The CD-ROM (compact disc read only memory) has been a very big part of the PC. Without it you will have a hard time getting software for your computer. With it you have opened many doors to yourself. The sad part is almost all software comes in the form of CD-ROM and if you don’t have one you are basically screwed. The CD-ROM is very attractive to the software makers because it can hold more per disk than the floppy. The floppy holds 1.44 MB per disk while the CD-ROM holds 650 MB per disk. Big difference in size and cheaper to manufacturer these days.
-CD players found there life in the universe replacing the old LP’s and cassette tapes. Someone along the line seen the usefulness in a PC format and boom we all have CD-ROM’s. These players are used in almost all new PC’s shipped today. Now with saying that what is the CD-ROM and how does it interact with the PC?
-The conventional drive uses magnetics to read and write to disk. The CD-ROM however uses light (laser) to read small data in the aluminum alloy coating of the disc. The laser reads and writes (CD-writers) to the CD surface. If a pit exist in the surface of the disk this is interpreted as a binary 1 and no pit means a 0 this is called land to pit. Pretty similar to a record but in a digital format.
-Of course the CD-ROM has to come in speeds. When you shop for a CD-ROM you will notice that there is a speed associated with the drive such as a 32x CD-ROM. A 1x CD-ROM has a data transfer rate of 150 kilobytes per second. This would make your 32x transfer rate 4800 kilobytes per second. That’s not to shabby of a transfer rate and they keep getting higher. Now most manufacturers of newer CD-ROM’s use both CAV and CLV design. This allows the disk to slow down and speed up in certain parts of the disk. If both these technologies are being used it can really help with performance of the CD-ROM and add a more realistic spin speed.
