LV-ROM is an

optical disc In computing and optical disc recording technologies, an optical disc (OD) is a flat, usually circular disc that encodes binary data (bits) in the form of pits and lands on a special material, often aluminum, on one of its flat surfaces. ...

format developed by

Philips Electronics Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters is ...

to integrate

analog video Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) syst ...

and

computer software Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work. At the lowest programming level, executable code consists ...

for interactive

multimedia Multimedia is a form of communication that uses a combination of different content forms such as text, audio, images, animations, or video into a single interactive presentation, in contrast to tradi ...

. The LV-ROM is a specialized variation of the

CAV CAV and Cav may refer to: * Cav., in botany, a designator for plants named by Antonio José Cavanilles * ''Cavaliere'' or Cav., an Italian order of knighthood * '' Cavalleria rusticana'', an opera often played as a double bill with ''Pagliacci'', ...

Laserdisc. ''LV-ROM'' is an initialism for "LaserVision Read-Only Memory". Like Laserdisc, LV-ROM discs store

analog Analog or analogue may refer to: Computing and electronics * Analog signal, in which information is encoded in a continuous variable ** Analog device, an apparatus that operates on analog signals *** Analog electronics, circuits which use analo ...

audio and video by encoding it in

pulse-width modulation Pulse-width modulation (PWM), or pulse-duration modulation (PDM), is a method of reducing the average power delivered by an electrical signal, by effectively chopping it up into discrete parts. The average value of voltage (and current) fed ...

. However, LV-ROM also stores

computer file A computer file is a computer resource for recording data in a computer storage device, primarily identified by its file name. Just as words can be written to paper, so can data be written to a computer file. Files can be shared with and trans ...

s via the Advanced Disc Filing System, which is the

file system In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one lar ...

used by

Acorn Computers Acorn Computers Ltd. was a British computer company established in Cambridge, England, in 1978. The company produced a number of computers which were especially popular in the United Kingdom, UK, including the Acorn Electron and the Acorn Archi ...

. An LV-ROM disc can store up to 324 megabytes of

digital information Digital data, in information theory and information systems, is information represented as a string of discrete symbols each of which can take on one of only a finite number of values from some alphabet, such as letters or digits. An example i ...

, or up to 54,000 frames of analog video (36 minutes with a

frame rate Frame rate (expressed in or FPS) is the frequency (rate) at which consecutive images ( frames) are captured or displayed. The term applies equally to film and video cameras, computer graphics, and motion capture systems. Frame rate may also ...

of 25 fps) per side. The format had only one application: to publish documentary video, children's writings, and other historical records compiled from 1984 to 1986 for the

BBC Domesday Project The BBC Domesday Project was a partnership between Acorn Computers, Philips, Logica, and the BBC (with some funding from the European Commission's ESPRIT programme) to mark the 900th anniversary of the original ''Domesday Book'', an 11th-cen ...

. The Domesday Project LV-ROM discs were played using a

BBC Master The BBC Master is a home computer released by Acorn Computers in early 1986. It was designed and built for the British Broadcasting Corporation (BBC) and was the successor to the BBC Micro Model B. The Master 128 remained in production until 199 ...

computer connected via

SCSI-1 Parallel SCSI (formally, SCSI Parallel Interface, or SPI) is the earliest of the interface implementations in the SCSI family. SPI is a parallel bus; there is one set of electrical connections stretching from one end of the SCSI bus to the oth ...

The

, introduced by

in 1986, was one of the first home computers to feature the new SCSI-1

parallel communication In data transmission, parallel communication is a method of conveying multiple binary digits (bits) simultaneously using multiple conductors. This contrasts with serial communication, which conveys only a single bit at a time; this distinction i ...

bus A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a road vehicle that carries significantly more passengers than an average car or van. It is most commonly used in public transport, but is also in use for cha ...

. to a Philips AIV VP415 Laserdisc player. A

genlock Genlock (generator locking) is a common technique where the video output of one source (or a specific reference signal from a signal generator) is used to synchronize other picture sources together. The aim in video applications is to ensure the ...

enabled the software stored on the LV-ROM to display

computer graphics Computer graphics deals with generating images with the aid of computers. Today, computer graphics is a core technology in digital photography, film, video games, cell phone and computer displays, and many specialized applications. A great deal ...

over the analog video on the BBC Master's computer screen. The buttons and menus of the

user interface In the industrial design field of human–computer interaction, a user interface (UI) is the space where interactions between humans and machines occur. The goal of this interaction is to allow effective operation and control of the machine f ...

were accessed with a

trackball A trackball is a pointing device consisting of a ball held by a socket containing sensors to detect a rotation of the ball about two axes—like an upside-down ball mouse with an exposed protruding ball. Users roll the ball to position the on ...

LD-ROM

In the early 1990s,

Pioneer Corporation commonly referred to as Pioneer, is a Japanese multinational corporation based in Tokyo, that specializes in digital entertainment products. The company was founded by Nozomu Matsumoto in January 1, 1938 in Tokyo as a radio and speaker repair ...

deployed a variation of the 30-cm LV-ROM with a different

and a 540 megabyte capacity. This disc format, called LD-ROM, stored the software for a home entertainment system that Pioneer introduced in 1993. This system, the Pioneer LaserActive, was a

cross-platform In computing, cross-platform software (also called multi-platform software, platform-agnostic software, or platform-independent software) is computer software that is designed to work in several computing platforms. Some cross-platform software ...

video game console A video game console is an electronic device that outputs a video signal or image to display a video game that can be played with a game controller. These may be home consoles, which are generally placed in a permanent location connected to ...

, Laserdisc player, and

CD player A CD player is an electronic device that plays audio compact discs, which are a digital optical disc data storage format. CD players were first sold to consumers in 1982. CDs typically contain recordings of audio material such as music or au ...

. LD-ROMs owe their greater capacity to a design for

constant linear velocity In optical storage, constant linear velocity (CLV) is a qualifier for the rated speed of an optical disc drive, and may also be applied to the writing speed of recordable discs. CLV implies that the angular velocity (i.e. rpm) varies during an ...

(CLV) playback. Like

magnetic tape Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use mag ...

, the playback speed corresponds with picture quality and audio definition of analog audio-video streams. Since Pioneer intended LD-ROMs primarily for computer software, they chose CLV technology to increase the file storage capacity. Specialized LD-ROM discs include the MEGA LD (for Sega Mega CD/Sega CD software), the LD-G (for

karaoke Karaoke (; ; , clipped compound of Japanese ''kara'' "empty" and ''ōkesutora'' "orchestra") is a type of interactive entertainment usually offered in clubs and bars, where people sing along to recorded music using a microphone. The music i ...

data or digital photo albums; similar to

CD+G CD+G (also known as CD-G, CD+Graphics and TV-Graphics) is an extension of the compact disc standard that can present low-resolution graphics alongside the audio data on the disc when played on a compatible device. CD+G discs are often used for ...

), and the LD-ROM² (for PC-Engine CD-ROM² software). Such software was published either on 30-centimeter discs or on 20-centimeter discs with a lesser storage capacity. Whereas ''LV-ROM'' is an abbreviation of "LaserVision

Read-Only Memory Read-only memory (ROM) is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM cannot be electronically modified after the manufacture of the memory device. Read-only memory is useful for storing s ...

", ''LD-ROM'' is an abbreviation of "LaserDisc Read-Only Memory".

LD-ROM

References

See also