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CED Digest Vol. 4 No. 34  •  8/28/1999


Date: Mon, 23 Aug 1999 00:28:00 +0000
From: Stan
Subject: Cleaning CED

I'm a retired RCA engineer that moonlighted for a guy who rented CEDs. 
Although I was not directly connected with RCA's CED operation, I saw 
a mention in a company tech pub of two CED players that engineers in 
NJ had constructed for testing that read regular CEDs optically with a 
laser diode.So even if we run out of stylii, there's hope for a 
creative tinkerer. When RCA approached the end of their production of 
CED machines, they offered factory returns to their employes at a very 
reduced price and many of us bought them.

I repaired players for a guy who rented the discs. WE experimented 
with several techniques for cleaning skippy discs. The problem is 
replacing the lubricant that the disc makers put on them. I had fair 
luck with Windex. Lay the disc on a clean, lint free towel and clean 
in a cicular motion with a soft cloth following the grooves. More 
recently, I tried Armorall. It must be applied very lightly. I used 
one of the sponges they sell saturated in a foil packet. They are much 
to wet in the beginning, and the excess will have to be wiped off (not 
easy to wipe armorall off of anything), but work better as the 
Armorall gets used up. The discs will be noisy when first played after 
either cleaning, especially the armorall, but improve when played 
several times. I would say they never get back to original quality, 
but the skipping is greatly improved. Try it with a expendable disc 
and make your own judgement.

We had best luck cleaning sylii with the edge of our T-shirt VERY 

I have a dozen or so brand new sylii which do not work. Carefull 
examination with a microscope reveals no problem, but they do not 
play. Any ideas? I suspect the gold foil does not reach the end of the 

Most common electronic problem with RCA and Toshiba players was the 
video demod IC. They are the same in both machines although numbered 
differently. I believe the 24 volt power supply was very poorly 
designed in the RCA machines and subject to going overvoltage. We 
sometimes added a 3 lead 24 volt regulator chip to solve the problem. 
The 324 op amp that they used in the 5 volt regulator was also a high 
failure item for the same reason.

I wish I could remember all the things I learned working on the 
machines and pass them on to you, but it has been a long time.


Subject: Re: CED Digest Vol. 4 No. 33
To: (Tom Howe)
Date: Thu, 26 Aug 1999 14:32:32 -0400 (EDT)
From: bill

> So with its high capacity why hasn't this new CED system been
> marketed? Well, the system would still require considerable
> development work to reach the point of being manufacturable,
> and it would have to compete with CD-R, DVD-RAM, and the cheap
> magnetic disc technology we have today, all of which have the
> ability to record with consumer versions. Since the CED Cutter
> requires an absolutely vibration free environment to accurately
> cut the groove, it's unlikely a consumer mastering setup would
> be available. And the 5-inch optical disc has the potential of
> still being backwards compatible to CD Audio and CD-ROM as its
> capacity continues to increase with the shorter wavelength blue
> and ultraviolet laser diodes that are being researched.

Contact storare is alive and well.  IBM is working with it, as stylus
devices can be made smaller than readiang by laser - of course
we're not talking about the stylus in the CED.

(for some interesting information on just how low a level you can
go - hit IBM's web site in the Switzerland research center, and 
see the abacus that uses single molecules for beads, and how they
physically push them around).

One company doing research and development in high density system -
though not contact - is getting 200GigaBytes in CD sized

To really be surprised look at their Rosetta product.  It can store
between 1000 and 100,000 images on a 2" disk.  The disk is
"eye-readable"  Pixels are 100 namoeter wide.  (That's 100
billionths of an inch).

Los Alamos Naitional Labs did testing on them.  (It is not said
whether Nosram funded this or not).

The disk would 'last a long time' in salt-water.  

They also do not degrade at 100C/210F and up to 300C/570F
Time of exposure at those levels was 65 HOURS.

Degradation set in at the next test level 450C/840F, and 550C/1020F

Today's techology is nothing short of amazing.

A year or two ago Nosram was working in data storage areas
with a 2" disk - that was truly archivable - in differernt levels
of protection.

The very high density 2" stainless steel disks would easily 
survive the (approximate) 1500F in an office fire.


Date: Sat, 28 Aug 1999 07:32:54 -0700
From: Tom Howe <>
Subject: CED Patents Table

The table listing about 700 patents relevant to the CED system is now
available at CED Magic in the CED Museum section. The patents have
clickable links to their full text and images at the IBM Intellectual
Property Network and US Patent & Trademark Office. The page also has
some suggestions for locating patents on VideoDisc systems contemporary
to CED like Teldec, VHD, and Thomson-CFS. I'm working on the Featured
Patents pages now.



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