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RCA SelectaVision VideoDisc FAQ


This page answers frequently asked questions about the RCA VideoDisc system. Each linked line below will take you directly to that particular question. If you are new to the Capacitance Electronic Disc system, I recommend reading this FAQ from start to finish as an introduction to the system.




From: (Tom Howe)
Subject: RCA SelectaVision VideoDisc FAQ
Followup-To: poster
Approved: news-answers-request@MIT.EDU
Summary: This posting answers questions about the SelectaVision VideoDisc System, a consumer video format marketed by RCA in the 1980's.

Archive-name: rec-video/videodisc/selectavision
Posting-Frequency: monthly
Version: 1.33

Copyright (c) 1996-2007 by Tom Howe. All rights reserved.

This FAQ may be freely redistributed in its entirety without modification provided that this copyright notice is not removed. It may not be sold for profit or incorporated in commercial documents (e.g., published for sale on CD-ROM, floppy disks, books, magazines, or other print form) without the prior written permission of the copyright holder. Permission is expressly granted for this document to be made available for file transfer from installations offering unrestricted anonymous file transfer on the Internet. If this FAQ is reproduced in off-line media (e.g., CD-ROM, print form, etc.), a complimentary copy should be sent to Tom Howe, P.O. Box 5604, Portland, Oregon 97228 USA.


RCA SelectaVision VideoDisc FAQ

This is a list of frequently asked questions regarding the RCA SelectaVision VideoDisc System, a delivery platform for home video marketed by RCA from March 1981 through June 1986. In the mid 1990's, defunct electronic technology from the 70's and 80's became collectible, as evidenced by the creation of Usenet news groups devoted to collecting items as diverse as 8-Track tapes and Atari 2600 video game cartridges. In this same time frame I was contacted by a number of people interested in getting more information on the RCA VideoDisc system, rather than to just sell their player and discs, and there were postings to the Usenet groups, rec.collecting, misc.wanted, and from people wanting to purchase discs. These events led me to start this FAQ, in part to provide answers to the increasing volume of questions regarding the SelectaVision VideoDisc system, and also to dispel some inaccuracies (such as the rumor that new stylus cartridges have been unobtainable for years). I saved all references to the RCA VideoDisc system that appeared in the above newsgroups since 1990, and it is from this data, as well as questions that have been asked of me by other collectors, that the questions in this FAQ are derived.




Why Collect RCA VideoDiscs?

I'm tackling this question first, since there have been several Usenet postings from people incredulous that anyone is interested in an obsolete video format that hasn't been supported in years. Well, my interest started in 1987 when I found a CED player (complete with Jane Fonda's Workout Challenge inside) for $10 at a thrift store. Being in an electronic engineering curriculum at the time, I got this to take apart and analyze how it worked. A while later I found a bunch of discs for 50 cents each, and became interested in getting as many different titles as possible. So my motivations have been an interest in the technology and the inexpensive nature of collecting it. Here are some reasons I've heard from other collectors:

American Technology- The CED system was envisioned and manufactured (all discs and the RCA players) entirely in the U.S.A., and it was the last major electronic entertainment format to have this distinction. It was also RCA's splashiest product introduction, and the last major thing the company did before its disposition by GE in 1986.

Nostalgia- Some collectors feel nostalgia for this system, since it was the first home video system that they owned movies for. This seems particularly true for young adults, who back in the early 80's had their very own stack of children's VideoDisc titles. (HINT: If you find children's titles in private collections, inspect them carefully- they may have been played to death).

Cool Design- Some collectors are captivated by the caddy design with automatic extraction of the disc (on the RCA J and K series, the caddy is slid 3/4 of the way into the entry door, whereupon a motorized mechanism takes in the caddy, unloads the disc, and ejects the empty caddy). I have CED and LaserDisc players adjacent to each other in my entertainment console, and am sometimes surprised that people unfamiliar with the CED format assume the CED player is newer than the LD player, even though it is 10 years older. They make this assumption purely on the basis of the "sophisticated" motorized disc extraction mechanism.

Needle Vision- Some people embrace the CED format for the very reason others have deplored it- the grooved, stylus-read media. CED represents the final chapter in grooved media that began with the Edison Cylinder in the 19th century. In an odd twist of history, LaserDisc and Audio CD were cool back in the early 1980's due to the newness of lasers in consumer products. But with the passage of time, the unusual capacitance pickup in the CED system has a retro appeal lacking in the commonplace laser pickups of today.

Unique program material- Although not as much a reason as a few years ago, there is still some CED material unavailable on VHS, LaserDisc, or DVD.


What does the acronym CED mean, and is there an explanation for how these discs work?

CED stands for Capacitance Electronic Disc, which refers to the method used to encode the video and audio information on the disc surface. Capacitance can be defined as the ability of two adjacent conductors to store electric charge, and in the CED system these adjacent conductors are the carbon-loaded disc and the thin titanium electrode deposited on the diamond stylus. The mathematical formula for capacitance contains several variables, but with the CED system these variables are all nearly constant except one-- the distance between the electrode and the surface of the disc immediately under it. Within the grooves on the disc surface are microscopic peaks and valleys, several times smaller than the diamond stylus, which rides smoothly on the crests of several adjacent peaks. But the electrode is much smaller than the stylus, so the distance between the electrode and disc surface is constantly changing as peaks and valleys pass underneath. This varying distance produces a varying capacitance, from which the audio/video signals are eventually decoded by the player's signal processing circuitry.


What are the technical specifications of the RCA VideoDisc system?

Here are the technical specifications for the RCA VideoDisc System, derived from various sources:


What is the proper terminology to use when talking about RCA VideoDiscs?

The name used by RCA for the first couple of years of production was "RCA SelectaVision VideoDiscs" which was later abbreviated to "RCA VideoDiscs." Collectors usually call them CED's amongst themselves. The name "Capacitance Electronic Discs" is not commonly used, and "CED VideoDiscs" is actually redundant, although that terminology was used on RCA/Columbia titles and on the PAL/UK system discs. I've had the most success with want ads in newspapers and other venues with the name "RCA VideoDiscs." The word SelectaVision is often associated exclusively with RCA VideoDiscs, but the term actually originated in 1969 and applied to all three of RCA's home video player research projects (Holotape, Magtape, and VideoDisc), and ultimately was used for RCA's VHS videocassette recorders (technology purchased from Matsushita rather than being developed internally at RCA).


Where can I find RCA VideoDiscs and players?

The best retail establishments, in order of preference, are thrift stores, used record stores, and pawn shops. But don't assume you can walk into your local Goodwill and find CED stuff, since in my experience (at least recently), the discs and players, if reasonably priced, are purchased within a few days of being put out on the sales floor.

With used record stores, a useful technique I have found is to carry a CED into the store and ask the proprietors if they have any of these "things." A lot of times when trying to verbally describe a CED it's evident they don't have a clue as to what you're talking about. Sometimes used record stores have CED's tucked away in boxes or under bins where you wouldn't find them, even if you thoroughly searched the store.

