Hitachi VIP201P

FORMAT: CED

DATE: 1983

PRICE: £300
[1994: £480]

xxcm

 
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The CED format was developed in the US by RCA, under the name SelectaVision - the same name as their long-obsolete holographic tape system (see the First Videocassette Revolution), and also the name they used for their first VHS decks! The SelectaVision Disc format was launched in the US in March 1981, and marketed in the UK in 1983 under the name CED (Capacitance Electronic Disc) by Hitachi and GEC McMichael.

CED uses vinyl discs, like normal LP records, which are read using a sapphire stylus. The signal is stored as variations in the electrical capacitance, which can be read by making the disc and the stylus part of an electronic circuit; the variations in capacitance on the disc affect the behaviour of this circuit, allowing the stored signal to be picked up.

The grooves on the disc are some 38 times finer than those on a normal LP record. They can be packed so tightly because they are only needed to guide the stylus, unlike a record where the audio signal is stored as wiggles in the groove itself.

The disc is lubricated, and to protect the sticky surface from dust and damage, they are stored in protective sleeves or caddies. The whole thing is inserted into the machine, and then the caddy withdrawn leaving the disc behind ready to play. To remove it, the caddy is re-inserted, and when pulled out has the disc back inside it. So the user never sees the actual disc!

Right: a CED disk half out of its caddy.

Using the machine is simple, but perhaps not entirely intuitive. There is no power switch - it turns itself on when a disc is inserted, and automatically begins to play when the caddy is withdrawn. To stop playing, the Reset button is pressed to return the stylus to its "home" position; the caddy cannot be inserted until the machine has completed this process. Annoyingly, the machine turns itself off immediately a disc is withdrawn, which is irritating when you are simply turning a disc over since the TV screen reverts to hissing snow.

As well as normal play, the VIP201P provides fast and super-fast play in both directions - the super-fast mode skips tracks, giving a jumping effect, while the fast mode is smooth. There is no freeze-frame, the pause control simply giving a black screen - the stylus having been lifted from the groove - and no fast search other than the two picture search modes. So one of the key features of video disc, instant access to any part of the recording, is not available.

Lights on the front tell you which side is playing, where in the disc you are (a light moving along a scale marked in minutes) and whether the disc is stereo/bilingual or mono. Bilingual discs provide two independent soundtracks: two different languages, or perhaps commentary and music, with a button allowing you to switch between them.

CED discs play for up to an hour a side (although the time display is marked up to 75 minutes, for some reason); they can of course play for less than an hour, and the machine will reset itself automatically at the end of the recording. The picture quality is very good, somewhat crisper than standard VHS and with very pure blacks. The discs themselves are large and heavy, the caddy measuring about 32 x 35 cm, and are much thicker than an LP or LaserDisc.

Since the stylus is in physical contact with the disc, playback - and particularly searching, which forced the needle to jump the groove - will always cause a certain amount of wear and tear. Worn or scratched discs can jump, like records, but curiously the jumps caused by all but the most severe wear are not that obtrusive.

Internally, the machine is satisfyingly simple; it is effectively just an automatic record player. The disc is lowered onto a turntable (automatically on this model, though earlier versions used a manual raise/lower lever), and a motorised stylus unit (visible at the top of the picture) moves across and engages with the groove. The disc is played from outside toward the centre, like a normal record, at 500 rpm - 3 frames per rotation.
A close-up of the CED disc surface, showing the boundary between two frames.

Like records, the discs are not always pressed perfectly centrally, in which case the stylus can be seen to wobble from side to side as it plays. This seems to have no effect on either the picture or the sound, so the machine must compensate in some way; even minor variations in the timing of the video signal could cause the picture to judder, roll or even break up completely.

The stylus unit can be removed for cleaning or replacement, via a cover on the left. The fact that this is easy to open, and not hidden away from the casual user, suggests that such actions were needed relatively frequently...

Right: the stylus compartment opened, with the stylus itself laying on top of the machine. The stylus is just dropped in, and the lid closed, and you're ready to go again.

Despite being launched on both sides of the Atlantic, with a substantial catalogue of discs (around 250 were available), the format was suddenly scrapped in April 1984, both in the US and Europe - only a year after reaching the UK, and just a month after RCA had publicly given assurances of their continuing support for the system.

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