References and Further info
CED
Imagine a
record player that can play movies. Movies recorded on vinyl records. It seems
surreal, but such a device was developed by Radio Corporation of America (RCA)
and was sold in the 1980s, as a cheaper alterative to laserdiscs and VCRs. Not
surprisingly, it didn’t
do so well, and its credited for destroying RCA. Despite this, the Capacitance
Electronic Disc (CED) system was one of the most successful video from
phonograph record systems ever developed. With one hour of footage per 30cm
diameter side, and players that were basically modified record players (making
them cheap to make), the CED did manage to sell over 500,000 players in total.
However, in the larger scheme of things, it’s a minor footnote in the history of home video
that was obsolete by the time it was launched. A tech curiosity for people
interested in video technology – like me.
Video on Phonograph Records
The idea of recording images in the same way as sound on phonograph records has had a number of implementations since the invention of television. In 1927 John Logie Baird developed a way to record images from his mechanical TV system onto 12-in shellac “78s”. Although he successfully made a number of records, he failed to develop a way to play back the image that worked. It wasn’t until computer technology the 1980s that researchers were able to finally view his recordings.
How the CED came to be
The story and drama of how CED came into being is long,
complicated, and crazy. Enough to warrant its own book, which does exist. It
began in 1951, when David Sarnoff challenged his researchers to create three “gifts”
for him. One of them was a “videograph,” a device that records TV signals onto
magnetic tape. Basically, a video tape recorder. As RCA was pioneering colour
TV at the time, it was insisted that the “videograph” was able to record
colour, which hindered progress so much that Ampex beat them to making the
first practical (blank-and-white) video recorder in 1956. In 1959, while
researching integrated circuits, Thomas Stanley did a side project, researching
the potential of storing information on vinyl records.
In 1964, RCA decided to begin work on a “practical and
low-cost video recorder that would lead to mass market.” Four ideas were tried out, simultaneously.
Magnetic
tape – which some in
RCA scoffed, due to past failure with the “videograph.”
Photopix – A disc or, later, tape of tiny
images scanned by a camera tube. Basically, a larger version of a Viewfinder
toy.
Holopix – A system where a laser makes images
from holographic patterns on a disc or, later, tape that are picked up by a
camera tube.
Discpix – The “least interesting” project, which led to CED.
Progress was slow. Then, in 1967, RCA rival CBS announced the development of their film-based Electronic Video Recording (EVR) system. The existence of this rival product prompted RCA accelerate development. In 1969 RCA demonstrated a Holopix prototype called “SelectaVision.”
The 1970s
was a complicated mess for RCA, with financial loses, internal politics holding
up progress, changes in management and reshuffles and a general loss in
direction. Despite this, development continued. Although the EVR was abandoned
by CBS in 1972, other video formats had came to be, forcing RCA to go up a
gear. By then RCA was managed to squeeze 10 minutes of video per side. By 1975,
RCA had cut all home video projects, except Discpix – and used the “SelectaVision” name on VHS VCRs they licensed from JVC as a
stock cap. With only one system to work on, the people of RCA were finally able
to get alone and make a working product. A working prototype was demonstrated
in 1975, and a 1977 deadline was planned. Then Edgar Griffiths (who hated the
project) took charge of RCA. He let development continue, after managers voted
for its continuation. Then, when Fortune magazine wrote a flattering
article about him, which said he was overly cautious in his approach to
technology-based products, in 1979 Edgar announced they’ll rush the product to market.
Amazingly, a lot of issues the researchers had making the CED were only fixed during these final years. For example, before, researchers experimented with injection moulding to make the discs. The results were not great. Then someone thought “Why don’t we just press discs like we press vinyl records?” This suggestion improved discs spectacularly. A lot of the issues the CED had was solved like this, including the idea of having the disc in a protective caddy. Before, the idea was for a naked disc that is placed on a turntable, just like an audio record player. It’s like they were reinventing the wheel, before realizing why the wheel worked in the first place. YouTuber Alec Watson tells this story better.