Pawn shops used to be a good source for CED's, but most pawn shops will no longer buy the discs, although on occasion they still turn up. CED's also turn up occasionally in yard and estate sales, and at swap meets and ham radio fests.

I believe the single best local source for CED's, particularly if you live in a metropolitan area, is an "RCA VideoDiscs Wanted" ad in the local newspaper or nickel ads. I have run such ads in a number of newspapers around the country and have always gotten quite a few responses from people with a stack of CED's and a player in their closet, attic, or basement. What often happens when I go to look at these, is the player no longer works, even though it did when they stored it away. So they are usually willing to sell the whole bundle for a low price.

Another source for CED's that has emerged with the expansion of the WEB is the eBay Auction Site at this URL:

It seems that at any given time CED's or players can be found at auction here, so it's a good place to both buy and sell CED items. The site can be navigated two ways. One way is to browse the listings. CED's will appear in a number of categories, but most commonly appear in:

Movies & Television: Video, Film: Other Formats

CED players most frequently appear in the above category as well as:

Electronics & Computers: Home Electronics: Vintage

The other way to find CED's at eBay is to use their search engine, which looks for matching terms in the auction title and/or description. Try case-insensitive terms like videodisc, video disc, ced, selectavision, and even misspellings like videodisk. In general, sellers of CED's get more at eBay if they list each title individually.


Are there any mail-order CED dealers still in operation?

There were quite a few CED dealers back in the late 1980's, but I am aware of only two that are still active:

MailBox Video
19050 Middlebelt Rd.
Livonia, MI 48152
(248) 442-9360

This company deals in CED and other video formats, and currently has a listing of a number of CED's for $5 or less per title (they also have periodic sales). They have multiple copies of many of their titles, and will trade 2 for 1 on titles they don't have. All the titles come shrink-wrapped, usually with a $29.95 price tag, but this is rarely the original factory shrink-wrap, since on most discs you can see marks on the caddy underneath the shrink wrap, and some discs, on inspection, reveal fingerprints. Still, the quality of their discs is roughly on par with discs I have gotten from private collections.

PDQ Records
2342 North Dodge
Tucson, AZ 85716
(520) 881-2681

A giant used record store that also carries a large stock of CED's. They have a web page at the above URL, where you can fill out a form requesting CED titles.


Is there a site on the World Wide Web where I can get information on the RCA VideoDisc system?

I have established a web site named CED Magic for information on the CED system, which is located at the following URL:

This site currently has this FAQ, databases of both NTSC and PAL CED titles with rarity ratings, a classified ad section, pictorials on player and disc manufacturing, reference guides on CED players, stylus cartridges, and drive belts; along with some QuickTime movies and audio files, links to related web sites, and an expanding technical reference area. It also has a section on the history of media technology and a memories section related to RCA VideoDisc. I will be uploading further reference information on the CED system as I get it prepared.

Also available for purchase at this web site is an RCA VideoDisc Collector's Guide CD-ROM, which contains the web site info plus about 600MB of additional data comprised of high resolution photos of over 1,700 VideoDisc titles. There is also a discussion forum at the following URL:

Complementing the discussion forum is a weekly mailing called CED Digest that contains all the postings to the forum for the past week, as well as a weekly column titled "20 Years Ago in CED History" detailing CED news and title releases and other major news and pop culture events exactly 20 years ago.


In what countries was the RCA VideoDisc system available?

The RCA VideoDisc system was primarily a US/Canada product and was also marketed for a while in the United Kingdom and Australia. The system was never marketed in Japan, although a number of players were manufactured there.


Is the RCA VideoDisc system older than the MCA DiscoVision reflective optical disc system (later called LaserDisc)?

The MCA DiscoVision system was first offered for sale on December 15, 1978 when a small quantity of discs and players were made available (and sold out) in Atlanta, Georgia. So the public availability of DiscoVision predates CED by over two years. Many people have the perception that CED is older because of field testing RCA began in 1975, and extensive press coverage in 1976 and 1977 that suggested the CED system was nearly ready for market introduction. And LaserDisc did not achieve a nationwide market until about the same time CED was introduced.


The music played at startup on the early RCA VideoDiscs from 1981 sounds familiar. Where have I heard it before?

This music is from the Promenade of Modest Petrovich Mussorgsky's "Pictures at an Exhibition." The electronic version heard on the 1981-released VideoDiscs is Isao Tomita's rendition of this work, recorded in 1974. The Tomita rendition was once available in stereo LP, quadradisc, and 8-Track (stereo and quadraphonic), and is still available on an RCA Victor Dolby Surround CD, stock no. 60576-2-RG. The Mussorgsky music was replaced on VideoDiscs released in 1982.


What does the phrase "Nipper's Revenge" mean in regards to the RCA VideoDisc system?

Nipper is the dog in the familiar RCA trademark where the terrier mutt peers attentively into the brass horn of a gramophone waiting to hear "His Master's Voice." This actually originated in an 1895 oil painting, and became a registered trademark in 1900, sometime later being acquired by RCA. The trademark fell into disuse in 1968 when Robert Sarnoff (son of RCA founder David Sarnoff) became CEO and instituted the red acrylic systems logo (still in use today in different colors). But Nipper came back when Edgar Griffiths became head of RCA, later appearing on the nameplate of the SFT100 VideoDisc player, and appearing on all the disc caddies during the first year of production. Thus "Nipper's Revenge" refers to his comeback in a "needle" based unit similar to the original gramophone. And even though corporate RCA no longer exists, Nipper and his young sidekick Chipper are still popular trademarks today.


How does the resolution of CED compare to the VHS, LaserDisc, and DVD video formats?

RCA didn't use Lines of Resolution in their CED specifications, but a bandwidth of 3 MHz translates to about 240 Lines, the same resolution as VHS, but less than the 425 Lines of LaserDisc and 500 Lines of DVD. The subjective evaluation of people familiar with all these formats is that CED is better than VHS, but not as good as LaserDisc or DVD. CED does pale in comparison to modern LaserDisc and DVD players, but in 1981 there wasn't a lot of difference, because LaserDisc technology was young, and at that time RCA had superior mastering techniques. A comparative review of the Zenith VP2000 CED player and the Magnavox VH8000 LaserDisc player in the July '81 issue of Popular Electronics rated the Zenith unit better in Video and Audio Signal-to-Noise ratios, but lower in total Video bandwidth.


Magazine articles in late 1976 and early 1977 implied the imminent release of the RCA VideoDisc system. Why didn't it appear until March 1981?

