Feeds

Compact Disc: 25 years old today

First commercial disc pressed on 17 August 1982

  • alert
  • submit to reddit

Secure remote control for conventional and virtual desktops

The development of the CD stretches back to 1979 when Sony and Philips established an engineering team to create a disc capable of stopring music in digital form. According to Philips, the original design spec called for a 11.5cm-diameter disc capable of holding an hour's music, but this was later extended to 12cm and 74m minutes - sufficient to accomodate the whole of Beethoven's 9th Symphony. Some writers claim this was driven by Sony co-founder Akio Morita, in order to ensure his favourite symphony could be stored on a single disc.

Philips launches CD
Philips' Joop Sinjou introduces the CD in 1979

In June 1980, the development specification was frozen and enshrined in what the partners called the Red Book. Later, the arrival of the Yellow Book would see the publication of the CD-Rom specification for computer use.

It might be assumed that the CD's digital encoding is sufficient to ensure perfect fidelity. Not so. Poor laser focusing, discs that wobble as they spin introduce noise into the signal, and the inevitable dust and fingerprints that accumulate on the surface, forcing the format's developers to come up with some clever error-correction technology to compensate. Indeed, listen to a disc without the special encoding, and there's almost as much hiss as music, and arguably worse than the sound produced by cassette tape.

Pink Floyd's Dark Side of the Moon
Pink Floyd's Dark Side of the Moon: own, dedicated CD plant?

To get around the problem, CD uses a technique called eight-fourteen modulation (EFM) developed by Dutch digital recording boffin Kornelis Antonie Schouhamer Immink. The data stream is broken into blocks, each eight bits long - and half of the 16 bits used to encode the sample of the soundwave taken 44,100 times a second. The eight-bit block is matched against a list of possible bit patterns and a 14-bit code read off the table, hence eight-fourteen.

Beginner's guide to SSL certificates

More from The Register

next story
Xperia Z3: Crikey, Sony – ANOTHER flagship phondleslab?
The Fourth Amendment... and it IS better
Don't wait for that big iPad, order a NEXUS 9 instead, industry little bird says
Google said to debut next big slab, Android L ahead of Apple event
Microsoft to enter the STRUGGLE of the HUMAN WRIST
It's not just a thumb war, it's total digit war
Ex-US Navy fighter pilot MIT prof: Drones beat humans - I should know
'Missy' Cummings on UAVs, smartcars and dying from boredom
Netscape Navigator - the browser that started it all - turns 20
It was 20 years ago today, Marc Andreeesen taught the band to play
A drone of one's own: Reg buyers' guide for UAV fanciers
Hardware: Check. Software: Huh? Licence: Licence...?
The Apple launch AS IT HAPPENED: Totally SERIOUS coverage, not for haters
Fandroids, Windows Phone fringe-oids – you wouldn't understand
Apple SILENCES Bose, YANKS headphones from stores
The, er, Beats go on after noise-cancelling spat
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.