"In summary, a bunch of things doomed this poor product. The free rein Labs was given to just do whatever with little regard to practical matters prevented progress from ever being truly coordinated, as did the general resentment of the Labs by other departments. So, years passed without anything to really show for it. Then RCA had lost their way under Robert Sarnoff and just kinda stopped innovating altogether for a while, and by the time [Edgar] Griffiths was in charge, they had just kinda forgotten how to innovate." - Alec Watson, Technology Connections
The first
CED player, the RCA SFT100W, went on sale for $499.95 on 22nd March
1981, along with a library of about 50 titles.
Japan’s copycat?
In 1974, in the hope to make CED a future industry standard, RCA sent a demo to Japan. Although the demo was a disaster, six companies took up the offer, especially Matsushita. For $3,000 they sold a prototype player, some sample discs, and engineering drawings. In 1978, JVC (owned by Matsushita) demonstrated the Video High Density (VHD) videodisc system, which is kind of similar to the CED, but better. It had minor success in 1980s Japan.
Race for
Your Life, Charlie Brown (1977) has the honour of been the movie on the first CED disc ever manufactured. The last
discs ever made was for The Jewel of the Nile (1985) and a commemorative
title given to employees - Memories of VideoDisc.
What
happened to CED?
RCA aimed
to sell 200,00 players by 1982 and to have a player in about 50% of American
homes by 1985. However, because of how long it took to go to market, by the
time the CED was finally ready to sell, two thirds of dealers who signed on to
selling them had backed out. They only sold about 100,000 by 1982. By the end
of 1983, 500,000 players were sold in total. The price of players were slashed
and customers were offered rebates and free discs, but that only improved sales
a bit. However, when it came to selling discs, “…the average purchaser
of this player is also buying from 20 to 30 of these discs in the very first year of ownership.”
This is double than what RCA expected.
On 4th
April 1984, RCA announce the end of production of players. Remaining stock was
sold for as little as $20! But amazingly, after the announcement, sales of
discs shot up! This made RCA announce that they’ll continue making discs with new titles for at
least another three years. But sales fell again. The last CED disc was made in
1986.
Could
the CED been more successful if released earlier?
It can be
argued that if the CED was released years earlier (say 1975-78) it could have
been a much bigger success. RCA assumed that people would buy their movies in
the same way they bought music in the form of LPs and that a player’s cheap price, compared to VCRs,
would justify their purchase. But, by 1981, VCR’s had advanced and become more affordable, and
a video rental market was flourishing, so VCR buyers didn’t need to spend more on owning movies.
Though retailing for about $500, compared to about $1,000 for a basic VCR,
spending that price on a machine that didn’t record, as well as play pre-made content,
seemed silly. However, if many did buy non-recording CED players in the
mid-1970s, it may have been possible for the Hollywood studios to outlaw the
VCR in the US, over possible lost revenue, fundamentally changing home video as
we knew it then.
How many
titles?
RCA did
manage to make a large library of movies during its run – over 1,700 titles in the US and
about 270 in for the UK market. However, the variety of content was limited to
what RCA thought was OK. CED didn’t become successful enough for third party distributors to adopt the
format, allowing more “mature” content on the format. This could
be the origin of the myth of “Betamax failed because Sony didn’t allow smut on their format.”
Caddies
and Disc
The disc is safely stored in a protective caddy, which is slightly bigger than a LP album sleeve - measuring 32 x 35cm. Initially white and in mono, movies with stereo sound or dual soundtracks were later sold in blue caddies, compared to the original white. But some were sold in white caddies. They were black caddies, made to indicate interactive discs, but seven Disney non-interactive titles were sold in black. They were also used for discs not intended for public use, such as dealer demos and test pressings. A small number of grey caddies were made for RCA’s industrial training disc program, which was implemented to a small degree, making them extremely rare to the point some doubt their existence.