In late 1975, Anthony Conrad replaced Robert Sarnoff as head of RCA and decided to proceed with market introduction of the CED system. One notable article in the February 1977 issue of Popular Science was illustrated with a photo of the Indianapolis plant, showing many of RCA's top-loading CED players under assembly. This article implied a 1977 introduction of the system, but it was actually in limbo with Conrad having been ousted as CEO in late 1976 in the wake of income tax improprieties. He was replaced by Edgar Griffiths, who at that time was an opponent of the VideoDisc system. Griffiths scaled back the VideoDisc program, shutting down the Indianapolis pilot production facility in July 1977, but allowed basic VideoDisc research to continue. This situation continued until January 1979, when he abruptly announced that RCA would rush VideoDisc to market (it became known as RCA's Manhattan Project). The speculated reason for this about face is that the decision was made in response to a cover article in the December 31, 1978 issue of Fortune, that although mostly favorable, portrayed Griffiths as being overly cautious in his approach to technology-based products like VideoDisc.

From the perspective of VideoDisc collectors, it's probably favorable that the introduction of the CED system was delayed. The 1977 version of the CED was limited to 30 minutes per side, and used a 3-layer design, consisting of a metallized vinyl disc, with a layer of polystyrene on top. RCA had problems with adhesion, corrosion, and stylus damage using this "sandwich" construction of dissimilar materials, so this design in reality was not ready for market introduction. The delay afforded RCA engineers the opportunity to develop the diamond stylus, whose smaller dimensions allowed nearly doubling the groove density to 9,541 grooves/inch. They also developed the carbon-loaded PVC disc, which eliminated the need for the 3-layer construction. In addition, the decision was made to house the discs in protective caddies, which in large measure is why the discs are still usually found in good condition today.


Grooved records containing images and sounds of Earth were placed on the two NASA Voyager spacecraft launched in 1977. Were these CED's?

The Voyager Interstellar Records were not CED's but gold-plated Audio LP mothers made of copper, which normally would be used to make stamping molds for vinyl LP's. The records were specially mastered to spin at just 16 2/3 RPM and needed several seconds to play back each still image. Playback directions and a stylus cartridge were included with the records. RCA was involved with the production of the Voyager records, and the image reconstruction uses multiple scan lines similar to television.


Who were some of the key people involved in bringing the CED system from research concept to a manufacturable product?

Thomas Stanley of RCA Laboratories suggested in 1959 that video could be stored capacitively on a vinyl disc if a means could be found to mold sufficiently small signal elements in the surface of the vinyl. Formal research on this concept began at RCA Labs in 1964, and really took off when the team of Jon Clemens and Eugene Keizer was put together shortly thereafter. Dr. Clemens was a recent graduate of MIT and was deeply involved with getting CED to market and can rightly be called "the father of the CED." He applied for U.S. Patent No. 3,842,194 on March 22, 1971, which is the primordial CED patent, as hundreds of those that followed reference it.

Richard Sonnenfeldt was Vice President in charge of VideoDisc during the development phase from 1974 to 1978. Jay Brandinger was VideoDisc Vice President during the push to market phase from 1979 to 1981 as well as the market phase from 1981 through 1984. There were some 2,000 RCA employees involved with CED during its development and time on the market, many of whom are covered in the "Memories of VideoDisc" section at the CED Magic web site:

The 1981 David Sarnoff Awards for Outstanding Technical Achievement were awarded to the nine scientists and engineers who RCA felt contributed the most to getting CED on the market. Here's a brief summary:

Todd Christopher - for player electronics and signal encoding standards.
Jon Clemens - as the key architect of the CED system as a whole.
Pabitra Datta - for developing the carbon filler of the conductive disc.
Leonard Fox - for conceiving and championing the conductive disc concept.
Jerome Halter - for the development of electromechanical cutterheads.
Eugene Keizer - for major contributions to mastering and stylus design.
Marvin Leedom - for mechanical design including the caddy concept.
Michael Miller - for the stylus cartridge and associated mechanisms.
Fred Stave - for the disc/caddy interface and other mechanical concepts.


Why did the CED system fail to even come close to RCA's expected market penetration?

RCA expected to sell 200,000 players in 1981 (they sold half that number), and the company forecast that in 10 years the players would be in 30 to 50% of all American households with $7.5 billion in annual sales of players and disc. Why didn't this happen? The simple answer is competition from another video delivery platform- the VCR. RCA's estimate of the success of the CED system may have been accurate, perhaps even conservative, if there had never been a video cassette recorder. When the CED system hit the market, VCR's were well established, and the typical consumer thought "Why would I want this VideoDisc player, when for about the same price I can get a VCR that both plays and records." RCA's market research didn't take videocassette rental into account at all, and a lot of consumers who earlier would have been willing to purchase movies now preferred to rent them.

If not for the media problems, RCA could have released the CED system regionally in 1977 when it probably would have been more successful. At that time VCR's would have been double the price, prerecorded tapes and rental outlets were rare, and blank tapes were just a little less than the anticipated price of a VideoDisc. The RCA VideoDisc system was a technological success, increasing the data density of an audio LP by over two orders of magnitude, but it simply reached the market too late.


Why did RCA abandon further development of the CED system in April 1984?

At the end of 1983, RCA had sold fewer than 500,000 players total, when by earlier estimates they should have sold more than that in 1983 alone. They had also cut the price of the players on more than one occasion, and offered rebates, which assured that player manufacture would be operating in the red for several more years. The VCR was even more entrenched as the video delivery platform of choice, so it simply made economic sense to cease player manufacture. Disc manufacture was actually successful, since consumers were purchasing about twice as many discs annually as RCA had projected. This may have been the main reason RCA promised to continue disc production for an estimated 3 years after player manufacture ceased.

The decision to discontinue the CED system was not attributable to a new chief executive at RCA, since Thornton Bradshaw was still in charge of RCA, as he had been for nearly the entire CED era. He was chosen to lead RCA in April 1981, just one month after the introduction of the CED system, and officially replaced Edgar Griffiths on July 1, 1981.


How much did CED players and software titles cost when they were new?

RCA priced some of their players at $499.95 when first introduced-- this was the retail price of the SFT100 in March 1981 and the SJT400 in October 1983. The SGT250 was introduced in May 1982 at a price of $399.95, at which time RCA reduced the remaining stock of SFT100 players to $299.95. After RCA canceled player production prices began to plummet. A brochure from October 1984 lists these prices:

SJT090 at $149, SJT100 at $159, SJT200 at $169, SJT300 at $229, and SKT400 at $249.

CED disc titles commonly retailed from $14.98 to $39.98. The $14.98 price was rare and used only for some cartoons, sports, and documentaries. Movies ranged from $19.98 to $34.98 for 1-disc titles, and $34.98 to $39.98 for 2-disc titles. The 4-disc "Jesus of Nazareth" boxed set was originally priced at $99.98. One 2-disc title, "Conan the Barbarian," was priced at $44.98, but the backlash from customers and dealers resulted in this being the only title released at that price.




Who manufactured CED Players, and how many different models are there?

There were 4 manufacturers, marketed under eleven brand names, with a total of 45 different player models. The Elmo, GEC, JC Penney, Realistic, Sears, Wards, and Zenith name brand models were electrical and mechanical clones of models distributed by the four manufacturers. There were also stereo adapters manufactured for the Hitachi VIP1000 and Toshiba VP100, and a planned, but unreleased stereo adapter for the Sanyo VDR3000. Pictures and specifications on all CED players are available in the CED Player Reference Guide.


