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CED Digest Vol. 2 No. 3  •  1/18/1997


From: (Neil Wagner)
Subject: Re: CED Magic Update
Date: Mon, 13 Jan 1997 04:04:27 GMT

On Sat, 11 Jan 1997, Tom Howe wrote
to the CED mailing list:

> The CED Title Database has also been fully linked to
> the Internet Movie Database. The site URL is:

Hey, Tom, this sounds great.  I'm off to check it out.

Neil -

From: (Neil Wagner)
Subject: Videodisc History, Part 7
Date: Mon, 13 Jan 1997 04:04:31 GMT

Here's a big one.  A full two page article with photos and cutaway
diagrams from the July 1980 Popular Science.  (Sorry, I don't have
the capability to reproduce the pictures on the computer.)

      Optical vs. mechanical:
      the coming battle of the


Several incompatible disc machines will
tease the eager buyer next year.
by John Free

If you're confused by ads citing advantages of one video-*tape*
machine over an incompatible competitor, brace yourself.  More
befuddlement is brewing.  Early next year, makers of two--and perhaps
three--mutually incompatible video-*disc* players will each be
shouting the virtues of their products while cleverly knocking the
  Battle lines between two differing disc technologies took shape in
the early 1970's with demonstrations of early lab prototypes.  Despite
attempts at standardization, the lines hardened for two types of disc
players.  Optical, involving touchless disc playback with a laser
beam, and mechanical systems, requiring contact between the disc and
pickup stylus.
  Proponents of the mechanical system point out the basic simplicity
of their approach and its low costs for mass marketing.  Those favo-
ring optical systems stress the no-wear advantages of laser-beam
playback.  (Lasers last over 10,000 hours.)  Proponents of the optical
route also say that mass production of optics and a switch to solid-
state lasers will cut prices.
  Pictures I've seen from the newest Pioneer, Magnavox, and RCA
players are all amazingly detailed and noise-free.  What follows
should help delineate the differences between these players.

Optical machines: laser playback

Two optical video-disc players, made by Japan's Universal Pioneer
Corp. and by Magnavox here, are being test-marketed in a limited
number of cities.  Magnavox plans nationwide sales this year, Pioneer
next year.  The machines play compatible 12-inch discs by bouncing a
focused laser beam from a spiral track of microscopic pits etched on
the disc's reflective surface.  A clear plastic coating makes the disc
immune to dust and smudges from handling.  Two types of discs are
sold:  Those with a half hour per side of programming play at 1800
rpm.  Player controls enable you to freeze a TV picture, quickly scan
a disc, play forward and reverse slow motion, or pick a specific TV
frame by displaying its number on the screen.  Pioneer's VP-1000
player and remote control have a numbered key pad for direct frame-
number selection;  Magnavox's Magnavision requires scanning to the
desired frame.  Hour-per-side discs have more than one TV frame on
each circular track, so freeze-frame and related features will not
work.  (Playback rpm gradually changes from inner to outer tracks.)
Both players have output jacks for optional stereo hi-fi (or dual-
language tracks).  Pioneer Artists Inc. and other new software firms
will provide a stream of stereo/video music performances.  Also, movie
makers plan to release films to theaters and for discs almost simul-
taneously.  Discs cost from $6 to $25.  Both players, with minor
variations, have laser-based optics to play discs standardized by
Philips and MCA.  A beam from a laser is deflected by a prism and
mirrors through a lens onto the disc.  Metal between pits flashes
light back to a photodetector for conversion to an electronic TV
signal.  The entire mechanism moves radially on a slide linked to
the electronic servo circuits that control its movement.

[Caption of accompanying photo/diagram:  Feature-packed $749 Pioneer
machine has an optional $50 remote control.  Player accepts a plug-in
option for future digital audio discs.]

