Clip 1 Summary:
There are three types of ports, serial, parallel, and game ports, and they have for the most part been replaced with USB ports. USB devices are hot swappable, can daisy chain, and 127 devices may be plugged into the computer USB ports. Modern mice and keyboards use PS/2 technology unlike older predated mice and keyboards, which used serial connectors, and a 5-pin bulky din connector. The network interface card is responsible for connecting your computer to your local network, a distant network, or to the internet. The dial-up modem is the slowest possible method of connecting to the internet, and it connects to the phone line; the standard speed for a modem is 56Kbps.
Modern computers come with two types of video ports VGA and DVI, in addition may also have an S-Video port you may connect to the TV. SCSI connectors come with a variety of sizes, but the most common are the 50 pin connector for the A-type narrow SCSI cable, and the 68-pin connector for the p-type wide SCSI cable. IEEE 1394 also known as fire wire uses serial communication, it is very fast, hot swappable, and is especially useful when transmitting streaming media. Multimedia devices such as microphones, earphones, and speakers are usually located at the back of the CPU, but in some cases there is a second set on the front of the computer as well.
Clip 2 Summary: There are two types of computer monitors on the market today, the older CRT monitors, which are big and bulky and the newer LCD monitors which take up less desk space.CRT monitors use cathode ray tubes and LCD monitors use a technology called TET also referred to as active matrix. Refresh rate and response time are both terms used to refer to the amount of time it takes to create a new image on the screen. CRT monitors supports many resolutions but an LCD monitor is designed to support a fixed resolution called native resolution. Clip 2 also describes how to configure the resolution settings, and how to configure dual monitors.
Most modern monitors are able to receive both analog and digital signals, and modern video cards are designed to run in either a special high speed video slot called AGP or in the newer even faster PCI Express slot. If you are experiencing a wavy image or a flicker in the image on the screen you may be experiencing a problem with EMI. Never open a CRT monitor case, and never try to take the monitor apart not even an old broken monitor. Reason for this is because there is a stored electrical charge, and if touched accidentally you could possibly die.
Clip 3 Summary: There are three basic types of printers’ dot matrix, inkjet and laser. Dot matrix printers are impact printers; they use clusters of pins striking an inked ribbon to form letters. There are two types of inkjet printers, thermal bubble, and piezoelectric, inkjet printers require a special kid of paper with waxed coding which keeps the ink from smearing. There are six steps in laser printing, the first step is cleaning the sweeping blade, the second is conditioning, the third is writing, the fourth is developing, the fifth is transferring, and the sixth is fusing. Clip 3 also describes the types of problems you are faced with laser printers; printer interfaces are associated with connecting the printer to the computer or to a network, traditional connectors use a 36 pin centronics connector at the printer, and a 25 pin parallel connector at the computer. When installing a printer you must run the operating disk first then connect the printer to the computer.
There are three ways to improve printing performance, adding more memory, moving or deleting graphics, and lowering the resolution. Spooling sends the print job to the print queue which stores the print job in memory, freeing the operating system for other activities. A queue is a list of print jobs waiting to be printed, and you can access the queue by double clicking the printer icon.