How many CED players were manufactured over what time span?

Players were manufactured from late 1980 (in preparation for the Spring 1981 introduction of the CED system) until shortly after RCA's abandonment of the system in April 1984. A total of about 750,000 CED players were made (550,000 units from RCA and 200,000 units from all other manufacturers).


What are some recommended CED player models?

There are two models I'd recommend any serious CED collector to seek out, the RCA SGT250 and SJT400 (or the much rarer SKT400). Once you've gotten used to the 400 series players, it's hard to return to any of the earlier models that lack a multi-function remote control. The random access SJT400 uses an IR remote that permits numerous user control functions such as time seek, band seek, programmed time play, programmed band play, and program repeat. In addition, it allows the player to be placed in page mode, the CED equivalent of freeze-frame, except the same four video frames are shown repeatedly. In page mode the displayed image may or may not be jittery, depending on the rate of motion in the original scene. It is also possible to simulate slow motion while in page mode by repeatedly pressing the NEXT key to advance the stylus over the disc groove-by-groove. A 400 series player is required to play the Interactive VideoDiscs in random access mode, although these discs can be played straight-through on any CED player, but usually with nonsensical results.

I recommend the SGT250 because it was the last RCA player model to use the original-style stylus cartridge. In the years to come these stylus cartridges will probably be more readily available, for the simple reason that most everyone collecting CED discs is using a J or K series player. This player is sort of a cross between the G and J lines in that it has the chassis of the G line but the electronic "soft-touch" operation of the J line. This model also uses a simplified IR remote permitting rapid forward/reverse, visual search forward/reverse, and pause. Internally, this unit has the most solid construction of any player model I have seen.

If I was going to recommend against any player models, it would be the Hitachi manufactured units and their name-brand equivalents. This is because the Hitachi-style stylus cartridges are already difficult to find, and will only become more so.


The RCA K series players appear externally identical to their J series counterparts. What changes were made in the K series?

Although at first glance identical, minor cosmetic changes were made with the K series on the front panel, buttons, and remote control. In addition, some refinements were made to the circuit design, resulting in some component value changes, additions, or removals. When servicing these units, it's necessary to use the service manual specific to that particular J or K series model.


Do any CED players have a serial port to control the player with an external computer?

RCA made four models controllable with an external computer- the SKT265, SJT400, SJT400X, and SKT400. The SKT265 was intended only for institutional use, as the additional circuitry was mounted on an external circuit board wired to the unit with a ribbon cable. On the back of the SKT265 was a 15 pin serial port similar to those used on computer-controllable LaserDisc players.

The SJT400 and SKT400 players had an RCA-style jack in the back simply labeled "Control" that could be used with an external computer. RCA was deliberately vague on the purpose of this jack, stating in the owner's manual that the jack was for "connection with accessory equipment that may become available in the future," and making no definition of it at all in the technical and service manuals. By disassembling the player, and tracing the control jack's lead to J6107 on the FEATURES/RKM/CAV board, the circuitry associated with the control jack can be assessed from the player's schematic. The control jack lead connects to the remote keyboard microcomputer through a receiver/driver transistor network, meaning the jack can both transmit and receive data over a single piece of wire. The external computer has to transmit its data in a handshaking protocol the remote keyboard microcomputer can understand. The control jack was used in the short-lived Bally NFL Football Arcade Game to display live action from a VideoDisc. And in addition, an interface to attach the 400 series player to the ColecoVision video game system and ADAM home computer was planned, but RCA's abandonment of the CED system halted this project in the prototype stage.

The control jack reappeared in RCA's Dimensia system in late 1984 as the common method for all the individual audio/video components to communicate with one another. RCA's prototype SKT425 player was going to be an integral part of Dimensia, but since this was after the cancellation of CED, RCA made no mention of this in any of the Dimensia announcements or literature. But the control circuitry is still fully compatible, so any 400 series player can be added to the Dimensia control bus.


Is it true that new stylus cartridges for CED players have been unavailable for a long time?

This rumor may have started when the Q & A Column in the January 1994 issue of _Video Magazine_ answered a reader's inquiry by stating RCA had "...exhausted its stock of replacement styluses some time ago." Well, a call to the GE/RCA Parts Department at the time revealed they still had a total of about 8,000 stylus cartridges in inventory. This RCA Parts Department no longer exists but all three stylus cartridge models are available via the Internet. Cartridges for the Hitachi models are difficult to come by, with some owners buying complete, working players on eBay just to get the stylus cartridge. Note that the manufacture of CED stylus cartridges ceased shortly after CED player manufacture came to a halt in 1984, and RCA only had a single keel-lapping master recorder from which all the masters used to shape diamond styli originated. If this complex machine has been dismantled, the technology required to manufacture these diamond styli no longer exists. The Stylus Cartridge Replacement Guide cross references the cartridge part numbers for the various CED player name brands. This guide also provides some web links for locating CED stylus cartridges.


Are the stylus cartridges used in stereophonic players different from those used in monaural players?

RCA introduced a new stylus cartridge about the same time the stereo players hit the market. This new cartridge was intended for use with a redesigned stylus sensor mechanism. All F and G players with the older pickup arm assembly No. 149002 should use the No. 149000 stylus cartridge, while players with the newer pickup arm assembly No. 154036 should use the No. 154100 stylus cartridge. Here's a stylus cartridge replacement summary for all RCA players:

Stock No. 149000 used in all SFT100
Stock No. 149000 used in early SGT075 and SGT100
Stock No. 154100 used in SGT075 and SGT100 starting with Serial No. 2155xxxxx
Stock No. 154100 used in all SGT200 and SGT250
Stock No. 154216 used in all J and K series players

It is still always possible to use the 149000 cartridge in place of the 154100 cartridge, but using the 154100 in a player designed for the 149000 may possibly cause problems. With the new pickup arm assembly, RCA widened the stylus sensor spacing to accommodate a rubber damper that can be seen on the 154100 cartridge just above and behind the stylus tip. This rubber damper lessens the likelihood of audio resonance which can sometimes be heard as a hissing sound around 10 KHz. A 149000 cartridge can be used with this new arm assembly with no ill effects other than the resonance damping function not working. But using a 154100 cartridge in a player with the narrower stylus sensor spacing may cause the visual search mechanism to fail in either the forward or reverse direction. This would occur on 154100 cartridges that have the rubber damper uncentered, leaving too little space for the magnetic coil to kick the stylus the required two grooves forward or two grooves back.

The 149000 is also the preferred replacement in the monaural Elmo, Sanyo, early Sears, Toshiba, Wards, and Zenith players that are either internally identical to the SFT100, or were designed before RCA implemented their wider stylus sensor spacing. Hitachi and Toshiba also manufactured their later stylus cartridges with a rubber damper, but these dampers were narrower than RCA's, and didn't require a widened stylus sensor mechanism.


