Archive for the 'Uncategorized' Category

chapter 9 is all about software and how it works , its mainly about security and how safe your internet needs to be , with a password and your very own IP adress for the computer. theres different  sercurity settings for wirless and non-wirelss , for instance with wirelss if someone wanted to join your network you would need to put a password in to acess the network and for non-wirless people can only acess it if your in side the building with the network. there are different viruses that are usesd like worm ,  trojans , TCP/IP attacks most viruses are sent on purpose to computer to computer. if a document has a virus on it and you send it to an another computer it can spread to the computer. there is certain information you need  to make sure you dont get anyone you dont know acsessing your network like dont tell youre own personal password to anyone including your kids,if there is someone asking for your details ask who they are andtell them  what there ID is. and never leave your personal security setting were evryone can see them. there are also some other attacks like these common attacks.

• SYN Flood – Randomly opens TCP ports, tying up the network equipment or computer with a large amount of false requests, causing sessions to be denied to others
• DoS – Sends abnormally large amounts of requests to a system preventing access to the services
• DDoS – Uses “zombies” to make tracing the origin of the DoS attack difficult to locate
• Spoofing – Gains access to resources on devices by pretending to be a trusted computer
• Man-in-the-Middle – Intercepts or inserts false information in traffic between two hosts
• Replay – Uses network sniffers to extract usernames and passwords to be used at a later date to gain access
• DNS Poisoning – Changes the DNS records on a system to point to false servers where the data is recorded

there are also other ways of sercuring  your conputer when stolen to keep your data safe and no one can acess it.

networks & modems- a network interface card is required to connect to the internet. the NIC may come preinstalled or you may have to purchase one on your own. after the NIC  and the driver have been installed , you can connect the computer to the network.

adapter properties in device manager-sometimes a manufactuer will publish new driver software for a NIC. a new driver may enhance the functionaly of the NIC or it may be needed for operating systems compatibility

link lights-now that the NIC drivers are installed you are ready to connect to the network. plug a network cable also called an ethernet patch or straight through cable into the network port on the omputer. plug the other end into the network device or wall jack. after connecting the network cable look at the LED’S or link lights next to the ethernet port on the NIC to see if there is any activity.

 modem- is an electronic device that tranfers data between one computer and another using analog signals over a telephone line.

analog telephone- this technology uses standard voice telephone lines. this type of services uses a modem to place a telephone call to another modem at a remote site , such  as an internet service provider.  there are two major disenvantages og using the phone line with an analog modem.

LAN – communication network that covers a small geographical area and is under the control of a single administrator

WAN – data communicationb network that serves uses across a broad geographic area and often uses transmission devices provided by common carriers frame relay , smds and x.25 are example of WAN .

its cheaper to use network because you pay for the internet all in one and other times you have been sending mail by hand or post you save money all together because you have to pay for postage .

WLAN

PROTOCOL

TCP

OSI

TOPOLOGIES

laser printer- A laser printer are the latest type of printers in technology it last longer than a ordinary ink jet computer because the laser printers use toner what roles 0n the data and last mutch longer for example they can print out 8-200 pieces of paper in 1 minute  and a ink jet printer can do 2-8 pieces of paper in a minute. and also with the ink, you have to keep refilling the cartriges what probally would cost more money than a laser printer all together over the years and with the laser printers you dont have to replace that much. you would use this printer in buisnesses, schools and you could use it at home if you work at home. this works horizantal strips across the page and this is known as a raster line or scan line this is how you image comes out or your piece of data. and the main componenets of the laser printer are toner cartrige , laser scanner , paper transport mechanism , transfer carona , onzone filter. these are the steps that the laser printer uses step 1:cleaning step2:conditioning step3:writing step4:developing step5:transfering step6:fusing and the major dangers ofb the laser cutter that the carona wire or grid , or the conditioning roller can be very dangerous and also the voltage can go as high as -6000 volts

ink jet printer-inkjet printing dates back to the 19th century and the technology was first developed in the early 1950s. this printer can be very reliable but can be very expensive because of the inki cartriges they can cost upto £20-£50. if you print alot your best printer to get is laser printer because it last longer, it can print pages out quicker and dont cost as much. but if you dont print alot stick with a ink jet printer. you would use this printer at home for printing out homework and over pieces of work. for the cartiges there are different colours like red black green yellow brown blue . and more. the componenmets on this computer are parrlel port , control panel , buttons , platen , timing belt , paper feed rolers , printhead position motor , ink cartriges

dot matrix-In 1953, the first high-speed printer was developed by Remington-Rand for use on the Univac.while the first dot matrix printer was marketed by IBM, in 1957, the same year that the dye-sublimation printer entered the market. and also this old printer were worth about £300 and know you see not alot these types of computers so know its worth about £7000. and also this printer , when it prints pages out it comes out a bit blurey and squished together as it aint a accurate printer. you would us ethis in scientific labs and over research places just for giving out data.

thermal- this printer is used for receits so it is a very small printer. it puts data on to the page with selective heat the coating turns black in areas were it is heated producing an image. thermal printers are capable of  printinbg both black and additional colour mostly red by applying heat at a different temperatures.ou would use this printer at shops for giving people receits, so at a cashier. the disavantages are that the paper is expensive , images are poor quality and also the paper must be strored at room temperature.

thermal head-creates heat what prints on paper

platen-a rubber roller what feeds paper

spring-applies pressure to the thermal head

controller boards-for controlling the mechanism

scanners- a scanner is a photo copier and can scan objects to over devices. like if you scan you could only have one piece of work and whem you scan it copies it on the computer and you can change it.