‘H’ is for HARDWARE Unit 3 & 4 IP&M With special acknowledgement of Mark Kelly and the McKinnon site
"I'm In IPM and I Don't Know Anything About What's Inside Computers" Ahhhhhhhh theory again! Talking about the insides of computers. Megawhat? What's a bus doing in a computer? If that kid there mentions floppies again, I'm going to complain to the principal...
2345 6 78910 1112131415 1617181920 2122232425 2627282930 1 Selection one of the following,,,,,,,,,,,,,,,,,,,,,,,,,,10 points for each correct answer………….
1. Information systems are made up of these components: A: people data hardware software procedures
2. Hardware is? A: Hardware is any part of a computer system that you can touch, pick up, drop, or kick.
3. What is a mouse? A: Mouse - the pointing device invented to make GUI (Graphical User Interfaces) possible. The mouse ball drives two rollers, one rolling horizontally, the other vertically. The speed, direction and distance of mouse moves along with any clicks on the buttons is sent to the operating system for interpretation and action. Typical mice (mouses?) with balls suffer from getting gunk on the rollers and must be cleaned occasionally for smooth operation. Some more recent mice do away with the mouse ball and use tiny lasers to read movement under the mouse.
4. What is a pixel? A: Each "dot" on a screen is called a "pixel" (shortened from "picture element".) Each pixel is made up of three coloured dots (one red, one green, one blue). This is where the "RGB" (red/green/blue) stuff come into discussions of video display. By varying the strength of the glow of each coloured dot, a pixel can show an enormous range of colours.
5. Software is? A: Software is invisible - software is programs - but it must be stored on hardware (disks, memory chips, tape etc).
6. What is a hard disk? A hard disk, also called a hard disk drive, consists of several inflexible, circular platters that store items electronically. A magnetic disk stores the 'on' and 'off' bits of binary data as microscopic magnetized needles on the surface of the disk. This data can be recorded and erased any number of times. When computer power is turned off, the data remains stored on the disk. (cont’d next slide)(cont’d next slide) bbbbb
Hard disks: seriously primitive but amazingly reliable and accurate. Using one is like tossing a coin and hoping you get a million heads in a row - but it works! Imagine an aluminium disk about 3.5" (9 cm) in diameter and 2mm thick. Imagine it is on a spindle with maybe 10 or 20 similar disks on the same spindle spinning at 7,200 revolutions per minute (a racing motor bike would be screaming to change gear at that speed). Imagine each disk had a tiny read/write head on a metal stick hovering above its upper and lower surfaces - how high is the head hovering? Considerably lower than the height of human hair or a speck of grease left by a finger print. The only thing keeping the head off the surface of the disk is the few atoms of air holding the head up. Imagine this flying head trying to magnetise a part of the disk, or read the magnetic information already stored on the disk. It has to pack a few million ones and zeros into a few millimetres of disk. It has to do it with 100% accuracy. It's like trying to drop a tennis ball into a bucket from a jet fighter doing 1000 km/h at 10,000 feet. Then you have to circle the fighter and pluck the ball from the bucket 600 times without ever making a mistake. Yet, that's what we expect our hard disks to do every day and swear like sailors when they fail. Personally, I would give hard disk makers medals for magic. The whole concept is mind-boggling, but it's happening even as you read this. Your average hard disk today stores between 10 and 40 GIGABYTES - 320,000 million ones and zeroes. How would you like writing the complete works of Shakespeare a million times on a credit card? More than that, you'd have to read it back perfectly every time you were asked. Amazingly amazing. Most of the time I prefer not to think about how amazing it is that my hard disk works as well as it does. Most of you probably didn't even need to know it was important that you shouldn't think about it. What is important is to back up your data so when the magic of the hard disk inevitably stumbles, you are not surprised. It will fail. At some time, it will fail. It has to. You just need to be prepared when it does: and give thanks that it lasted as long as it did.