How long should a new stylus cartridge last?

RCA tests indicate an expected life of about 1,000 hours play time for the diamond stylus cartridge. Some early reviews of the CED system stated 200 hours of play time, but this was for the sapphire stylus, which was never used in a production player. There are a couple of conditions to watch out for that can result in immediate failure of the stylus cartridge. One is the attempt to play a cracked disc, since the crack can rip the stylus arm right out of the cartridge. To avoid this, I always inspect my discs for damage when I first get them. The other condition is a static discharge between the stylus and disc surface that can actually destroy the conductivity of the titanium electrode on the trailing edge of the diamond tip. This is a rather unlikely occurrence, but can happen with some players if the grounding spring near the top center of the turntable is broken or missing.


How do I install a replacement stylus cartridge in my CED player?

On all players except the RCA J and K series, there is an access panel on top of the player. With the power off and no disc loaded, remove this panel, then open the stylus cartridge retaining lid on the pickup arm itself, and the cartridge will be visible. The cartridge is locked in place only when the retaining lid is closed, so with that lid open, the cartridge lifts straight up without resistance.

On the RCA J and K series players, the player cabinet top must be removed to access the cartridge. Remove the two screws at the back of the player, lift the rear of the cabinet top up, and separate it from the player. With no disc loaded, and the player unplugged, locate the second reduction gear near the front right inside the player (a picture inside the cover illustrates the second reduction gear). By rotating this gear to the rear of the player with your thumb, the pickup arm will also move to the rear. Move the pickup arm far enough to the rear so the stylus cartridge access lid can be raised unimpeded. The access lid is held closed by a latch spring that can be freed with a small blade screwdriver. On these players, the stylus cartridge is held in place by a spring-loaded mechanism. Using thumb and forefinger, grasp the stylus cartridge and push it slightly to the right against the spring pressure, then tilt the left end of the cartridge up and remove it from the player. After the new cartridge is installed and the access lid is closed, replace the cabinet top. The best way to replace the cabinet top is to hold it at a 15 degree angle and align it along the front edge before lowering the rear into the closed position. The pickup arm will automatically return to the home position the next time the player is powered up.


My CED player is broken, and none of the service centers in my area will work on CED players. What can I do?

Well, the simplest solution might be to run an "RCA VideoDisc Player Wanted" advertisement in your local newspaper or nickel ads, then put the broken player in storage as a possible source for spare parts later on. Fully 90% of the player failures I've seen are attributable to worn out stylus cartridges or failed rubber belts, and many of the remaining 10% are due to broken or misaligned levers and gears. These are repairs almost any competent VCR technician could handle, but they would rarely have a working stylus cartridge to first eliminate that as the source of failure. The Related Sites page provides additional information on obtaining CED player repair.

Sometimes a failed stylus cartridge can be identified by visual inspection, and it is sometimes possible to identify this problem by loading a disc into the player and listening carefully as it attempts to enter the play mode. If a faint repetitious clicking sound is heard, this would indicate a worn out stylus. That sound is actually produced by the stylus lifter mechanism lowering the stylus into the grooves, failing to get a signal lock, lifting the stylus, then repeating the sequence.

A stylus cartridge may simply needs cleaning to become functional again. All CED players use a stylus sweeper mechanism, which is basically a felt pad the stylus is drawn over every time a disc is loaded into the player. If this mechanism is broken or worn out, gunk will accumulate on the stylus tip. I have used a very thin #0 insect mounting pin to carefully scrap this off, and these cleanings have to be repeated periodically unless the stylus sweeper mechanism is repaired. The RCA 300 and 400 series players have an additional stylus sweeper built right into the pickup arm. This mechanism is activated each time the player is put in pause, or whenever the player encounters carrier distress 3 seconds in duration (usually due to a piece of dust caught on the stylus tip).


Will it be impossible to find replacement electronic components for CED players, when these are no longer available from the original manufacturer?

Actually, looking 20 years into the future, CED players will be easier to service than, for example, a DVD player purchased new today. This is because CED players were manufactured in the era when consumer electronics used mostly off the shelf components, and the "through board" mounting of components, which facilitates replacement of individual components with little more than a soldering iron. Most of the capacitors, inductors, resistors, diodes, and transistors used in CED players can still be purchased at your local Radio Shack, and even the integrated circuits were industry standard parts when possible. The exceptions are the microcomputer IC's, and a few IC's specific to VideoDisc signal processing. Even with these IC's, the chips can often be scavenged from broken players set aside as parts machines. For example, the same CMOS DAXI Buffer (an IC that transmits digital auxiliary information recovered from the disc to the system control microcomputer) was used in all RCA players from the SFT100 through the SKT400.

Contrast this to modern consumer electronics, which have application specific integrated circuits throughout and employ multiple layer boards with surface mount technology. These innovations have resulted in reduced cost, size, and power consumption, but have made circuit level repair very difficult. The standard repair practice nowadays is to replace the whole circuit board, or simply dispose of the entire unit.

I have prepared three documents to facilitate replacing defective IC's, diodes, and transistors in RCA players-- RCA Player Integrated Circuits by Player Model Number, the RCA Player Integrated Circuits Reference Guide, and the RCA Player Diode and Transistor Reference Guide. Another document, CED Player Parts Sources provides links and phone numbers for a number of OEM and generic parts suppliers.


Why does my CED player eject the disc caddy without removing the disc?

This condition occurs on the RCA J and K series players when the function motor belt is nearly worn out. Sometimes the life of the belt can be extended by using your fingers to push the caddy all the way in until it latches, but the problem in doing this is that when the function motor reverses direction to return the empty caddy, the loose belt may not allow it to eject. Then a small needle nose pliers is required to grasp the corner of the caddy and pull it out.

A better solution is to replace the function motor drive belt which costs about a dollar and takes about 5 minutes. The replacement belt is PRB No. SCB3.6, available at most electronic repair shops. I have prepared a CED Player Belt Replacement Guide that cross references CED timing and drive belts to the available PRB equivalent, and also provides links to several companies that sell belts.


Why do the side indicator LED's on my player indicate the wrong side on some of my discs?

The status of the side indicator LED's is determined by switches inside the player that are turned on or off by the disc spine. So someone removed the disc from the caddy and reversed its orientation when putting it back in. To correct this problem simply remove the disc from the caddy (another question in this FAQ specifically tells how), turn the disc (but not the spine) around, and put it back in. For ease of identification, the sides of all VideoDisc spines are labeled Side 1 and Side 2.


Where can I get a service manual for my CED Player?

Photocopies of the service manuals for the RCA and Sears players, as well as the Hitachi VIP2000 are available from Sams Technical Publishing at (800) 428-7267. To order, just supply the name brand and model number of the player. Service manuals for PAL-format GEC and Hitachi players sold in the United Kingdom may be obtained from Mauritron Technical Services at 01844-351694. For other CED players the service manual can sometimes be obtained from the service department of the name brand that appears on the player. Note that it is not always necessary to get the original manual. For example, the manual for the Sears 934.54780150 can be used for the Realistic 16-301, since these two players are electronically and mechanically nearly identical. Both Hitachi and Toshiba have almost totally abandoned their service support for CED players, so it is may be easier to obtain parts from the service departments of their name brand equivalents. Consult the CED Player Reference Guide to determine these equivalents.


