A CD-ROM is a pre-pressed optical compact disc that contains data. Computers can read—but not write to or erase—CD-ROMs, i.e. it is a type of read-only memory. During the 1990s, CD-ROMs were popularly used to distribute software and data for computers and fourth generation video game consoles; some CDs, called enhanced CDs, hold both computer data and audio with the latter capable of being played on a CD player, while data is only usable on a computer. The CD-ROM format was developed by Japanese company Denon in 1982, it was an extension of Compact Disc Digital Audio, adapted the format to hold any form of digital data, with a storage capacity of 553 MiB. CD-ROM was introduced by Denon and Sony at a Japanese computer show in 1984; the Yellow Book is the technical standard. One of a set of color-bound books that contain the technical specifications for all CD formats, the Yellow Book, standardized by Sony and Philips in 1983, specifies a format for discs with a maximum capacity of 650 MiB. CD-ROMs are identical in appearance to audio CDs, data are stored and retrieved in a similar manner.
Discs are made from a 1.2 mm thick disc of polycarbonate plastic, with a thin layer of aluminium to make a reflective surface. The most common size of CD-ROM is 120 mm in diameter, though the smaller Mini CD standard with an 80 mm diameter, as well as shaped compact discs in numerous non-standard sizes and molds, are available. Data is stored on the disc as a series of microscopic indentations. A laser is shone onto the reflective surface of the disc to read the pattern of lands; because the depth of the pits is one-quarter to one-sixth of the wavelength of the laser light used to read the disc, the reflected beam's phase is shifted in relation to the incoming beam, causing destructive interference and reducing the reflected beam's intensity. This is converted into binary data. Several formats are used for data stored on compact discs, known as the Rainbow Books; the Yellow Book, published in 1988, defines the specifications for CD-ROMs, standardized in 1989 as the ISO/IEC 10149 / ECMA-130 standard.
The CD-ROM standard builds on top of the original Red Book CD-DA standard for CD audio. Other standards, such as the White Book for Video CDs, further define formats based on the CD-ROM specifications; the Yellow Book itself is not available, but the standards with the corresponding content can be downloaded for free from ISO or ECMA. There are several standards that define how to structure data files on a CD-ROM. ISO 9660 defines the standard file system for a CD-ROM. ISO 13490 is an improvement on this standard which adds support for non-sequential write-once and re-writeable discs such as CD-R and CD-RW, as well as multiple sessions; the ISO 13346 standard was designed to address most of the shortcomings of ISO 9660, a subset of it evolved into the UDF format, adopted for DVDs. The bootable CD specification was issued in January 1995, to make a CD emulate a hard disk or floppy disk, is called El Torito. Data stored on CD-ROMs follows the standard CD data encoding techniques described in the Red Book specification.
This includes cross-interleaved Reed–Solomon coding, eight-to-fourteen modulation, the use of pits and lands for coding the bits into the physical surface of the CD. The structures used to group data on a CD-ROM are derived from the Red Book. Like audio CDs, a CD-ROM sector contains 2,352 bytes of user data, composed of 98 frames, each consisting of 33-bytes. Unlike audio CDs, the data stored in these sectors corresponds to any type of digital data, not audio samples encoded according to the audio CD specification. To structure and protect this data, the CD-ROM standard further defines two sector modes, Mode 1 and Mode 2, which describe two different layouts for the data inside a sector. A track inside a CD-ROM only contains sectors in the same mode, but if multiple tracks are present in a CD-ROM, each track can have its sectors in a different mode from the rest of the tracks, they can coexist with audio CD tracks as well, the case of mixed mode CDs. Both Mode 1 and 2 sectors use the first 16 bytes for header information, but differ in the remaining 2,336 bytes due to the use of error correction bytes.