7. What is the motherboard? This is the main circuit board of the PC. It contains all the basic, core components of the computer. It usually contains: CPU BIOS chips (Basic Input Output System) Real time Clock (RTC) so the computer knows the time and date. Chips to control basic devices such as hard disks, floppy disks, serial/parallel ports etc.
8. What is a joystick? A: Joysticks are game devices to input movement data. They are easier to use than mice for games such as flight simulators and racing simulators. Yes, they are named after the controls in planes.
9. What is RAM? RAM (Random Access Memory): Chips that store data and programs. RAM loses its memory when power is turned off, which means you will need to save your data and information to a permanent medium (like hard disk) before the power goes off. RAM is rated by its density and speed of retrieval.
10. What does (monitor) resolution mean? A: The amount of detail a monitor can show is called its resolution. The standard minimum resulution nowadays is 800 by 600 pixels. Many people use higher resolution (e.g. 1024 x 768.)
11. What is a trackball? A: Trackballs are like upside down mice: the big ball is rolled with the palm of the hand and the fingers. Since trackballs sit still on the desk, they are handy if space is limited, and the big ball makes precise mouse movement a bit easier.
12. What is a graphics tablet? A: Graphics tablets have a surface like a large touchpad with a pen (stylus) attached. You use the stylus on the tablet to move the mouse pointer. Graphics tablets are commonly used in graphics, art, handwriting input and data plotting. For freehand drawing, a graphics tablet's pen can be much easier to use than a mouse.
13. What is ROM? ROM: Read-Only Memory (and PROM, EPROM, EEPROM, Flash RAM) are different to RAM mainly because they can keep their memory after the power goes off. Once ROM has had its data burned into it, it can never be changed
14. What is the function of the CPU? CPU - Central Processor Unit. The heart of a personal computer (PC). It is the central brain of the whole computer system. In the old days, the CPU was the only processor in a PC. It did everything - and it showed. Nowadays, most 'peripheral' devices have their own processors, and the CPU acts like an office General Manager who delegates work. Rather than trying to do everything, the CPU often sends commands to other devices.
15. What is a USB memory key? USB memory keys (or sometimes called memory sticks) are small devices that plug into a USB port and appear as large removeable disk drives. You can copy files to them as if they were a disk, remove the memory key and carry the data away on your key chain! They are exceptionally useful little beasties. The death of the floppy disk is imminent.
16. What is BIOS? The Basic Input/Output System (BIOS) is a set of program instructions that provide startup information for a computer, and acts as a go-between between an operating system and the hardware in a computer. The BIOS is usually located in flash memory (EEPROM) on the motherboard. When a PC is started, the BIOS runs a power-on self-test (POST). It then tests the system and prepares the computer for operation by searching for other BIOSs on expansion boards (e.g. video card, hard disk controller) and remembering where they are, so the computer can use the plug-in devices later. It then loads the operating system and passes control to it.
17. What is a keyboard? What is the most common type? A keyboard lets you input data into an info system. The most common key layout is called QWERTY (named after the first keys on the top alphabetic row of the keyboard.) QWERTY is a standard, but is very inefficient: it was in fact deliberately designed to slow down fast typists in the early days of mechanical typewriters which tended to jam if the user typed too quickly. The alternative key layout is Dvorak which places the most commonly used keys on the middle "home" row so the typist would not need to move around the keyboard nearly as much. Alas, Dvorak came too late and QWERTY, as horrible as it was, became the standard and still is.
18. Explain the term ‘cache’. Cache is a storage place (buffer or bucket) that exists between two subsystems in order for data to be accessed more quickly to increase performance. Performance is increased because the cache subsystem usually has faster access technology and does not have to cross an additional bus.
19. What is an expansion slot? Expansion slots are sockets that expansion cards like network cards, sound cards, graphics cards can be plugged into. There have been various types of slots over the years to cater for increasingly complex expansion cards. The earliest cards were ISA, then came EISA, then PCI and AGP (which have special high-priority access to the CPU - AGP is used by fast graphic cards). All expansions slots connect to a bus so data can travel between subsystems and the CPU.
