计算机专业英语教程第5版翻译 绝对准确

光盘上所需要的位置，所以不需要存取臂。

Optical laser disks are becoming a very inviting option for users. They are less sensitive to environmental fluctuations, and they provide more direct-access storage at a cost that is much less per megabyte of storage than the magnetic-disk alternative. Optical laser disk technology is still emerging and has yet to stabilize; however, at present there are three main categories of optical laser disks. They are CD-ROM, recordable CD-R and rewritable CD-RW, and magneto-optical disk.

对用户而言，光盘正成为最有吸引力的选择。它们(光盘)对环境变化不太敏感，并且它们以每兆字节比磁盘低得多的存储器价格提供更多的直接存取存储器。光盘技术仍在出现，并且还需要稳定；然而，目前有三种主要类型的光盘。它们是CD-ROM、WORM盘和磁光盘。

CD-ROM

Introduced in 1980, the extraordinarily successful CD, or compact disk, is an optical laser disk designed to enhance the recorded reproduction of music. To make a CD recording, the analog sounds of music are translated into their digital equivalents and stored on a 4.72-inch optical laser disk. Seventy-four minutes of music can be recorded on each disk in digital format by 2 billion digital bits. With its tremendous storage capacity, computer-industry entrepreneurs immediately recognized the potential of optical laser disk technology. In effect, anything that can be digitized can be stored on optical laser disk: data, text, voice, still pictures, music, graphics, and video.

1980年引入的，非常成功的CD，或紧密盘是设计来提高音乐的录音重放质量的光盘。为了制作一张CD，把音乐的模拟声音转换成等价的数字声音，并且存储在一张4.72英寸的光盘上。在每张光盘上可以用数字格式（用20亿数字位）记录74分钟的音乐。因为它的巨大存储容量，计算机工业的企业家们立刻认识到光盘技术的潜力。事实上，任何可以被数字化的东西都能存储在光盘上：数据、正文、声音、静止图象、音乐、图形和视频。

CD-ROM(pronounced cee-dee-ROM) is a spinoff of audio CD technology. CD-ROM stand for compact disk-read only memory. The name implies its application. CD-ROM disks, like long-playing record albums, are “pressed” at the factory and distributed with their prerecorded contents(for example, the complete works of Shakespeare or the first 30 minutes of Gone with the wind). Once inserted into the disk drive, the text, video images, and so on can be read into primary storage for processing or display; however, the data on the disk are fixed—they cannot be altered. This is in contrast, of course, to the read/write capability of magnetic disks.

CD-ROM（读作C—D—ROM）是音频CD技术的副产品。CD-ROM代表紧密盘—只读存储器。该名字隐含了它的应用。只读光盘与 (能长期播放的) 唱片一样，在工厂里“压制”并带着预先录好的内容 (如莎士比亚全集，或电影“飘”的前30分钟部分)，分发出去。一旦光盘插入光盘驱动器，正文、视频图像等等就能读入主存进行处理或显示；然而，在只读光盘上的数据是固定的—它们不能被改变。当然，这是与磁盘的读/写能力不同的。

The tremendous amount of low-cost dir-access storage made possible by optical laser disks has opened the door to many new applications.

大量的、低成本直接存取存储器（是光盘使之成为可能）已经打开了通向许多新应用的大门。

CD-R AND CD-RW

CD-R and CD-RW both allow user to store data on compact discs, but only data on rewriteable CDs can be erased and overwritten. CD-R discs can only be written to once. Both types of discs look very similar to CD-ROM discs. Recordable CDs are commonly used to store music files, allowing home users to make high-quality personalized music CDs. CD-RW discs can be written to and erased similar to floppy disk. Consequently, they are a good alternative for large file storage, as well as for creating a “master” disc before burning a CD-R discs(most CD-RW drives can write to both CD-RW and CD- R discs, but some CD and CD-R drives cannot read CD-RW discs). CD-R and CD-RW drives also read CD-ROM discs. However, CDs will be eclipsed BY DVDs, once that technology becomes improved and standardized.

CD-R和CD-RW都允许用户存储数据在光盘上，但是只有那些在可复写cd中的数据能被擦除和重写。Cd-r光盘只能被写入一次。这俩种光盘看起来与只读cd光盘差不多。可记录cd管片通常用于存储音乐文件，这样可以允许家庭用户