Can separate Audio/Video connectors be added to my CED player that does not have these built-in?

With many CED players it is possible to add these connections, in fact, you may come across a CED player with auxiliary connectors already installed. But before installing these, note the following warning from RCA's service literature:

"DESIGN ALTERATION WARNING-- Do not alter or add to the mechanical or electrical design of this VideoDisc Player. Design alterations and additions, including, but not limited to, circuit modifications and the addition of items such as auxiliary audio and/or video output connections, cables, and accessories etc. might alter the safety characteristics of this VideoDisc Player and create a hazard to the user. Any design alterations or additions may void the manufacturer's warranty and may make you, the servicer responsible for personal injury or property damage resulting therefrom."

With the above disclaimer noted, it is still possible for a knowledgeable electronics technician in possession of the player's service manual to perform a safe installation.

A/V output jacks can be added to the RCA SFT100, SGT075, SGT100, SGT101, SJT090, SJT100, SJT101, SKT090, SKT100, and Zenith VP2000, which, if well shielded, will markedly improve the quality of the audio and video sent to the television monitor itself equipped with separate A/V input jacks. All other CED player models came from the manufacturer with separate A/V jacks already installed. RCA provided audio and composite video test points on the signal processing board to which a set of external A/V jacks can be connected with a length of shielded wire. The audio and composite video test points are, respectively, TP3601 and TP3409 on the F, G, and Zenith players, and TP3504 and TP3410 on the J and K players. On the actual circuit boards inside the players, these test points are labeled TP601, TP409, TP04, and TP10, since it is standard practice to drop identical leading digits when labeling a related section of circuit board. After installation, it may be necessary to adjust the screw on the video level resistor R3202 to get a balanced image, and the original RF and added A/V outputs should not be used simultaneously.


How can I program a universal IR remote to control my SGT250 player?

The SGT250 (as well as the SJT300, SKT300, and JCPenney 685-5705) used an analog infrared remote whose signal was decoded on the basis of its frequency. Most universal remotes use digital infrared signals, which these models of CED players can't decode. So even if you have a trainable universal remote, it still won't be able to understand the signals from the VideoDisc remote. For a while in the mid 1990s RadioShack sold some Six-in-One remotes that had a digital equivalent of the simple analog coding necessary to control the SGT250/SJT300 players. Because these Six-in-One remotes also have a JP1 interface, it is possible to extract the coding and transfer it to modern remotes. More information on this is available in the Technical Information section at CED Magic:

In contrast, the SJT400 and SKT400 players use remotes that were among the first devices to conform to the current digital IR standard, so the functions of these remotes can be programmed into a trainable remote. The RCA Digital Command Center was an alternative remote available for the 400 series players that was also capable of controlling RCA TV's and VCR's conforming to the digital IR standard. Thomson Consumer Electronics hasn't changed the code mapping on the RCA TV's and VCR's they currently manufacture, so the 1983 Digital Command Center can still be used to control these devices. There is also a program available for download at the CED Magic web site that permits a Palm Organizer to be used as a 400 series player remote.


Can I remove RCA VideoDiscs from their caddies and play them in my LaserDisc player?

The answer to this question is an emphatic NO, but I'm surprised at the number of people who have attempted this. It seems that people think the CED disc will play, since it's about the same size and fits inside the LaserDisc player. But the two systems are completely incompatible with each other, so it likewise isn't possible to put a LaserDisc inside a CED caddy and play it on a CED player. Attempting this will abrade the surface of the LaserDisc, and probably get it stuck inside the CED player.


I've heard there are special LaserDisc players that can play CED's. Where can I get such a player?

I wouldn't call these LaserDisc players, but RCA had a number of laser-based optical readout devices in their plant that were used in conjunction with VideoDiscs. The purpose of these machines was to perform contact-free playback and high-speed optical measurement of masters, stampers, and sample discs. The copper masters were quite reflective, so RCA was able to use an optical readout station to verify they were defect free before making the inverse-replica stampers. High speed defect detectors were also available to scan about 100 grooves at a time for defects. None of these units were designed or intended for consumer use, since they were costly to construct, and the smallest of them was the size of a kitchen range. The entire September 1978 issue of the technical journal _RCA Review_ is devoted to the topic of VideoDisc optics.


I've heard of a CED player called the VHD system that doesn't use grooved discs. What is this?

The Video High Density system - a joint effort by Matsushita and JVC, was intended to be introduced shortly after the RCA VideoDisc system. RCA was somewhat chagrined in 1977, when after demonstrating the RCA VideoDisc system to a group of JVC technical experts, JVC provided a counter demonstration of their until-then unknown VHD system. The system uses a 10" grooveless disc stored in a caddy like the RCA system (VHD is incompatible with the RCA VideoDisc system). A rather wide diamond stylus tracks the disc surface with a servo mechanism reading tracking signals adjacent to the capacitance-encoded signal pits on the disc surface. Because the stylus force is spread over several adjacent signal channels, estimated disc life is longer than RCA's system- about 10,000 plays per disc. A $12-million factory was built in Irvine, California to press the discs, but the system was never marketed in the U.S. The VHD system was marketed in Japan starting in April 1983, and the system was launched in Great Britain by THORN EMI in January 1984, targeted at the industrial market.


I have a different-looking caddy labeled Thomson-CSF with a 12" disc inside. Is this a new version of the CED system?

This is a disc used in the Thomson transmissive optical disc system, a contemporary of the RCA VideoDisc system targeted to a limited degree at the industrial marketplace in the early 1980's. This system is no longer supported, and it is mere coincidence that Thomson presently owns RCA's Consumer Electronics Division. This system had the then distinct feature of having two levels of pits which the laser could track simply by refocusing itself. So unlike the DiscoVision system in the early 80's, both "sides" of a Thomson-CSF disc could be played without flipping the disc over. The system was quite sensitive to dust and fingerprints, hence the caddy-housed discs.




How many different CED's were pressed?

I have personally seen a little over 1,700 NTSC CED titles, which is close to the total number. There also appear to be a fair number of CED Vaporware Titles, i.e. titles that were listed in publications as available or soon to be available for the CED system, but which in fact were never released. There were about 270 PAL/UK titles released on CED in Great Britain.


Which CED titles are rare and/or collectible?

In general, CED titles released after RCA announced their abandonment of the CED System in April 1984 are less common than those released earlier. After the announcement, most consumers quit buying the discs altogether and most retail establishments closed out their inventories, leaving mail order and rental as the main venues for new releases. With the passage of time demand for the discs continued to decrease until disc pressing ceased entirely in 1986. Only a couple dozen titles have a packaging copyright date of 1986, and only two movies copyrighted 1986 are on CED: "Black Moon Rising" and "Youngblood."

