Yellow Book (CD standard)

Yellow Book (CD standard). The Yellow Book is the formal standard, published by Sony and Philips in 1988, that defines the format for Compact Disc Read-Only Memory (CD-ROM) media. It extended the earlier Red Book (CD standard) for Compact Disc Digital Audio by specifying how digital data, rather than just audio, could be stored and retrieved from an Optical disc. This foundational specification enabled the CD-ROM to become the primary distribution medium for Computer software, Multimedia, and reference works like Encyclopædia Britannica, revolutionizing the Personal computer industry and Information technology.

Overview

The Yellow Book standard fundamentally distinguishes between Mode 1 and Mode 2 data structures. Mode 1 incorporates Error detection and correction codes, such as Layer 2 Error Correction, making it suitable for critical computer data where integrity is paramount. Mode 2 omits some of this overhead, allowing for greater data capacity and is often used for Compressed audio or Video streams. The standard defines the physical Sector (computer disk) layout and the logical file system, which was later standardized separately as ISO 9660 by the International Organization for Standardization. This separation allowed the Yellow Book to serve as the physical layer, while ISO 9660 ensured File system interoperability across different operating systems like Microsoft Windows, Classic Mac OS, and Unix.

Technical specifications

Physically, a Yellow Book CD-ROM shares the same dimensions as an Audio CD, with a diameter of 120 mm and a polycarbonate substrate. Data is stored as a series of Pit (CD) and Land (CD) formations read by a Laser diode. The standard specifies a data capacity of up to 737 MB (≈ 650 MiB) for Mode 1, translating to roughly 74 minutes of audio-equivalent storage. The data transfer rate, defined by the original CD-ROM drives, was 150 KiB/s (KB/s), a unit later known as "1x" speed. Key technical innovations include the use of Cross-interleaved Reed–Solomon coding (CIRC) for basic error correction, supplemented by an additional Error correction code layer in Mode 1. The Subcode channels (P-W subcode) from the Red Book (CD standard) are repurposed for data indexing and timing information.

Development and history

The development of the Yellow Book was driven by the collaborative efforts of Sony and Philips, the co-creators of the original Compact Disc. Following the success of the Red Book (CD standard) for music, engineers recognized the potential of the Optical disc format for general Data storage. The first official edition was released in 1988, building upon the physical specifications laid out in the Rainbow Books series. Early adoption was seen in products like Microsoft's Microsoft Bookshelf and Grolier's Electronic Encyclopedia. A significant evolution came with the 1991 introduction of CD-ROM XA (eXtended Architecture), a bridge standard developed by Sony, Philips, and Microsoft that merged Yellow Book Mode 2 with ADPCM audio, paving the way for the Green Book (CD standard) for CD-i and the White Book (CD standard) for Video CD.

Impact and adoption

The impact of the Yellow Book standard was transformative, creating an entire industry around CD-ROM publishing. It enabled the mass distribution of large software applications, such as Microsoft Office and Adobe Photoshop, and was crucial for multimedia titles like Myst and Microsoft Encarta. The CD-ROM drive became a standard component in Personal computers throughout the 1990s, notably in systems from Apple (Power Macintosh) and IBM-compatible PCs. It also facilitated the creation of vast digital libraries and was instrumental in projects like the Library of Congress digital initiatives. The standard's success directly led to the development of higher-capacity formats like the DVD and Blu-ray Disc, which inherited its core logical principles.

Related standards

The Yellow Book is one volume in the comprehensive set of Rainbow Books that define all Compact Disc formats. It is directly derived from the Red Book (CD standard) for audio CDs. Its extensions include CD-ROM XA and the Blue Book (CD standard) for Enhanced Music CD. The Green Book (CD standard) defines the CD-i interactive format, while the Orange Book (CD standard) covers recordable discs like CD-R and CD-RW. The White Book (CD standard) for Video CD and the Scarlet Book for Super Audio CD also build upon this foundation. The logical file system most commonly associated with it, ISO 9660, was later extended by the Joliet (file system) from Microsoft and the Universal Disk Format (UDF) used on DVD-Video.

Category:Computer storage media Category:CD-ROM Category:Computer standards Category:1988 in technology