CED Disc
(A movie on vinyl)
The 30cm diameter disc (or “12 inch” to avoid the use of metric names) is made of PVC blended with carbon to make it conductive, covered in a thin layer of silicone for lubricant. The disc rotates at a constant angular speed during playback (450 rpm for NTSC, 275 rpm for PAL). It’s this high speed, as well as its means of recording, that a CED is able to store 60 minutes of video per side in NTSC (75 minutes in PAL). This was later pushed to 63 minutes.
Every disc has an ID number printed on the centre, which
corresponds to the barcode printed on the caddy’s label or the stock number on
the edge of the disc. At least four consecutive digits need to match. On side
one of the disc the centre has a concentric barcode. In the disc factory the
machine that inserts discs into caddies reads the barcodes as the disc is
inserted to verify if they match.
The caddy’s opening is lined with strips of felt inside to catch dust and debris in discs while loading/unloading.
The
grooves on a CED disc are 657 nanometres wide – about 32 times thinner than the grooves
on an LP.
Disc is read outside-in, like an LP. A 60-minute CED stores 450 times more information than a 20-minute LP.
Each rotation records eight fields, or four frames, of footage. This can be seen on the disc as “spokes” when viewed in certain lighting. The spokes are the gaps between the fields. Because of this, freeze frame was impossible without an additional electronic framebuffer. But many players had a “page mode,” where, when used, played the same four frames in a loop on screen.
Interactive Discs
On interactive discs the disc is split into up to 63 “chapters” or bands. These chapters are based on minutes of a movie, not scenes, like on DVDs. These were digitally coded by signals stored in the vertical blanking intervals. A few later players were able to access these chapters in any order. Novelty discs and CED-based games were made, where they had to access certain chapters in a specified order to construct a story. Only a few of such games were ever made before the format died.
CED was mostly sold in the US and Canada. But RCA briefly marketed it in the UK and Australia.
Born – 22nd March 1981
Price of Discs – $14.98 to $39.98.
Caddy size – 32.5 x 35.5 x 0.6
cm
Disc Diameter – 30 cm
Rotation Speed - 450 rpm (NTSC)
/ 275 rpm (PAL)
Play
Direction – Outside to centre (like an LP)
Max poss record length – 63 minutes (NTSC) / 75 minutes
(PAL)
Anatomy
of a CED Player
During an early demonstration of the CED system, Richard Sonnenfeldt, vice President of VideoDisc Operations described RCA’s approach to making a home video system as such - “Our philosophy is to put a simple, low-cost, easily serviced player in the home and to keep the space age technology in the factory.” The discs are pieces of precision manufacturing, but the machine that play them are simple devices, made from off-the-shelf components. A CED player is basically a modified record player. It has a needle that has to read grooves 32 times thinner than on a LP. But it doesn’t need to actually bury itself in the groove. It just has to glide within it above the bumps in the valley. Its these bumps that encode the video on the disc. All you need is some circuitry to turn those bumps into video. It’s a mechanically-simple machine. With fewer precision parts than a VCR, they were originally sold at half the price of them. RCA hoped that alone would convince customers to buy it over a VCR, which did more than just play pre-recorded content. A total of 750,000 CED players were ever made. 45 different models, all sold under 11 different brand names. RCA made most of them. 200,000 were made by other manufacturers – Hitachi, Sanyo and Toshiba. Early models (like the one been dissected here) were basic. In 1982 stereo sound was offered, with adaptors for previous models, and some gained a wireless remote control. In 1983 players offered random access, providing a true disc format experience. Interactive games could have made CED players game consoles, if they had been more successful. But, alas, the last CED player was made in 1984 and, soon afterward, became a footnote in home entertainment history.
Stylus
The keel-shaped diamond stylus has a titanium electrode layer. It rides in the grooves with light tracking force (65mg) to form an electric circuit. It only makes contact with the disc to touch the sides of the groove to stay in track. It isn’t made to wobble, like in a normal record player, because the actual information needed is the amount of air between the needle and the bottom of the groove.
