode that measures the intensity of the light immediately in front of it. Each individual light sensor in the CCD reader is extremely small and because there are hundreds of sensors lined up in a row, a voltage pattern identical to the pattern in a bar code is generated in the reader by sequentially measuring the voltages across each sensor in the row. The important difference between a CCD reader and a pen or laser scanner is that the CCD reader is measuring emitted ambient light from the bar code whereas pen or laser scanners are measuring reflected light of a specific frequency originating from the scanner itself. The fourth and newest type of bar code reader currently available are camera-based readers that use a small video camera to capture an image of a bar code. The reader then uses sophisticated digital image processing techniques to decode the bar code. Video cameras use the same CCD technology as in a CCD bar code reader except that instead of having a single row of sensors, a video camera has hundreds of rows of sensors arranged in a two dimensional array so that they can generate an image. The factors that make a bar code readable are: an adequate print contrast between the light and dark bars and having all bar and space dimensions within the tolerances for the symbology. It is also helpful to have sharp bar edges, few or no spots or voids, a smooth surface and clear margins or "quiet zones" at either end of the printed symbol. All application programs support bar code reading as long as you have the right equipment. Bar code readers are available with two types of output - either "keyboard wedge" output or RS232 output. The bar code readers with keyboard wedge output plug directly into the keyboard port on your PC and they also provide a pigtail connector so that you can plug in your keyboard at the same time. When you scan a bar code with the keyboard wedge bar code reader, the data goes into the computer just as if it were typed in on the keyboard. This makes it extremely easy to interface the bar code reader to any application that is written to accept keyboard data.

The keyboard wedge interface is extremely simple however it has a few drawbacks. If you swipe a bar code, the cursor has to be in the correct input field in the correct application otherwise you end up reading bar code data into whatever application has the focus. This can cause all sorts of potential problems as you can imagine. The keyboard output also is limited in that you cannot modify the data in any way before sending it into the program that is to receive the data. For example, if you needed to parse a bar code message into multiple pieces or remove some of a bar code message or add in a date or time stamp you would not be able to with a normal keyboard wedge reader.

The other possible output option is to get a bar code reader with an RS232 or "Serial" interface. With these types of bar code readers, you connect the reader to an available serial port on the back of your PC. You would then need a program called a "Software Wedge" to take the data from the bar code reader and feed it to the application where you want the data to go. The disadvantage to this approach is that it is a little more complex however you gain much more control over how and where your data ends up when you read a bar code.

Most any device more sophisticated than a simple electronic TV remote probably includes a computer chip or two. Some TV remotes even include them.

Example include: iPods, cell phones, video game consoles, hand-held video game devices.

Others could include larger devices with embedded computers, such as the computer-chip based systems that manage control functions all modern automobiles, such as fuel injection, anti-lock brakes, traction-control technology or air bags.

The Intel Xeon is a CPU used for server systems. Server processors usually need to be bigger and faster than desktop CPUs, because they need to be able to handle a lot more traffic and run constantly.

Lexmark X6570 <---- Does not work! Update: I bought the X6750 ink cartridge and tried to use it in my Dell 948. The cartridges do look identical, but the X6570 (No. 42 or 44) does NOT work in the Dell 948. Don't waste your money. I suspect Dell has rigged the cartridge in some way so that you must buy their ink exclusively for them to make a profit off the ink. This is very common. They sell the printer for $30 bucks and then charge $30 a pop for the ink which is extremely cheap for them to produce. Pure profit. It's a bait and switch game.

Input devices are the hardware that give computers instructions. Output devices relay the response from the computer in the form of a visual response (monitor), sound (speakers) or media devices (CD or DVD drives). The purpose of these devices is to translate the machine's response to a usable form for the computer user.

EEPROM stands for Electrically Erasable Programmable Read-Only Memory. It is non-volatile memory whose bytes can be individually altered, to reprogram the chip, so it is not entirely read-only.

Assuming the question refers to a PC, (or unambiguously) "personal computer", any computer needs some mechanism with which to "get started". The term "bootstrap" or simply "booting" refers to an old phrase "pulling up by the boot straps" and refers to how one, or something; a computer; gets running.

All computers, even early ones, need instructions to basically tell them what to do first. Early computers needed to have a program loaded (via paper cards, or paper tapes, punched with holes representing data which was read into memory and then run as a program which started "everything up") manually by hand.

Modern computers still need something to "start them" but the instructions needed are stored in permanent memory in an integrated circuit, or "chip", in the computer making the process totally automatic.

In more detail:

The instructions used for starting modern computers is typically called the "BIOS" which is an acronym for "Basic Input Output System". It is this program, or "instructions", which first executes when the computer is first powered up. This program does numerous basic tests checking what the hardware looks like, and that its operating correctly.

After the hardware tests, the BIOS then begins to set up basic operating data in main memory (RAM) outlining what hardware is installed in the computer, and how it works, and how to talk to it.

After all this is done, the BIOS then looks for a device to "boot" from, meaning it looks for any device which has the "right look" for it to have the next program to run. Usually, this is the operating system (OS) which then takes control of the computer from that point on.