Topics:
* Ports and connectors * Serial, parallel, game ports * Mouse and Keyboard * NIC * Modem * Video * USB * SCSI * IEEE 1394 * Multimedia * Video * Monitors * Specifications * CRT resolution * LCD resolution * Connectors * Video Buses * Troubleshooting * Warning * Printers and hardware * Types of printers * Dot Matrix * Inkjet * Six steps in laser printing * Problems with laser printing * Printer interfaces * Installing a printer * Improving performance * Spooling
Terms:
* Serial ports- A connector on a computer to which you can attach a serial line connected to peripherals which communicate using a serial (bit-stream) protocol. * Game ports- An early I/O connector that is used to attach a joystick or other video game controller. * Parallel ports- a socket that can be used for connecting devices that send and receive data at more than one bit at a time; often used for connecting printers. * NIC- an expansion board you insert into a computer so the computer can be connected to a network. Most NICs are designed for a particular type of network, protocol, and media, although some can serve multiple networks. * Modem- is a device or program that enables a computer to transmit data over, for example, telephone or cable lines. * VGA- A graphics display system for PCs developed by IBM. * DVI- Short for Digital Visual Interface, a digital interface standard created by the Digital Display Working Group (DDWG) to convert analog signals into digital signals to accommodate both analog and digital monitors. * USB- Short for Universal Serial Bus, an external bus standard that supports data transfer rates of 12 Mbps. * USB2- Also referred to as Hi-Speed USB, USB 2.0 is an external bus that supports data rates up to 480Mbps. * SCSI- the Small Computer System Interface (SCSI) is a set of parallel interface standards developed by the American National Standards Institute (ANSI) for attaching printers, disk drives, scanners and other peripherals to computers. * IEEE 1394- A very fast external bus standard that supports data transfer rates of up to 400Mbps (in 1394a) and 800Mbps (in 1394b). * CRT- The technology used in most televisions and computer display screens. A CRT works by moving an electron beam back and forth across the back of the screen. * LCD- A type of display used in digital watches and many portable computers that uses two sheets of polarizing material with a liquid crystal solution between them. * TET (Active Matrix)- Short for thin film transistor, a type of LCD flat-panel display screen, in which each pixel is controlled by from one to four transistors. The TFT technology provides the best resolution of all the flat-panel techniques, but it is also the most expensive. * Screen size- is the physical size of the area where pictures and videos are displayed. The size of a screen is usually described by the length of its diagonal, which is the distance between opposite corners. * Contrast ratio- In reference to computer monitors, the measurement of the difference in light intensity between the brightest white and the darkest black. * Refresh rate- the number of times each second that the CRT’s electronic beam writes to the screen and refreshes the image. * Response time- the amount of time it takes the LCD to create a new screen * Interlacing- describes a situation in which the electronic beam in a CRT monitor writes alternating lines during each refresh cycle, this technique is used to help compensate for a slower refresh rate. * Dot pitch- is the distance between the phosphorescent dots that form the image on the screen. * Pixel pitch- the number of addressable pixels on the screen, pixel pitch is the same as the resolution on an LCD monitor. * Resolution- the number of points on the screen that can be addressed by the monitor. * Native resolution- a fixed resolution that is designed for an LCD monitor. * AGP- a special high speed video slot * PCI express- a newer even faster PCI slot that is roughly twice as fast as AGP. * Dot matrix- impact printer that’s uses clusters of pins striking on inked ribbons to form letters, and symbols on the page like a type writer. * Inkjet- a type of printer that works by spraying ionized ink at a waxed sheet of paper. Magnetized plates in the ink's path direct the ink onto the paper in the desired shapes. * Laser- a type of printer that utilizes a laser beam to produce an image on a drum. The light of the laser alters the electrical charge on the drum wherever it hits. * Thermal bubble- a printer that uses heat to transfer an impression onto paper. * Piezoelectric- this technology, patented by Epson, uses piezo crystals that are located behind each nozzle's ink reservoir. The crystals are made to vibrate with static electricity. When they vibrate inward, ink is forced out of a nozzle. When the crystals vibrate outward, they pull ink into a nozzle's reservoir to replace the ink that was sprayed out. * CYMB- a four color system that stands for cyan, yellow, magenta, and black * Cleaning- the first step in the six steps of the laser printing process, a sweeping blade cleans left over toner from the drum and an erase slamp leaves the drum with a neutral charge. * Conditioning- this process places a negative 600 volt charge on the drum. * Writing- during this phase a laser transfers the images to be printed onto the drum, each place the laser strikes reduces the drums charge from a negative 600 volts to a negative 100 volts, now the image has a more positive charge then the rest of the drum. * Developing- toner contains iron fillings that have been given a charge in between that of the drum and the image, because like charges repel and opposite charges attract the toner and is repelled by the drum and attracted to the image. * Transferring- A transfer corona transfers a 600 volt positive charge to the paper, the positive charge attracts the same toner from the image area of the drum and places it on the paper. * Fusing- the fusing rollers heat the toner, melt it, and press it into the paper. * Printer Interfaces- associated with connecting the printer to a network. * Spooling- sends the print job to the print queue stores the print job in memory, trees the operating system for other activities. * Queue- a list of print jobs waiting to be printed you can access the queue by double clicking the printer icon.
Summary of thoughts: I found that these video clips were very informative; they contained a lot of material on relative topics in class. A few things I learned was how to configure resolution settings, I also learned how to configure dual monitors. Another thing I learned was how to install a printer; I didn’t really find anything confusing everything was explained very well so that I could understand it. Where I might use the information is in anything involved with networking, or something involving programming.