20. What is the purpose of the power supply? The power supply provides the electricity needed by the motherboard and different components in the computer. It usually provides a series of power leads carrying 12 volts or 5 volts. A special lead feeds the motherboard and other leads power the disk drives. The power supply is a sealed cube about 12cm on each side and has a fan in it to cool itself down.
21. What is a ‘bit’? A bit is a binary 1 or 0 Binary numbers and arithmetic let you represent any amount you want using just two digits: 0 and 1. Here are some examples: Decimal 1 is binary 0001 Decimal 3 is binary 0011 Decimal 6 is binary 0110 Decimal 9 is binary 1001
22. What are communication ports? Computers need a way to connect to external devices, such as mice, monitors, printers, scanners etc. The sockets on the back (and front) of computers are called ports and are designed to allow peripheral (external) devices to be attached to a system to enhance its abilities. There are several different types of ports.
23. What is a touchpad? A: Touch pads are common on laptop computers. A little smaller than a credit card, they respond to finger touches. Dragging a finger across the pad is like moving the mouse. Tapping the touchpad acts like the mouse buttons. They are surprisingly accurate and intuitive to use and they are virtually indestructible.
24. What is a computer network? Computer networks are no more than computers that are linked together so they can communicate. Network size is in describing a network: there are local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). When WANs get interconnected, you have the Internet.
25. What is a NIC? To connect a computer to a network, you need a network interface card (NIC) in it. This is what the network cable gets plugged in to. Computers can be linked together with cables or the connection can be wireless (through radio communication).
26. What is a device driver? Device drivers are the go-between: a "handler" that accepted generic commands from the operating system and translated the generic command into the specific language spoken by the device. This handler is a small program, and is known as a driver: all hardware devices need drivers (which is why you nearly always get a disk with each hardware gadget you buy; the driver for the device is on the disk.) Devices such as printers, modems, scanners, video cards all do their work in their own way; they have their own set of commands they understand. However, regardless of how they work internally, they must all connect to the same operating system and work properly. The commands sent from the operating system to the driver are "universal" commands: the OS does not care what language the printer speaks. It just tells the driver what it wants.
27. What is the purpose of switches and hubs? Networks need to connect cables together. They use switches and hubs to do this. A hub is a device that lets a single network cable to split into multiple cables leading to nodes (network devices such as computers, printers, other hubs). Hubs and switches do essentially the same job. A PC's network card is connected by cable to a hub or switch. The hub/switch is in turn connected to the file server. Switches are rather more intelligent and efficient than hubs and reduce the amount of network traffic. When the file server transmits a message to a PC via a hub, the hub sends the message to every PC connected to it. A switch, however, knows which PC the message is meant for and directs the message just to that PC. The other PCs on the network aren't flooded with irrelevant traffic.
28. Complete the following: ? - Bits in a byte ? - Bytes in a Kilobyte ? - Kilobytes in a Megabyte 8 1024 bytes 1024
29. What is a protocol? The rules used by the network for sending data is called a protocol. Protocols are to computers what language is to humans. For two devices on a network to successfully communicate, they must both understand the same protocols. TCP/IP A combination of two packet-switching protocols (Transport Communications Protocol and Internet Protocol) that forms the basis of all Internet communications. TCP is the protocol used to break messages into packets in the sending computer, and also to reassemble them in the destination computer.
30 What is a printer? Name more than one type of printer. printers - they, well, print. They are an output device. There are four main types of printer: 1. laser: expensive to buy, cheap to run, fast, high resolution, quiet(ish), page based 2. inkjet: cheap to buy, expensive to run, slow, medium to high resolution, quiet, pixel based. 3. dot matrix: medium expense to buy, medium expense to run, LOUD, low resolution, line-based. 4. thermal - cheap to buy, expensive to run (paper cost), medium speed, low resolution, silent, character-based.