RCA: grooved capacitance disc

RCA's SelectaVision video-disc player has been completely overhauled
since it was introduced and field-tested several years ago.  The basic
playback principle is unchanged:  A stylus electrode, replaced every
two or three years, senses the TV signal as electrical capacitance
variations in disc grooves spinning at 450 rpm.  Playing time was
boosted to one hour per 12-inch disc side by doubling disc grooves to
just under 10,000 per inch.  Home tests showed that dust and other
groove contaminants from handling messed up pictures.  So, RCA's
improved SelectaVision has sealed disc "caddies."  Slip the caddy into
a player slot and the disc is loaded automatically.  This contact-
free, sealed-player approach sharply reduces groove contamination.
Spiral grooves, with four TV frames per revolution, do not permit
freeze-frame and similar features now.  These operating features may
go into future step-up models using electronic memories to store
images.  Two fast-search buttons, though, let you jump the stylus
forward or back to quickly locate a scene visually.  Also, two other
search buttons move the tone arm and display its position as time on
digital readouts.  RCA does not plan to include stereo hi-fi capabil-
ity on its initial model, slated for nationwide marketing early next
year.  The player's simple construction, plus many microcircuits,
should keep RCA's price under $500.  Discs will be $15 to $20, depen-
ding on content.  RCA's low-cost approach has gained powerful allies:
Zenith and undoubtedly other TV firms will market or make Selecta-
Visions.  CBS Inc. will help expand disc titles from 150 to 300 in the
first year.  Programs from several film companies range from classics,
musicals, current films, and how-to, to TV series such as "Star Trek"
(10 episodes) and "Victory at Sea" (a 90-minute version), and "Heidi"
and "Hans Brinker" for children.

[Caption of accompanying photo/diagram:  Metal-backed diamond stylus
forms electronic circuit to convert minute capacitance variations in
grooves into TV pictures.  Compact, microcomputer-controlled player
has viewing window.]

JVC: grooveless capacitance disc

Victor Company of Japan (or JVC here) rolled out a disc system in 1978
that combines the low-cost aspects of SelectaVision with the operating
options--freeze-frame, slow-motion, etc.--of optical machines.  Not
only that, JVC included options for a super-hi-fi audio disc.  It
calls the whole package its VHD/AHD system (video and audio high den-
sity).  Matsushita, Victor's parent firm in Japan, could offer VHD/AHD
through its Panasonic and Quasar subsidiaries.  An announcement about
marketing is expected this summer.  VHD/AHD hour-per-side discs are
just over 10 inches in diameter and rotate at 900 rpm.  Signals are
stored as capacitance variations, produced by minute pits in the con-
ductive plastic.  The stylus rests over several spiral tracks, distri-
buting pressure and minimzing wear.  (Stylus life is 2000 hours,
roughly 10 times RCA's.)  But the metal stylus electrode "reads" just
one information track and the tracking signals on either side of it.
These tracking signals keep the stylus on the right path by feeding
current to a coil/magnet combination on the arm, which can move side-
ways.  The cantilever arm can also be stretched or shortened instantly
to correct for speed variations (time-base errors).  Signals sent to
coils can be used to make the stylus replay one frame continuously,
move ahead or back at slow speed, etc.  JVC has also demonstrated an
optional random-access unit with a wireless remote control for the
main VHD/AHD player.  It has memories and numbered key pads for pre-
programmed display of selected TV frames.  Another plug-in option
unscrambles digitally coded audio discs that have a dynamic range over
90 dB and other super-fidelity specifications.  At this writing, JVC
has not revealed video software sources needed to sell its system
successfully.  Europe's Thorn-EMI Ltd., though, has agreed to produce
both players and software.

[Caption of accompanying photo/diagram:  Prototype player has slot for
loading discs from JVC's sealed caddies.  The stylus, which can be
electromechanically maneuvered, wears down along its entire length for
long life.]

Neil -

From: (Neil Wagner)
Subject: VP1000 weak audio output
Date: Mon, 13 Jan 1997 04:04:30 GMT

My brother just bought a Zenith VP1000 and about 20
discs at a flea market.  The player works okay, but the
sound output is very low.  He says he really has to
crank up the volume on his TV.  

