CED VideoDisc and Player Discussion

[ketonic_dude]

So I was looking to make a thread here about how to read the information written on the disc itself as well as decode the UPC and etc. In the process of gathering information I sent an email to John Stevens over at CEDatum and he sent back pretty much everything I was going to include here as well as links to some stuff Tom Howe came up with on the actual CED Magic page. So it made this pretty easy. Here is what John said.

"Hello Josh,

Replying to your message of July 13. I contacted an RCA friend who worked
in QC at the RCA Rockville Rd, Indy videodisc plant and we compared notes.

The following should help:


The relationships between the recorded copper substrate, Master, Mold (or
Mother), and Stamper are shown here:
http://www.cedmagic.com/disc-manufacturing/00-disc-manufacturing.html

1. Aluminum Blank- the plate which is coated with copper.
2. Copper Substrate- the copper-coated plate into which the grooves are cut.
3. Recorded Substrate- the copper-coated plate after the grooves are cut.
4. Master- a negative replica of the final disc surface electroformed from
nickel to a thickness of 0.015-inch.
5. Mold- or Mother, a positive replica of the final disc surface
electroformed from nickel to a thickness of 0.015-inch. A number of molds
are made in the VideoDisc manufacturing process.
6. Stamper- a negative replica of the final disc surface electroformed from
nickel to a thickness of 0.0075-inch. A number of stampers are made from
each mold, and the stampers are used to compression mold the final disc.

More information about the UPC is shown here:
http://www.cedmagic.com/home/upc.html

RCA CED Format:
60 = 60 cycle (US NTSC)
50 = 50 cycle (European)
B = Bilingual or dual audio channels
M = Monaural (1 channel) audio
S = Stereo audio
C = Closed-captioned
61 = 60 cycle + “banded”
62 = 60 cycle + “interactive”

For example, Looking for Mr. Goodbar is 60 cycle, monaural ……and would
usually be marked as 76476-00617 and 60-M . On the pressed disc, the
scratched markings usually indicate the number of molds and stampers that
might be made from a master or recorded substrate. Stamper life varied,
but usually at least 500 to 1000 discs could be produced from a single
stamper.

We have no information on the final quantity of pressings made per videodisc title.

John"

So there you have it. Go ahead and print all this out for your personal records and then you can refer to it anytime you need to read a disc. Hope that helps.

[happycube]

Semi-related: what were the production yields?

[SelectaVision420]

so does that stand to reason, if a disc is not known to have a higher number, that an approximate amount of pressings can be approximated by knowing the highest mold number? example, all of us find a "rare" disc and report our stamp number, and the person with the highest stamp number say "3" that would mean that no more than 3000 pressings were made... does that make sense?
_________________
(2)Sears 274 & 934(80150,10&11350), sft100, sgt250, sjt 090-400, vp550, VDR3000, VP2000 & 4000
complete '84 Dimensia Owner

[ketonic_dude]

That could still be way off actual numbers though Tony. What if one stamper didn't get pressed right, then it would have zero discs but still get counted. Plus John said 500 to 1000, if there was 3 stampers then there could have been 1500 discs or 3,000 discs. Or if two of those stampers had issues and didn't press any discs or only pressed a handful for some reason there could be as little as 500 or 600 even if it's listed as 3 stampers. But one could reasonably presume what you are saying is correct even if it may not be 100 percent accurate.

[ketonic_dude]

We can certainly try it. Some of the discs I have seen the fewest of include, Hollywood Hottubs, RSVP, Richard Pryor Live and Smokin, Rascals, Truck Stop Women, The Jester, and I can probably think of a few more. Anyone else have any of those? I've only ever seen 2 maybe 3 copies of each.