When the CD was the future - Developer Diary #6

in #technology6 years ago

Hello Everyone

A long time has passed since the compact disc or CD as it is mostly known was launched, in fact, it is one of the great steps of the technology given to the data capacity meant that can be saved with respect to the elements that the preceded. These days while I was looking for information about technology, I was suggested a video of the ABC where the CD was presented as the great technological revolution, you can see it if you want here below:

Tell me in the comments What was the first CD that you remember reproducing? And what was the first music CD that you bought? If we understand the great feat behind the conception of the CD, we would be shocked to see how two large companies joined forces to get ahead standard nowadays of music. Sony and Phillips collaborated in the creation of the CD to bring together the projects that each of the companies focused on the elimination of LongPlay (LP) or also called Vinyl records, on the part of Phillips. Their research helped in the way which would record the information, the form in which it would be reproduced and in the way of placing files with the EFM system which technically corresponded to:

"In EFM the data to be stored is first cut into blocks of 8 bits, each 8-bit block is translated into its corresponding 14-bit code word, chosen so that the binary data is separated by a minimum of two and a maximum of ten binary zeros, this is because a binary one is stored on the disk as a change from a crest to a valley, while a binary zero is recorded without making changes, since EFM ensures that there are at least two zeros Between each pair, it also ensures that each peak and each valley contains at least three clock cycles, which reduces the requirements of the optical pickup system used in the reproduction mechanism. The maximum of ten consecutive zeros ensures the recovery of the signal from clock in the worst case. "

For its part, Sony supports the project in the creation of a combination of materials that will help the conductivity and the durability of the disk through the CIRC system, which in words cut was "error found, error corrected" it looked for errors on the surface of the disc when it was reproduced by fixing problems when they were generated by the small scratches on it.

For the standardization of the CD as the only method of reproduction of audio Phillips and Sony created a series of books that explained to a greater extent the technology that should be used to create a CD, the way in which the information should be recorded on the disc and the way in which the players understand the structure of the disc, all these books were separated by themes with a respective color, this was called "Rainbow Books". The colors with which the themes were separated were: Orange Red, Green, Yellow, Beige, White *, Blue, Scarlet, Purple.

Two of the most important are Red and Orange, in Red we can see:

  1. The first area on any CD in the 0.4 mm innermost of the disc contains a list of the positions or ID where the audio tracks are located, this list is technically called TOC
  2. The maximum guaranteed duration of a disc with this structure is 74 minutes
  3. The system is designed for continuous repetition since it has a constant linearity

Physical structure of the CDDisctronics

For the book Orange, you can rescue the information about the recordable discs by laser little powerful as they can be the reproducers of our computers (for the people who still have a PC with reproducer since it is being more common that they come without this ), information about discs that can be rewritten is also described.

Do not forget to show my Patreon page and if you can support I would be very thankful https://www.patreon.com/MikeWrite

Sort:  

I always like reading about this stuff that was new when I was young and that is somehow out-dated today :)

Thanks!

Welcome Mike, check steemSTEM community on Discord, to find out the rules, style, to avoid common mistakes and so on...





This post has been voted on by the SteemSTEM curation team and voting trail in collaboration with @curie.

If you appreciate the work we are doing then consider voting both projects for witness by selecting stem.witness and curie!

For additional information please join us on the SteemSTEM discord and to get to know the rest of the community!