Unlike an audio CD, a CD-ROM cannot rely on error concealment by interpolation. To achieve improved error correction and detection, Mode 1, used for digital data, adds a 32-bit cyclic redundancy check code for error detection, a third layer of Reed–Solomon error correction using a Reed-Solomon Product-like Code. Mode 1 therefore contains 288 bytes per sector for error detection and correction, leaving 2,048 bytes per sector available for data. Mode 2, more appropriate for image or video data, contains no additional error detection or correction bytes, having therefore 2,336 available data bytes per sector. Note that both modes, like audio CDs, still benefit from the lower layers of error correction at the frame level. Before being stored on a disc with the techniques described above, each CD-ROM sector is scrambled to prevent some problematic patterns from showing up; these scrambled sectors follow the same encoding process described in the Red Book in order to be stored
Bartolomeo Minio was, among other things, a Venetian captain and commander of Napoli di Romagna, a Venetian outpost on the Morea from 1479 to 1483. His reports to Venice provide a unique historical source for southern Greece in the 15th century, during the first decades of the Ottoman occupation; the Minio family records date back to 904. In the 14th century, Bartolomeo's family held many office positions and were counted in the estimo of 1379. Nine members of his family were listed in Karl Hopf's catalogues of governors for Greece and the Aegean islands. Bartolomeo was born in Venice in around 1428 to Marco Minio and Cristina Storlado, the youngest of five sons. Cristina died when Bartolomeo was only two years old and Marco remarried in 1431. In 1455, Bartolomeo married Elena Trevisan. Three sons were known to have reached adulthood; the family house can be identified in the San Tomà parish of the San Polo sestiere of Venice. In 1462, Bartolomeo was a consiliere to the rettor of Corfu during his early career in the Stato da Màr, Venice's overseas colonies.
Minio spent over forty-two months in Nauplion beginning in November 1479. His term is notable for the fortifications he built for Nauplion, for his settlement of the territorial boundaries with the Ottomans, for his judicious settlement of the Kladas revolt. In 1499 and 1500, he was stationed in Cyprus where he made notable contributions to the fortifications of Famagusta. Between 1500 and 1502, he was captain in Venetian Crete. A collection of 60 reports which he made during that time has survived; these reports, combined with the 90 from Nauplion, form an incomparable collection of letters by a single person. An edition of these letters by Diana G. Wright and John R. Melville-Jones, accompanied by a translation and commentary, has been published by UniPress, Italy, his career in Venice and the mainland followed the normal course for Venetian patricians: in 1497, he was a councillor for water issues in the Terraferma. In 1509, at the age of 80, he was sent to Julius II in order to discuss matters pertaining to the papal interdict placed on Venice for the capture of Ravenna and Faenza.
He was appointed provveditore of the stratioti for the Ferrara War in 1484. In 1485, he was elected captain of the annual Venetian trading convoy from Venice to Flanders and England. In the Bay of Biscay, the convoy of four galleys was attacked by pirates, one of whom was Christopher Columbus, the merchandise was taken, Minio and the survivors left on the coast of Portugal. Bartolomeo had periods of illness prior to his death. After missing vespers on April 25, 1512, he sent a message a week to the Collegio rejecting his position as vice-doge due to his illness, he was ill again and missed two major ceremonial events in May and June 1513. Despite all this, he became consiliere of Padua in October 1515 after a meeting of the Ten that lasted until the eleventh hour of the day. In August or September 1518, Bartolomeo Minio died at the age of ninety. Colón, Ferdinand; the Life of the Admiral Christopher Columbus. Rutgers, NJ: Rutgers University Press. ISBN 978-0-81-351801-5
Tommaso Balestrieri was an Italian luthier in Mantua active from 1750s to 1780s. Balestrieri's origin is not well established, his violin labels identify him to be from Cremona. He was born around 1735 and moved to Mantua in life, his first known works were produced in Mantua and date to the mid-1750s, his last works date to mid-1790s. Balestrieri was one of the last masters of the Cremonese violin-making tradition – a tradition, established by four generations of the Amati family, it is not clear where. Other luthiers in Mantua whose works were rooted in the Cremonese Amati tradition were Pietro Giovanni Guarneri, Camillo Camilli, Antonio Zanotti. Balestrieri's early works were delicate and in line with the Amati tradition, but soon he started to incorporate more muscular and robust features in his designs – in line with Stradivari's designs; the materials used indicate an emphasis for performance over appearance. According to instrument maker John Dilworth, Balestrieri's works have a "full sound and forceful appearance they may not be the most refined of violins in craftsmanship, but rival the best in performance."
Chart of Cremonese violin-making tradition