CED VideoDisc and Player Discussion

[RT9342]

I was just wondering if anyone's ever seen or heard of any homebrew or bootleg CEDs. Or maybe discs made after 1986? I wonder how hard it would be too - if I ever formed or joined a band that actually made it, I'd like to put our music videos on EVERY format - U-matic, Beta, VHS, DVD, laserdisc, etc., and of course CED - just for the heck of it. Does Thomson or someone else still hold patents on the format? I would really just like to see how the picture quality of a CED would look if digitally mastered on modern equipment. I always assumed that the picture quality looks like it does because of the nature of the format, but I've noticed that all of my laserdiscs that were made during the CED era actually look worse than CEDs, while many of my later laserdiscs look about as good as DVDs. But without anyone making new CEDs, we may never know.....

[owenatverrs]

As far as my knowlodge reaches, no one ever made their own CED's. To make a CED, one would have to obtain alot of equitment and have an extremely clean workplace. As far as going to RCA and asking them to press discs, this would be (at the time) extremely costly. Most large bands (rolling stones, david bowie, Jackson, Pink Floyd) all had contracts through their record companies to have RCA made music videos for them. As far as quality, even with digtal remastering, I predict that their still wouldnt be much of an improvment with the video. Although I might be wrong. Unfortunately, we will most likely never know. CED today is an EXTREMELY unpopular format. What we in the collector biss call a "cult" format, kindof like "cult films". There are large groups of people who loved CEDs but they are only groups. I did a recent poll around my development, 70% of people hadent even heard of CED. The rest had heard of it/knew someone who had one. I can across NO ONE who actually owned one/parents owned one or even IN LAWS! This amazes me because the development that I live in was considered a very upscale one during CED's working years. As I see it the only way new dics's could be pressed is if somebody who had lots of money bought the old RCA equitment and marketed the hell out of it. But we can only dream.........

[SRSanford10]

RT9342 mentioned the possible patent situation. I believe these would have expired(17 years,is it?). "owenatverrs" comments seemed correct in that one would need some expensive, specialized equipment and a clean (possibly clean room ) environment. I have read the RCA Review papers from 1978 and 1981 about how this was done. It would appear that a laser cutting method (modulated by the FM carriers) would be the most likely way now. This was tried by RCA in the late seventies and extensively covered in one of the RCA Review articles. The system worked, but it had problems of poor yield of perfect masters compared to the favored electro-mechanical cutting of copper masters at half-speed.Lasers have improved, and it might work better now. I am trying to get my feet wet in this by laser cutting some compact disc format masters at home.
_________________
Scotty

[owenatverrs]

I never thought about laser cutting! I think with the right stuff if could be quite possible to get a great picture. The only other thing I would be cautious about would be friction noise. But thats what CX is for

[SRSanford10]

I looked again at my copy of "Optical Recording Techniques for the RCA VideoDisc" by A.H.Firester,I.Gorog,J.P.Russell,J.J.Gibson, C.B.Carroll, andW.R.Roach (all of RCA Laboratories) from "RCA Review" Vol.39, Sept.1978, pp.427 to471. The paper pointed out the difficulty of obtaining the 400 nanometer length of the smallest signal elements(which were necessary when the disc is at its minimum diameter). A helium/cadmium laser with an output of 15 miliwatts at a wavelength of 442 nanometers was used in order to cut into photoresist.I was thinking that perhaps a solid state laser with an output in the infrared range(800 nanometers or so) would be able to cut reasonably well in the outer section of a 12 inch disc. For reference, a 120 miliwatt continuous output 820 nanometer laser diode is available for $25. The cutting would probably have to be done into a metal film (such as bismuth), and then the cut film could be coated with photoresist and exposed to ultraviolet light.
_________________
Scotty

[Matlab]

Dr. Pab Datta, a member of our group and the inventor of the VideoDisc did several sucessful experiments on a recorderable unit late in the VideoDisc era. And then there was the rumor of an X-rated one made at the Indianoplis plant but never surfaced.

[SRSanford10]

Matlab mentioned in a recent post that a member of his group at RCA labs,Dr. Datta, had done some experiments on a recordable CED system. I was wondering if he(matlab) or others would be aware of the technology involved in this. Also, were patents ever issued or technical papers published?SRSanford10
_________________
Scotty

[Matlab]

Yes, I am aware of the technology involved. Basically the signal was played down on the stylus. I don't remember if he published but the details would be in my meeting notes that I maintained for the group.

