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 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 tradition ...

. The LV-ROM is a specialized variation of the CAV

Laserdisc The LaserDisc (LD) is a home video format and the first commercial optical disc storage medium, initially licensed, sold and marketed as DiscoVision, MCA DiscoVision (also known simply as "DiscoVision") in the United States in 1978. Its diam ...

. ''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 transfe ...

s via the

Advanced Disc Filing System The Advanced Disc Filing System (ADFS) is a computing file system unique to the Acorn computer range and RISC OS-based successors. Initially based on the rare Acorn Winchester Filing System, it was renamed to the Advanced Disc Filing System when ...

, 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 larg ...

used by Acorn Computers. An LV-ROM disc can store up to 324 megabytes of digital information, 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 be ca ...

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 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 BBC, British Broadcasting Corporation (BBC) and was the successor to the BBC Micro, BBC Micro Model B. The Master 128 remained in produ ...

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 Acorn Computers 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 ...

s bus. to a Philips AIV VP415 Laserdisc player. A genlock 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 de ...

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-s ...

LD-ROM

In the early 1990s, Pioneer Corporation 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 The is a Technological convergence, converged device and History of video game consoles (fourth generation), fourth-generation home video game console capable of playing LaserDiscs, Compact Discs, console games, and LD-G karaoke discs. It was rel ...

, 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 r ...

video game console A video game console is an electronic device that Input/output, outputs a video signal or image to display a video game that can be played with a game controller. These may be home video game console, home consoles, which are generally placed i ...

, Laserdisc player, and CD player. 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 magne ...

, 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 is ...

data or digital photo albums; similar to CD+G), 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 sof ...

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

LD-ROM

References

See also