The BIOS contains numerous simple ways of "talking" to the rest of the computer. However, most modern operating systems (like Linux, Windows, Apple OS, etc.) have better methods of controlling the computer as they have the ability to "figure out" all the details of the computer whereas the BIOS must work no matter what and can thus only reliably provide simple (basic as in BIOS) functions sufficient for the operating system to "get a clue" and then allow it to take total control of the machine.

Once the BIOS does it's testing and basic setup, it then gives up control of the computer to the operating system which then takes over all operations of the computer.

That is the general color for PCBs (printed circuit boards) back then, as the general process for making circuit boards is having a board coated in copper etched in a specific pattern (using a etching chemical to eat away the copper) obtained from the engineer that designed the circuit.

Nowadays computer system boards do not look like the traditional green as manufacturers may shift to slightly different methods of producing their boards.

Both of these forms of communication are a means of transmitting data. The difference is in the format that the data is transmitted.

Asynchronous communications is the method of communications most widely used for PC communication and is commonly used for e-mail applications, Internet access, and asynchronous PC-to-PC communications. Through asynchronous communications, data is transmitted one byte at a time with each byte containing one start bit, eight data bits, and one stop bit, thus yielding a total of ten bits. With asynchronous communications, there is a high amount of overhead because every byte sent contains two extra bits (the start and stop bits) and therefore a substantial loss of performance.

Synchronous communications is the more efficient method of communications. CQ's connectivity solutions communicate through the synchronous method of communications.

Through synchronous communications, data is transmitted as frames of large data blocks rather than bulky individual bytes. One advantage of synchronous is that control information is easily inserted at the beginning and end of each block to ensure constant timing, or synchronization. Another advantage of synchronous is that it is more efficient than asynchronous. For example, a 56 Kbps dial-up synchronous line can carry 7000 bytes per second (56000/8) compared to a 56 Kbps dial-up asynchronous line which can only carry 5600 bytes per second (56000/10). When transmitting large amounts of information, this translates into a significant increase in speed and performance.

To see this work you can work out the efficiency rates and time that it takes to send each message

Asynchronous would be worked out as follows

To get the efficiency of it you

get assuming the message is being send over a 100mb line and 70 bytes to send and 300 characters

then it is

70*8 = 560 (the 8 is for the 8 bits to make up each byte)

the 70*2 (the start and stop bit) =140

= 700

then to

get 560*100/700= 80

that means that 80% efficient

To get the time

Asynchronous

300 *(1+7+1+1) =3000

take this and divide it by the size of the line in this case 100mb

so that is then

3000/100=30

that means that it would take 30 seconds to send

for

synchronous efficiency

Then

70*8= 560

then 4 bytes = 4*8 (the over head bits) = 32

560+32=592

560*100/592=94.5

then that's 94.5% efficient

and for the time then it is just

300+4*8=2342/100=23.42

that's then 23.42 seconds

this shows you which is faster and more efficient in each case

A Keyboard?

How to ruin a computer

What you need: one good baseball bat.

method: pick up the base ball bat and wack the computer hardrive several times. If you turn the computer on and the computer still works repete wacking.

it is so you can tack pictures or video from y our computer

They are unnatural, and therefore unintuitive - the natural way for a human to interact with another human is by verbal and nonverbal communication.

Computer's can't think for themselves. They aren't intelligent. If you feed a computer incorrect information, it will result in an incorrect output.

They cannot adequately deal with 'fuzzy' terms, unlike humans who describe most things in a fuzzy way: "Oh, it was *hot* today," or, "John's car cost him a *fortune*," and "It's *almost* seven o' clock - the takeaway's open."

A computer can't tell you something completely new, it can only derrive something based on something known that it was previously programmed to manipulate. They are not creative or imaginative, nor are they prone to arbitrary moments of genius.

They are unquestioning devices. They do not feel and they do not understand ethics.

Computers can only adequately process information that may be quantised. They cannot adequately deal with abstractions.

Finally, the greatest limitation of a computer is that they are engineered, built and used by humans. They expose our flaws and undersights.

Computers have many capabilities. They are not intelligent machines and work off instructions, therefore it can perform many instructions and complete them almost instantly. Computers can connect to the Internet, which means your computer can share information and resources in real time, thus expanding the capabilties of a computer. Computers are very efficient, fast and also have very accurate results to the things we ask them to do.

firewire port can support up to 63 devices on one firewire port with a hub

(Donna will not work)

Donna, in Mr. Jake's class, is quite docile. she never disrupts class and does little socialising with other students. But despite Mr. Jake's best efforts, Donna rarely completes an assignment. She doesn't seem to care. She is simply there putting forth virtually no effort. How would Kounin deal with Donna? Kounin would suggest to teachers that they use the following sequence of interventions until they find one that is effective with Donna.

1. Use the ripple effect. "I see many people have already completed half their work." look at Donna, later comment, "I'm afraid a few people will have to stay late to complete their work".

The three components that must have the same form factor in a computer are the case, power supply and motherboard. The case should be able to support the form factor of the motherboard and the motherboard should be able to support the CPU socket type.