An example of a highly collectible title is "Return of the Jedi." There are several reasons for this:


Is there a listing of all CED titles with a rarity rating for each title?

I have prepared a CED Title Database, that lists approximately 1,700 titles, and provides additional information like the universal product code and sound format for each title. The CED Title Database also includes a rarity rating for each title ranging from common down through uncommon, rare, very rare, and extremely rare. The rarity ratings were derived from a statistical analysis of some data I accumulated over several years of CED collecting.


Was the same movie ever released twice in the CED format?

I know of about sixty NTSC movie titles released twice in the CED format. Usually, these are titles originally issued by RCA, and later reissued by CBS with different caddy artwork. A few of them are titles issued twice by RCA, first with monaural sound, and later with stereo sound. In all these instances the reissue was given a new universal product code.


What is the significance of the white, blue, and black colors of the caddies VideoDiscs come in?

The color of the caddy often indicates some information about the disc inside. White caddies are the most common, and usually indicate a monophonic, non-interactive disc, but some of the later stereo and dual soundtrack releases came in white caddies, and some of these releases appeared in both white and blue caddies. Blue caddies indicate the disc is recorded in stereo sound or indicate the disc is a dual soundtrack (A/B) title. Black caddies are far less common than white and blue, and were intended to indicate an interactive disc, although Disney released their seven "limited gold edition" titles in black caddies. Black caddies were also used on some discs not intended for public dissemination, such as RCA test pressings and dealer demonstration titles. Some gray caddies also exist, but these are so rare that most collectors have never seen one. RCA intended to use gray caddies for their industrial training disc program, but this program was only implemented to a limited degree.


Is there a way to tell whether a caddy contains the right movie without actually loading the disc in a player?

All CED's have a number printed on the raised center section of the disc that corresponds to either the number below the UPC (bar code) located on the rear of the caddy or to the stock number printed on the edge label of the caddy. The two numbers may not be exactly the same, but at least four consecutive digits will match up. Side 1 of all CED's also has the UPC encoded as a series of concentric striations on the raised center section of the disc. RCA had machinery in the manufacturing plant that would simultaneously read this engraved UPC and the printed UPC on the caddy at the time of disc insertion to verify the correct disc was being placed in the caddy with the correct orientation.


How do I remove a disc from the caddy to inspect the condition of the disc or to read the stock number stamped on the disc?

First hold the caddy upright on a table with the label edge resting on the table top. Use a key or other small instrument to push the latch on one side of the caddy opening towards the center of the caddy, and lift up about 1/4", then repeat this operation on the other side, and the spine will be free from the caddy (the spine is the plastic piece that encircles the disc and facilitates its transport to and from the player). When withdrawing the disc, it is important to never touch the grooved surface of the disc, since even a single fingerprint will result in a slight video degradation. Lift the spine up until the center hole of the disc is visible, then place the index and middle fingers through the center hole and press outward to get a grip on the disc. The disc can now be withdraw by bending the spine slightly and lifting the disc straight up. I prefer handling the disc this way, since it can be spun on the two fingers to change the disc orientation. Due to the friction of withdrawing the disc, it's common to get a mild shock when your fingers first come into contact with the disc material surrounding the center hole.


How can I tell whether a CED was originally a rental disc or has always been privately owned?

Most collectors want their discs to be from original private collections, since the disc may have been played just a few times, rather than potentially 100's of times for a rental disc. You can't assume that discs you're getting from private individuals were always privately owned, since rental stores periodically had sales on rental titles they wanted to dispose of, and they all had one final "everything goes" sale at the end of the CED era. Usually rental discs have (or had) a difficult to remove label identifying the rental store, so look for such a label or signs of its removal. Another technique rental stores used was to write the name of the store in permanent ink directly on the caddy surface to either side of the disc label. A more subtle way to distinguish rental discs is to look at the edge of the disc label where the title is printed. If this area is badly worn down, it's probably a rental disc. Most private collectors stored their discs like books in a shelf, while rental stores kept them standing upright in bins (the same way audio LP's were sold), and with customers flipping through them day after day, that edge label eventually got worn down. A few rental stores also coated their disc caddies with lacquer to protect the label surface, and if you find these discs today, the lacquer will have turned yellow, though the label underneath is still usually in good condition.


Why do some of my CED's skip, and what can I do to correct this?

Most of the skipping on CED's is caused by a condition RCA called "video virus," rather than by actual damage to the disc grooves. If the skipping goes away or becomes less pronounced when the same section is played repeatedly, then the skipping is attributable to video virus. This condition occurs when tiny dust particles on the disc surface have become "glued" to the surface by the right combination of high temperature and high humidity. Usually the stylus will break this dust free the first time it hits the dust, but sometimes the contaminated grooves will have to played a number of times to break the dust free.

Some discs will skip throughout play the first time they are played, but then not skip at all on subsequent plays. This is because the disc has not been played in a long time and required a conditioning play wherein the stylus "cuts" a groove in the glassy smooth lubricant on the disc surface.


Is there a way to safely clean the grooves on CED's?

The only recommended way to clean a CED is to play the disc, and let the stylus clean the groove. Removing the CED from the caddy and attempting to use something like an audio LP brush on it will only make matters worse. With extreme contamination, like a CED that has been immersed in muddy water, the disc can be removed from the caddy and washed under tap water, followed by a final rinse with distilled water and air drying. For cleaning with the stylus, there are certain VideoDisc player models that make cleaning the grooves easier. With the RCA SJT400 and SKT400, the PAGE button on the remote control puts the player in page mode, where it plays the same groove over and over. In this mode pressing the NEXT button will advance the stylus forward one groove with each push of the button. I use this technique to clear up skipping by putting the player in page mode right before the start of the skipping, and advancing the stylus through each contaminated groove in succession. The alternative is to use the VISUAL REVERSE button to repeatedly play that section until the skipping clears up.

Most Hitachi players (and their GEC McMichael and Sears counterparts) can also be put in page mode by a technique not known to many owners of these machines. Simultaneously pressing FORWARD NORMAL and REVERSE NORMAL on the player during playback will put it in page mode, and then repeatedly pressing these buttons individually will advance or reverse the stylus groove-by-groove. Page mode is exited by pressing the PLAY button.


Some of my CED's play fine at the beginning and end of a side, but poorly in between. What causes this?

CED's are designed so the edge and center section are raised higher than the grooves, so the grooves are not damaged when the player extracts the disc from the caddy. But putting a lot of weight on the caddy pushes it down so that the grooves are abraded by the inside wall of the caddy. This usually happens when a bunch of CED's are transported in a flat stack. The grooves at the beginning and end of play are protected, because they are closest to the raised rim or center section. It is very important when shipping CED's that they are stacked on edge instead of flat, with the box clearly labeled FRAGILE and THIS SIDE UP on the outside. I once received a box of CED's that the owner had stacked flat, and several of the discs on the bottom of the stack were badly damaged by the overlying weight rubbing the caddy against the grooves during transport.


