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Buffer/Cache-most drives are shipped with internal buffers or caches of memory installed on-board.These buffers are actual memory chips installed on the drive's board and allow data to be staged or stored in larger segments before they are sent to the PC. A typical buffer for a CD-ROM drive is 256 kilobytes or KB,
although drives are available that have either more or less(more is generally better). Generally the faster speed drives will come with more buffer to handle the higher transfer rates.Having buffer or cache memory on the CD-ROM drive offers a number of advantages. Buffers can ensure that the PC recieves data at a constant rate; when an application requests data from the CD-ROM disc, the data is probably scattered across different segments of the disk.Because the drive has a relatively slow access time, the pauses between data reads can cause a drive to send data to the PC sporadically.You might not notice this in typical text applications, but a slower access rate drive coupled with no data buffering is very noticeable, even irritating, in the display of video or some audio segments. In addition a drive's buffer, when under control of sophisticated software, can read and have ready disc's table of contents, making the first request for the data faster to find on the disc platter. A minimum of 256 KB is highly recommended size of a buffer or cache standard on most Quad-speed drives.
Interface-A CD-ROM's interface is the physical connection of the drive to the PC's expansion bus. The interface is the pipeline of data from the drive to the computer, and its importance shouldn't be minimized. There are three types of interfaces available for attaching aCD-ROM drive to your system. They are:
* SCSI/ASPI(Small Computer System Interface/Advanced SCSI Programming Interface)
* IDE/ATAPI(Integrated Device Electronics/AT Attachment Packet Interface)
* Proprietary
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