Describe How Buses Contribute To A Computer's Processing Speed
Bits are transferred internally within the circuitry of the computer along electrical channels. Each channel, called a bus, allows various devices inside and attached to the system unit to communicate with each other. The bus width, or size of the bus, determines the number of bits that can be transferred at one time. The larger the bus width, the fewer number of transfer steps is required and the faster the transfer of data is. In most computers word size (the number of bits the CPU can process at a given time) is the same as the bus width. Every bus also has a clock speed. The higher the bus clock speed, the faster the transmission of data, which results in applications running faster. A computer has two basic types of buses. Asystem busconnects the CPU to main memory. An expansion busallows the CPU to communicate with peripheral devices.
A highway analogy can help clarify how bus width affects the speed of data transfer. Data moves like cars – the more lanes (greater the bus width) the faster the traffic (data) flow. Ideally, buses used to transfer data should be large enough to use the processing power of registers. Sometimes, however, manufacturers reduce bus size to cut costs.
Word size, which indicates the number of bits processed in each machine cycle, has been compared to the amount of coffee produced with each turn of a coffee grinder’s handle. Theoretically, if word size doubles then processor throughput also could double.
The types of expansion buses on a motherboard determine the types of cards you can add to a computer. Types of expansion buses include:
· An ISA (Industry Standard Architecture) bus, the most common and slowest expansion bus, connects to devices such as a mouse, modem card, sound card, and low-speed network card
· A local bus is a high-speed expansion bus used to connect higher speed devices such as hard disks
· An Accelerated Graphics Port (AGP) is a bus designed by Intel to improve the speed with which 3-D graphics and video transmit
· The universal serial bus (USB) and 1394 bus are buses that eliminate the need to install expansion cards into expansion slots
· A PC Card bus is the expansion bus for a PC Card
Identify Components In A Notebook Computer
Users with mobile computing needs often have a mobile computer, such as a notebook computer and/or handheld computer. A notebook computer, also called a laptop computer, can run either using batteries or using a standard power supply. In addition to the motherboard, processor, memory, sound card, PC Card slot, and drive bay, the system unit for a notebook computer also houses other devices, such as the keyboard, pointing device, speakers, and display.
Identify Components In A Handheld Computer
Handheld computers run strictly on battery. Similar to desktop and notebook computers, handheld computers have a system unit that contains electronic components that process data. A handheld computer’s system unit also contains a display and may house speakers and some form of keyboard and/or pointing device. Handheld computers often have an IrDA port so you can communicate wirelessly.
INPUT
Ex. 1 Pay attention to:
1 flatbed –плоский, планшетного типа
2 bar code scanner – устройство для считывания штриховых кодов
3optical character recognition –оптическое распознавание символов
4 optical mark recognition – оптическое считывание меток
5 magnetic-ink character recognition –распознавание символов, написанных магнитными чернилами
6 UPC – (Universal Product Code) универсальный товарный код
7 visually impaired users – пользователи с нарушениями зрения
Ex. 2 Translate paying attention to the suffixes:
Cord – cordless,wire –wireless –wirelessly.
Ex. 3 Translate paying attention to the prefix:
Misinterpreted, misprinted, misunderstood.
Ex. 4 Translate according to the model:
Model: You input an instruction to the computer by responding… –Вы вводите инструкцию в компьютер, отвечая на …
1.You input an instruction by speaking into microphone.
2.They increase efficiency by reducing the role of the weak link.
3.It improves processing time by storing instructions.
Ex. 5 Translate according to the model:
Model:You use a mouseto movethe pointer. –Вы пользуетесь мышьюдля того, чтобы перемещатькурсор.
1.You use a mouseto performa certain action.
2.Handheld computers provide many different ways to input data.
3.A digital camera is used to take pictures.
4.A digital camera is used to store the photographed images.
5.An optical reader uses light to read codes.
Ex. 6 Translate according to the model:
Model: Many keyboards also have a numeric keypad designed to make … –многие виды клавиатуры также имеют цифровую клавиатуру,предназначенную для того, чтобы …
1.A mouse is a devise designed to fit under your palm.
2.Theyhave keys used to movethe insertion point.
3.It consists of electronic plastic board used to input graphical data.
Ex. 7 Translate paying attention to the parts of speech:
A user response – a computer responses quickly, is used to response; theinput needs – different ways toinput data – you input instructions; it can capture data – video capture; the enhanced revolution – it enhances the efficiency; notebooks are used at – a user’s request – for public use.
Ex. 8 Translate paying attention to the conjunction:
Model:A scannertranslates the results into a form (that) a computer can use. - Сканер переводит результаты в форму, которуюможет использовать компьютер.
1.Every character (that) you type on a keyboard is converted into a corresponding byte.
2.The keyboard contains keys (that) you press to enter data into a computer.
3.A portable keyboard is a full-sized keyboard (that) you can attach to a handheld computer.
4.A user response is an instruction (that) you issue to the computer.
5.An expansion card converts the analog signal into a digital signal (that) the computer can understand.