计算机专业英语(2)(4)

计算机专业英语

random-access memory 随机存取存储器

read-only memory 只读存 储器

start-up 启动 无限期地

blur[blE:] vt.&vi. (使)变模糊 be restricted to 仅限于……，限制在……

sophisticated[sE5fistikeitid] adj.精密的，复杂的

the main memory area. Registers are used for the most frequently needed data items to avoid having to access main memory every time data is needed. As data is constantly being worked on, reducing the need to access main memory greatly increases the computer's speed.

Computer main memory comes in two principal varieties: random-access memory or RAM and read-only memory or ROM. RAM can be read and written to anytime the CPU commands it, but ROM is pre-loaded with data and software that never changes, so the CPU can only read from it. ROM is typically used to store the computer's initial start-up instructions. In general, the contents of RAM are erased when the power to the computer is turned off, distinction between ROM and RAM, as it retains its data when turned off but is also rewritable. It is typically much slower than conventional ROM and RAM however, so its use is restricted to applications where high speed is unnecessary.

In more sophisticated computers there may be one or more RAM cache memories which are slower than registers but faster than main memory. Generally computers with this sort of cache are designed to move frequently needed data into the cache automatically, often without the need for any intervention on the programmer's part.

Input/Output

I/O is the means by which a computer exchanges information with the outside world. Inputs are the signals or data received by the computer, and outputs are the signals or data sent from it. Devices that provide input or output to the computer are called peripherals. Note that the designation of a device as either input or output depends on the perspective. Mouse and keyboards take as input physical movement that the human user outputs and converts it into signals that a computer can understand. The output from these devices is input for the computer. Similarly, printers and monitors take as input signals that a computer outputs. They then convert these signals into representations that human users can see or read. For a human user the process of reading or seeing these representations is receiving input. These interactions between computers and humans are studied in a field called human–computer interaction.

indefinitely[in defEnEtli] adv. but ROM retains its data indefinitely. Flash memory blurs the

peripheral[pE5rifErEl] n. 外围设备，周边设备

perspective[pE5spektiv] n. 远景，透视

monitor[5mCnitE] n. 监视器，显示器

representation[7reprizen5teiFEn] n. 表示，表达

interaction[7intEr5AkFEn] n.交互作用，互动 · 20·