The SGT100 I bought a while back is even worse, though
it has a bad picture to boot.  Still, I wonder if its
inherent in the CED format that the audio is weak, or
is it indicative of a problem with our players?

Alas, Tom, there was no manual with the VP1000.

Neil -

From: (Neil Wagner)
Subject: Re: checking the disc vs. caddy I.D.
Date: Mon, 13 Jan 1997 04:04:17 GMT

On Wed, 08 Jan 1997, David Potochick
wrote to the CED mailing list:

>Be sure to check the number on the disk and the number on the caddy
>and see that they match.

Fine, but how can that be done at a store quickly?  What's the best
and quickest technique for opening the caddy?

Neil -

Date: Mon, 13 Jan 1997 07:28:55 -0600
Subject: RE:CED Digest Vol. 2 No. 2

Hi Tom,
We were always told that a CED could only have 60 minutes of programming per
side, but Major Dundee clocks at over 61 minutes on side one.  Since the title
was relased towards the end of production, I have always wondered if this was
the result of improved technology, or whether CEDs always had the capacity for
more than 60 minutes of programming (and were there some 2 disk sets that
actually could have been issued on a single disk).  So I thought I'd throw the
question out:  "Anyone else know of any disks that had more than 60 minutes of
programming on one side?".
Bob Graham

Date: Mon, 13 Jan 1997 16:31:16 +0100
From: (Emmanuel Goedseels)
Subject: Music CED/LDs


I am collecting Music LDs.   If someone on this list has Music CED/LDs for
trade, please contact me !.

BTW, I would like to know how to find what it ever existed on LDs.  Is
there, somewhere, a catalog or a Web Site or something else which enable me
to find these deleted LDs.  I visited the catalog from this list owner, it
is really great ! I was just wondering if such catalog exists for LD's
(from '86 until now).
I know what is available now, but what was available just after the
"LaserVision/CED" times.

Thanks for your help.



Date: Sat, 18 Jan 1997 00:33:20 -0800
From: Tom Howe 
Subject: RE: Toshiba Turntable Drive Belt

For the past year, I've been trying to find original, unused rubber belts for
Toshiba, Hitachi, and Sanyo players to take precise measurements off. This would
be for the "CED Player Belt Replacement Guide" I'm working on. These don't
appear to be available anywhere, so I may have to finish the guide based on
approximations. But the good news is that most of the belts were off-the-shelf
designs, so it's just a matter of getting a substitute belt close enough to the
original to work.

Regarding the Toshiba Turntable Drive Belt (also used in the Wards and Elmo OEM
knockoffs), if the belt is merely falling off, it may simply be installed
insideout. The turntable motor pulley in the Toshiba player is unflanged, and at
first thought one might wonder how the belt ever stays on it at all. What keeps
it in place is the natural "curl" of the flat rubber belt where the belt has a
tendency when pinched to curl in one direction or the other. Toshiba put a white
mark on the outside of their belts, so the belt should be installed with this
facing out. If the belt is broken or stretched to the point that it no longer
fits, then a belt close in size to the original will work. The drive path in the
Toshiba player is 31" and design convention dictates a belt 5 to 10% smaller in
circumference. Therefore a flat rubber belt 28" to 30" in circumference with a
width of 0.3125" should work. The width is important, since narrower belts may
not have enough curl to keep them on the motor pulley. You may be able to find a
local supplier for this size belt by checking in the phone directory under
"Electronic Equipment- Service & Repair" .


Date: Sat, 18 Jan 1997 00:48:47 -0800
From: Tom Howe 

Subject:      RCA Videodisc player and videodiscs
From: )
Date:         1997/01/14

        Selectavision Videodisc Player SGT250 
        with 45 videodiscs titles (Casablanca,
        Rocky I thru Iv etc) These are CED discs
        (Capacitance Electronic) All for $250 
        plus shipping 

        mail to


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