How long can I expect my CED VideoDiscs to last?

This depends upon whether you're thinking of the number of times a disc can be played, or the life of the disc sitting on the shelf. RCA estimated the acceptable life of a disc at 500 plays. The discs don't fail suddenly, but gradually exhibit increased noise in the audio and video signals and more frequent skipping. When RCA was demonstrating the CED system prior to introduction, they would lock the stylus to a single groove for 20 minutes, and then play back over that section to show the disc was undamaged. But that doesn't mean the discs can be played 9,000 times (450 RPM x 20 min.), since the demonstration didn't take into account the wear and tear of loading the disc into the player 9,000 times.

The shelf life of a CED is basically unknown, but I'd make a guess that it's around a hundred years. Of course, that begs the question of whether there will be any functional CED stylus cartridges still in existence to play the discs. Some people might think a hundred year estimate is awfully long, but consider that vinyl audio records have been around since the late 1940's, so there are 50 year old vinyl discs out there that are still playable. The counter argument to this is that CED grooves are much smaller (38 CED grooves fit inside a single audio LP groove), so CED's won't last as long. But the CED stylus is correspondingly smaller and the stylus tracking force is much less (0.065 grams on CED's vs. 2 grams typically on audio LP's).

To ensure long disc life you should follow RCA's recommendations, i.e. store the discs vertically in a slightly cool environment of constant temperature. Subjecting the discs to wide temperature fluctuations, particularly on a daily basis, could significantly shorten that 100 year estimate.


Is it true that RCA VideoDiscs will be unplayable once the coating on the disc surface evaporates?

The coating applied to CED's was intended to reduce stylus wear, but its presence is not necessary for the disc to play. Actually, RCA found that this coating doubled the life of the stylus tip, and only to a lesser degree increased the life of the disc. And the coating is a silicone compound, so it is not evaporative, and probably has better long-term stability than the organic PVC of which the disc itself is made.


Why does the surface of a CED look like an eight spoked wheel when viewed under certain light conditions?

The eight spokes constitute the vertical blanking interval, where the television's electron beam moves from the bottom back to the top of the screen. The eight wider areas between the spokes constitute eight individual video fields (totaling four video frames). Thus the disc is divided into eight sectors numbered 0 through 7. The vertical blanking interval is used to store DAXI, or Digital Auxiliary Information, a 77 bit binary code that numbers each consecutive field on the disc, divides the disc surface in up to 62 separate bands, and also tells the player if the audio on the disc is stereo, independent channel, or CX encoded (for noise reduction). DAXI is used to update the LED minutes display (and on-screen display, when present), and also prevents the condition of "locked groove," since the system control microcomputer will advance the stylus two grooves is it fails to receive an increasing DAXI field number.


What is recorded on the unused sides of CED's?

With most program material less than one hour in length, and with most movies requiring two discs, there is an unused side with "nothing" recorded on it. But on inspecting these unused sides (usually stamped with the code 99999) there is still a band of grooves about 1/2" wide. Some collectors have speculated that there may be something viewable hidden away in these grooves, but on the few discs I checked, I found nothing except black video with the last 6 bits of the DAXI code translating to Band 63. This band number signals the system control microcomputer to initiate the end of disc sequence, causing the player to immediately raise the stylus off the disc. Still, it is possible that the Band 63 code is only recorded for the first few grooves, but on the discs I checked, this was not the case. On the J and K series players there is an easy way to spot check the complete width of the grooves by loading a disc and turning the power switch off as soon as "E" is shown on the LED display. With the player's cover removed the second reduction gear can be rotated slightly to the rear of the player, causing the pickup arm to advance over the grooves (a label on the inside of the cover illustrates the location of the second reduction gear). When the power switch is turned back on, the player will display whatever video signal it finds directly under the stylus, or the LED display will show "E" if the Band 63 code is still present (never rotate the second reduction gear with the power switch on, as this can break the gear or damage the stepper motor it is attached to).


Why do some CED caddies have two labels glued on?

Some CED's issued late in production have two caddy labels, one glued directly over the other. RCA prepared an equal number of discs and caddies, but if some discs were rejected during the visual inspection step of the production process, there would be some left over caddies. RCA started to "use up" these extra caddies during the final stretch of CED production, so the label underneath is for an earlier CED release. It is also possible that there may be some misprints on the label underneath. I have one disc obtained from an RCA engineer that has "Cat on a Hot Tin Roof" in front, and "Oklahoma" on back due to a misprint. Since "Cat on a Hot Tin Roof" discs had already been loaded into the caddies, these discs were given away free to RCA employees. But if they had caught the error while the caddies were still empty, the caddies may have been saved for eventual relabeling. It's my understanding that RCA also mis-stamped some discs, so the two sides are from different movies, but these discs were destroyed at the factory rather than being distributed among employees.


Were any CED's released with Dolby Surround Sound?

Some of the later CED's state on the caddy: "This VideoDisc has a matrixed surround soundtrack," but in fact, any stereo disc of a movie released in Dolby should still have the surround sound information encoded on the stereo channels. The CED Title Database indicates which discs should be playable in Dolby Pro Logic surround sound, according to Dolby Laboratories master list.


Do any CED's have dual soundtracks?

A small number of CED's were issued with dual soundtracks, allowing owners of stereo CED players to select the desired soundtrack with the Audio A-B button or switch. Several of the exercise and instructional CED's allowed the user to listen to just music, or music with instructions. "Space Shuttle: Mission Reports" had separate soundtracks for the astronauts' narration and NASA Ground Control. There also were a few bilingual titles which could be listened to in English or Spanish. Bilingual titles include: "The Adventures of Robin Hood" (CBS version), "A Boy Named Charlie Brown," "North to Alaska," "Return to Boggy Creek," "Snoopy Come Home" and "Those Magnificent Men in Their Flying Machines."


Are there any CED's with the image in letterbox format?

Several CED titles were issued in letterbox format ("Amarcord," "The Long Goodbye," "Manhattan," "Monty Python and the Holy Grail" and RCA's "King of Hearts"). RCA called this their "innovative widescreen mastering technique," and on the back of the caddy provided an explanation for the black bands at the top and bottom of the television screen. CED was the first video format to feature letterboxing, with the release of "Amarcord" in January 1984. This was eight months prior to the release of "Manhattan" on LaserDisc, which is often mistakenly considered the first letterboxed release.


Will any new RCA VideoDisc titles ever be pressed?

Though the pressing of audio LP's has been revived on a small scale, this seems highly unlikely with CED's, due to the smaller demand, the extensive facilities required to manufacture the discs, and the dissolution of corporate RCA in 1986. But legend has it that Thomson Consumer Electronics (owners of RCA's Consumer Electronics Division) still has in storage an electromechanical master recorder and disc pressing station. Perhaps someday they will release another disc commemorating the CED System. :)

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