#Easy cd data extractor series

On a new, blank CD, all of the material in the writable area is in the crystalline form, so light will shine through this layer to the reflective metal above and bounce back to the light sensor. In the compound used in CD-RW discs, the crystalline form is translucent while the amorphous fluid form will absorb most light. In order to crystallize the compound, you have to keep it at the crystallization temperature for a certain length of time so that it turns into a solid before it cools down again. If you heat the compound in CD-RW discs to the melting temperature and let it cool rapidly, it will remain in a fluid, amorphous state, even though it is below the crystallization temperature. In phase-change compounds, these shifts in form can be 'locked into place': They persist even after the material cools down again. You also need a blank disc that is designed to record information at this speed. For faster burning speeds, you need more advanced laser-control systems and a faster connection between the computer and the burner. At 2x speed, it would take you about half an hour to record 60 minutes, and so on. This means it would take you about 60 minutes to record 60 minutes of music. At 1x speed, the CD spins at about the same rate as it does when the player is reading it. Most CD burners can create CDs at multiple speeds. The laser darkens the material to encode a 0 and leaves it translucent to encode a 1. To record the data, the burner simply turns the laser writer on and off in synch with the pattern of 1s and 0s. By calibrating the rate of spin with the movement of the laser assembly, the burner keeps the laser running along the track at a constant rate of speed. The bottom plastic layer has grooves pre-pressed into it, to guide the laser along the correct path. The write laser moves in exactly the same way as the read laser: It moves outward while the disc spins. There is a mechanism that spins the disc and another mechanism that slides the laser assembly. The machinery in a CD burner looks pretty much the same as the machinery in any CD player. When the beam passes over a bump, the light is bounced away from the optical sensor. When the laser passes over a flat area in the track, the beam is reflected directly to an optical sensor on the laser assembly.

To read this information, the CD player passes a laser beam over the track. The bumps and flats are arranged in a continuous track that measures about 0.5 microns (millionths of a meter) across and 3.5 miles (5 km) long. In conventional CDs, these 1s and 0s are represented by millions of tiny bumps and flat areas on the disc's reflective surface.

#Easy cd data extractor series

CDs store music and other files in digital form - that is, the information on the disc is represented by a series of 1s and 0s (see How Analog and Digital Recording Works for more information). If you've read How CDs Work, you understand the basic idea of CD technology. If you were to unwind this track, it would extend out 3.5 miles (5 km).