| The data is separated into blocks,
which are read at a constant rate of 75 blocks per second. Each disk can hold 74 minutes
of information, resulting in a maximum of 333,000 blocks. Each block contains 2,352 bytes;
simple arithmetic shows the absolute maximum storage capacity of a disc to be 681,984,000
bytes. An added feature of audio CD’s is that in the event of damage, the missing data can be interpolated; that is to say, the information follows a predictable pattern that allows the missing value to be guessed at. So if an audio CD is damaged by dirt or a scratch, the missing data can be averaged from a pattern with no noticable difference to the listener. This is something the next technology in optical digital memory, CD-ROM, cannot do because an executable program’s data doesn’t follow a natural law. An interpolation-based guess isn’t just slightly different; it's completely wrong. Because of this precision, CD-ROM drives for PC’s came later and much more expensive than audio. |