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Posted by Bill Vermillion on 09/02/05 14:45
In article <devpns$q31$2@news.xmission.com>,
GMAN <glenzabr@xmission.com> wrote:
>In article <1125063830.252138.246920@g14g2000cwa.googlegroups.com>, "<>" <JSTRYKER483@YAHOO.COM> wrote:
>>Ironically, Steve, CED, which I do agree with you was "bad" in that it
>>skipped, had poor resolution, etc, actually is probably the most
>>durable home video format we've ever had.
>>
>>Magnetic tape gets stretched and is prone to drop-outs, laserdisc
>>"rotted" due to the manufacturing conditions and the glue, and DVDs are
>>very fragile and occassioanlly develop problems during the layer
>>change, and some old titles won't play at all (like some copies of the
>>original release of BOOGIE NIGHTS).
>>
>>CED was a vinyl disc like an LP record, and they still hold up today.
>>But, damn, are they heavy!!!
>They use a needle, how can that be good for any medium?
The 'needle' was not like the ones in phonograph records.
It basically was used as a mechanical servo, guiding the tangential
arm across the disk. The VHD system used an embedded servo and got
as much information on a 10" disk.
The data was beneath the groove stored as a capacitance signal, and
a groove could be played thousands of times with no loss of
capacitance, however the stylus would wear out.
The VHD 'sled' pickup used the same data storage, but with embedded
servo data it used a flat disk.
RCA did make a major mistake by relying too much on mechanical
means and belts, gear. By the time they got to the 400 series
they had direct drive turntable motors, getting rid of the belts,
and that made for a much more stable picture.
Bill
--
Bill Vermillion - bv @ wjv . com
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