Stylus Deflection
System
The stylus arm is surrounded by electromagnetic coils, which sense deflection. A circuit responds to these deflections by moving the stylus head carriage in steps as the groove pulls the stylus across the disc. Other coils deflect the stylus, to fine-tune tracking, especially when the user does a “picture search.” This system of coils, similar to that found in optical disc players, also ensures that the stylus’ drag angle is constant while in the groove, reducing tear. Also, these coils can detect when the stylus gets stuck in a groove and make an electromagnet bump the stylus out and move it a few grooves later.
Capacitors
A capacitor is an electronic component designed to store electric charge. Most capacitors are basically two metal plates separated by an insulator, such as air. In a CED player, the conductive plastic disc and the titanium coating on the stylus form a capacitor, with the air between them been the insulator.
Pictures
by playing with a radio tuner
Video and audio are encoded on the disc as vertical bumps in the bottom of the groove. As the stylus travels over them, the amount of air between the stylus and the conductive surface varies. This variation controls the capacitance between the stylus and the disc. This varying capacitance alters the frequency of a tuned circuit, like someone playing about with the tuner in a radio, which produces an FM electrical signal. This is then decoded as the video signal that is sent to the TV.
Video Resolution
CED has the same image resolution as VHS. Picture quality has been described as “very good, somewhat crisper than standard VHS and with very pure blacks.”
Easy
Maintenance
RCA estimated that, under ideal conditions, a CED could be played 500 times and a stylus can last for up to 1,000 hours of use. But it was advised that users change their stylus regularly to avoid damage. The stylus cartridge is easily accessible by a door on top of the device. The fact its there suggest that RCA expected users to go through many styluses.
Loading and Unloading Discs
Inside the caddy, the disc is surrounded by a removable “spine.” To place a disc in the player, the user has to insert the disc’s caddy fully into the front slot, until it stops. A mechanism then grabs the disc caddy’s “spine” and the user is made to pull out the caddy, leaving the spine and disc behind. The user inserts the caddy again to get the disc out. Later players had motorized loading mechanisms to make the process of loading and unloading discs gentler. But it did make the task of flipping a disc to the other side slower.
In early players, (like this one) the user had to manually move the spindle up after loading a disc by a function lever outside the player. This lever also closes a door over the caddy slot to prevent the loading of disc while in the “play” position.
A felt clutch here disengages when the function lever is set to “load,” freeing the carriage, making it possible for the user to push it back to the start while loading a disc. When the lever is set to “play” the clutch engages giving control of the cartridge back to the player.
When you press “stop,” (or in this model, select “Unload”) in a CED player the stylus is lifted off the disc and returns to its parking location. The spindle is moved down to free the disc and spine, ready for the insertion of the caddy.
An optical encoder is used here to monitor the carriage’s movement during “Rapid Access.”
Getting the video in sync
Syncing the video signals to the TV was a simple task in a CED player. The disc is rotated constantly with an AC motor, tying it to the frame rate of the TV. All the TV needs to do is detecting the vertical blanking intervals in the signal.
In early players, like this one, used a simple belt-driven AC motor to rotate the disc. Some later models used a quartz oscillator-controlled direct drive DC motor to allow more precise control of the disc for automated unloading.
Finding your Place
Pressing “pause” blanks the TV screen. Pressing it again (or a separate “play” button) resumes the video from where you paused it. “Visual Search” allows you to rewind/fast forward the video while still on the screen. This model can this 16 times faster than normal. “Rapid Access” (also called “Blanked Search”) allows you to rewind/fast forward even faster, by lifting the stylus off the record, allowing you to quickly move it to the desired section. This means that the screen is blank while doing so. Some later players didn’t have “Rapid Access,” but had a very fast “Visual Search” instead. “Page Mode” keeps the stylus in the same groove, playing the four frames stored there in a loop, in a pseudo-freeze frame. Not officially documented, this player has “Page Mode.” Its activated by pressing both “visual Search” buttons at the same time.
Early player only had a RF output. Later players, to allow stereo sound, had composite output as well as RF.s.”
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