At this time, he move on and developed the next generation method of CRT manufacturing. The last CRT plant was built using his dry technique for laying down phorphors.

[RT9342]

Interesting...still I'd like to someday try to make some sort of ghetto recorder to cut master discs and press copies. First, I'd work on doing LPs - I think if I had the equipment to press LPs, I could modify it to do CEDs as well. Talk about wishful thinking! I'll probably be dead before I ever get the whole thing going! By the way, I did find out the other day that the CED format IS in fact capable of producing some very nice video quality. See, my main suspicion to most of the picture problems that I've seen is in the film transfer. Now, sometimes when I buy CEDs, I buy them in lots, and they may have discs I don't really care to have, like kids' videos. However, after accidentally shredding one of my movies when I was testing it in a player that "fell apart", I decided to now usse those unwanted discs for testing. The other day I popped in a kids' video for testing a machine, which was apparently "filmed" on tape, not film, and directly transferred from that tape to CED. And the picture quality was incredible on that disc! I mean it looked better than VHS and even comparable to laserdisc! Actually even better than laserdisc in the sense that the bright colors (especially blue and yellow) had hardly any of those off-tint smears that laserdiscs tend to have. I did notice that fine vertical lines in the video were not crystal clear, but it looked pretty darn good!

[SRSanford10]

Matlab, Thank you for the information on the recordable CED system. Any further information that you can provide without violating confidentiality agreements would be of interest. RT9342-Check on Google under categories such as audio experimenter or audio amateur. There are some sites that have info on "ghetto"cutting of LP's. CED's are much harder because of the very small signal elements needed in the direction the stylus is moving and also because of the mechanical problems of eccentricity and disc flatness during the record time. I'm thinking for experiments that it might be possible to get small enough signal elements in the outer diameter of the disk with an inexpensive laser cutter. I'm planning on having a luminance carrier only(black and white information) with the CED FM frequency swing of 4.3MHz sync tip to 6.3MHz peak white. The mechanical problems are still difficult. Lots of experimentation will be needed to solve them.
_________________
Scotty

[RT9342]

Sounds like fun...I just hope I can pull it off in my lifetime, and before I'm the only CED collector still alive! I'd look like a fool trying to revive an old format that no one knows about (I probably already am a fool just thinking about doing it now!). I just wonder if it's worth the effort, or a waste of effort (like trying to produce 78s or 8-tracks...or even the old cylindrical records that were around before they developed the "new" disk records - I bet most people don't even know about the old cylindrical records!).

[Matlab]

I just spoke with a fellow ex-researcher at RCA/GE/SRI International and got the details about the recordable disc. A patent was filed so it is public knowledge if you know where to look. It did involve a laser. Pab's old technician, Ron Friel may actually be available consulting.

PS I have a large collection of disc (930±), lots of players, spare parts, and research type goodys I need to clear out to expand the lab.

[SRSanford10]

Thanks to Matlab for further information on the recordable CED system. I would be interested in e-mailing Ron Friel about possible consulting on this project. Also, Matlab could send me a short list of the research type goodys he mentioned. I am doing this as a personal project and don't believe it will have any commercial value. Other members of the forum have pointed out that even if the difficult technical problems could be solved there would be a problem getting rights to copyrighted material due to the small universe of people with CED players. I can be reached at:RSSanford@direcTV.com.
_________________
Scotty

[cedmagic]

You can get a list of patents issued to Dr. Datta, with further links to their full contents, by clicking the patents link on his Who's Who page:

http://www.cedmagic.com/mem/whos-who/datta-pabitra.html

I didn't see anything that appeared to relate to recordable VideoDiscs from the list of titles, so it's possible a patent was filed but not issued.

--Tom Howe

[Matlab]

A friend call me from the lab and told me that Ron retired to Florida. I will reach out to him and see if he is interested. Roughly, the disc without silicone oil was coated with chrome. A laser then made the appropriate holes exposing the carbon black/PVC layer underneath. The disc was then oiled.

It has been long enough that the patents on the VideoDisc should have expired, e.g. 20 years from filing.

[Matlab]

I spoke with Ron Friel in FL this morning. He is happily retired and really doesn' remember the details. However, he did say that a number of people were involved. Post a request on this listserve may work.

[SRSanford10]

Thank you to Tom Howe for looking up the patent information.Perhaps he is correct that a patent was not issued. Matlab, thank you for the effort to communicate with people involved. I will post a request for some help in the near future. The information you gave us leads to some ideas on how this might work.
_________________
Scotty

[matt carr]

So has there been any breakthroughs in this area, or has everyone just more or less given up.

