Pioneer PR7820
Encyclopedia
The Pioneer PR7820 was the first mass-produced industrial laserdisc
player, sold originally as the MCA DiscoVision PR-7820. This unit was used in many General Motors
dealerships as a source of training videos and presentation of GM's new line of car
s and truck
s in the late 1970s and early 1980s. After MCA DiscoVision shut down, Pioneer
continued to sell the player under the Pioneer name as the Pioneer Model-III. The unit was a full Level-III player and could accept a data-dump from discs themselves. It could also be controlled by an external computer
and could be genlock
ed to external video sources.
on top (instead of underneath) and moving the disc radially to provide tracking
instead of moving the laser radially. MCA engineers designed the player at the DiscoVision labs in Torrance, California
and Universal-Pioneer mass produced it in Japan
. The 7820 was such a high quality player that MCA themselves used it at their DiscoVision disc pressing plant in Carson, California
for quality control checks of both master discs and finished sets. Unfortunately, this caused problems because the 7820 could easily play discs that the consumer player, the Magnavox
VH-8000, could not cope with.
that increased the total size of a disc-based computer program
the 7820 could store and execute to 256k.
delay line to provide tangential tracking corrections, giving the player superb color quality. It wasn't until 1985/6 that the tangential mirror began to be replaced by electronic correction, first by Yamaha
in their first consumer LD player, and eventually, by Pioneer themselves.
for the PR-7820. Depending on the number purchased, it varied from $3,500 to $2,200 per unit if more than 1000 were bought at once. Fully functional 7820s are not easily available on eBay
and are nearly impossible to find in fully functional condition. Because they have a steel chassis, weight is a shipping problem.
Laserdisc
LaserDisc was a home video format and the first commercial optical disc storage medium. Initially licensed, sold, and marketed as MCA DiscoVision in North America in 1978, the technology was previously referred to interally as Optical Videodisc System, Reflective Optical Videodisc, Laser Optical...
player, sold originally as the MCA DiscoVision PR-7820. This unit was used in many General Motors
General Motors
General Motors Company , commonly known as GM, formerly incorporated as General Motors Corporation, is an American multinational automotive corporation headquartered in Detroit, Michigan and the world's second-largest automaker in 2010...
dealerships as a source of training videos and presentation of GM's new line of car
Čar
Čar is a village in the municipality of Bujanovac, Serbia. According to the 2002 census, the town has a population of 296 people.-References:...
s and truck
Truck
A truck or lorry is a motor vehicle designed to transport cargo. Trucks vary greatly in size, power, and configuration, with the smallest being mechanically similar to an automobile...
s in the late 1970s and early 1980s. After MCA DiscoVision shut down, Pioneer
Pioneer Corporation
is a multinational corporation that specializes in digital entertainment products, based in Kawasaki, Kanagawa, Japan. The company was founded in 1938 in Tokyo as a radio and speaker repair shop...
continued to sell the player under the Pioneer name as the Pioneer Model-III. The unit was a full Level-III player and could accept a data-dump from discs themselves. It could also be controlled by an external computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
and could be genlock
Genlock
Genlock 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 television picture sources together. The aim in video and digital audio applications is to ensure the coincidence of signals in time at a...
ed to external video sources.
Overview
The 7820 is the only player ever sold to either the industrial or consumer market that was entirely designed and engineered by the technicians at MCA Disco-Vision and contained all of their preferred design approaches, such as playing the disc with the laserLaser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...
on top (instead of underneath) and moving the disc radially to provide tracking
Tracking
Tracking can refer to:*Tracking , separating children into different classes according to their academic ability*Tracking, in computer graphics, a vital part of match moving...
instead of moving the laser radially. MCA engineers designed the player at the DiscoVision labs in Torrance, California
Torrance, California
Torrance is a city incorporated in 1921 and located in the South Bay region of Los Angeles County, California, United States. Torrance has of shore-front beaches on the Pacific Ocean, quieter and less well-known by tourists than others on the Santa Monica Bay, such as those of neighboring...
and Universal-Pioneer mass produced it in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
. The 7820 was such a high quality player that MCA themselves used it at their DiscoVision disc pressing plant in Carson, California
Carson, California
Carson is a city in Los Angeles County, California. As of the 2010 census, Carson had a total population of 91,714. Located south of downtown Los Angeles and approximately 14 miles away from the Los Angeles International Airport, it is known as a suburb of the city....
for quality control checks of both master discs and finished sets. Unfortunately, this caused problems because the 7820 could easily play discs that the consumer player, the Magnavox
Magnavox
Magnavox is a US electronics company founded by Edwin Pridham and Peter L. Jensen, who invented the moving-coil loudspeaker in 1915 at their lab in Napa, California. They formed Magnavox in 1917 in order to market their inventions....
VH-8000, could not cope with.
Updates
In 1980, Discovision Associates released a factory update (it could also be retrofitted to existing 7820s) that reduced disc search times to less than 3 seconds, and added the ability to jump up to 99 tracks during vertical blanking, giving essentially "instant" searches. An external computer interface box was also made available at the same time which contained additional memoryComputer memory
In computing, memory refers to the physical devices used to store programs or data on a temporary or permanent basis for use in a computer or other digital electronic device. The term primary memory is used for the information in physical systems which are fast In computing, memory refers to the...
that increased the total size of a disc-based computer program
Computer program
A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...
the 7820 could store and execute to 256k.
Tracking
The 7820 was the first LD player to use solid-state tangential tracking — instead of a tangential tracking mirror, the 7820 used an electronic CCDCharge-coupled device
A charge-coupled device is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This is achieved by "shifting" the signals between stages within the device one at a time...
delay line to provide tangential tracking corrections, giving the player superb color quality. It wasn't until 1985/6 that the tangential mirror began to be replaced by electronic correction, first by Yamaha
Yamaha
Yamaha may refer to:* Yamaha Corporation, a Japanese company with a wide range of products and services** Yamaha Motor Company, a Japanese motorized vehicle-producing company...
in their first consumer LD player, and eventually, by Pioneer themselves.
Pricing
MCA DiscoVision had no suggested retail priceSuggested retail price
The manufacturer's suggested retail price , list price or recommended retail price of a product is the price which the manufacturer recommends that the retailer sell the product. The intention was to help to standardise prices among locations...
for the PR-7820. Depending on the number purchased, it varied from $3,500 to $2,200 per unit if more than 1000 were bought at once. Fully functional 7820s are not easily available on eBay
EBay
eBay Inc. is an American internet consumer-to-consumer corporation that manages eBay.com, an online auction and shopping website in which people and businesses buy and sell a broad variety of goods and services worldwide...
and are nearly impossible to find in fully functional condition. Because they have a steel chassis, weight is a shipping problem.