[RT9342]

Whoa - I forgot I even started this thread! It's sure been a while. I guess most of us kind of forgot about it. I used to be the experimental kind of person, and at one time I would be one who would try to find a way to make a homemade CED, but I guess I kind of got burned out on that kind of stuff. All I really do with CED anymore is just watch old, cheap movies.

[SRSanford10]

I had thought about this and have done a lot of library research on the idea. My current job and living needs preclude doing hardware experimentation . Hopefully this will change when I'm retired in a few years. Please check : lathetrolls.phpbbweb for great info on disc recording in general. Also, RCA Review and RCA Engineer years of 1978 through about 1983 for many engineering papers on CED(available at large university libraries).
_________________
Scotty

[Rixrex]

I doubt if any individual would have enough resources to do something like this right. And then while it may be satisfying to technically-minded persons, what's the point (other than this satisfaction, I mean)?

Collecting CEDs and keeping the players up is already a good effort for anyone, and personally, if I had additional free time & money, I'd put all my players sinto operation, round out my CED collection and begin an HD DVD collection (there's even fewer titles than CED!)

[matt carr]

[Rixrex]

Exactly, there is no other point to doing this, and no tangible benefit, so it's basically just a 'Spruce Goose' adventure.

If one has the funds to use toward such an endeavor, go ahead. I can think of a myriad of better uses, both personal and societal, for such resources.

[matt carr]

[Rixrex]

Can't think of anything better to do with money than attempt a pointless technical exercise? One that contributes nothing more to scientific knowledge nor resolves any social ills, a veritable Don Quixote journey.

[matt carr]

[SRSanford10]

Rixrex posted about the attempt to record in the CED format as a pointless technical exercise. I believe that one can learn a great deal by experimenting in a difficult field . I see examples on the "Lathe Trolls" site of much home experimentation in audio recording and in one case, limited resolution video recording. Experimentation of this type can lead to future advances. This is why there are prizes for long distance experimental aircraft. I would agree,however that keeping CED players and discs going has its own rewards and challenges.
_________________
Scotty

[matt carr]

[7jlong]

Does anyone remember those laser-etched LPs from Split Enz and Styx? The ones that had CED-looking rainbow patterns burned into otherwise perfectly playable albums? They're easy to find in a google image search if you aren't familiar.

I don't know much about the technology that would be required to get from point A to point B, but this gimmick is at least 20 years old. Laser etching has presumably advanced by leaps and bounds. I could be wrong, but it seems to me that the main detail that would make such a project prohibitively expensive and/or unattainable would be making the stampers and then pressing discs. If you run with a CD-R kind of idea, it might make more sense to bypass that end of things altogether and laser-etch playable discs directly.

Otherwise, what I would really love to see is the folks who make the laser turntable come up with a model for CED playback. Even just once for the hell of it. The major problem there is that dust is such a hindrance for the laser turntables that the purchase price includes a VPI record cleaner. Not sure how they'd deal with dust problems with CED (though we are admittedly more forgiving of playback errors out of habit).

Sadly I don't see it happening, though. Compared to the audiophile vinyl crowd, CED collectors are but a tiny blip of a market.

[Rixrex]

I'm not a technically moribund individual, nor do I think that scientific and technological experimentation does not have good value. Quite the opposite, I believe it does have great value to society.

However there is a very significant difference in scientific experimentation of new forms of technology, little explored or unexplored areas of science, or beneficial advances of current technology, that sort of thing, and retreading old ground. The former is where great discoveries and advances are made. The examples others quoted above as proof are actually within that realm.

Recreating already existing technology is not advancement. The argument that one might stumble upon some sort of unknown valuable application is spurious and of dubious value to what is already known in science and, specifically, video technology. If one thinks otherwise, then one is akin to Don Quixote. My point was simply that time and money spent toward a home-made recreation of what we already know could be better spent in other ways, including truly advancing scientific experimentation.

My father was one of those many individuals who worked at RCA in Indiana while the CED format was designed, developed, created and marketed, and I have strong memories of his descriptions of the format during this time, that is of what he could actually speak about, and then seeing it upon completion. It was truly a marvel at that moment in time, the pinnacle of grooved disc recording technology, but both he and I personally felt that the laser format would eventually surpass this. I have serious doubts about any home inventor being able to actually do more than what RCA already did, as that was probably more extensive than most of us realize.

As we live in a free society in our nation, you may spend you money and time however you wish, towards any sort of ideation regardless of consequence.