Conference cookie::notes$archive:cd_v1

    
                                   
    This technology was developed here in Santa Clara,Ca.
    

    For Legal copying at home, I'd prefer DAT over CD.  There have been
    a lot of notes on how CDs skip in a car.  I'd guess that a tape
    would never skip from vibration.  My wife dumps her cassets on the
    dash.  Sometimes the cases take on strange shapes after a hot day.
    I bet a DAT will take a lot more of a beating than a CD.  A tape
    should cost less than a CD, so if a DAT gets sat on, it will be
    cheaper to just re-record it from the at home CD.
    
    Jeff

    I would say that a CD is more resistant to damage than the tape.
    The plastic CDs are made from is highly resistant to warping at
    temperature extremes, and I would bet that extreme cold would bother
    a tape much more than a disc.
    
    As for tapes costing less than a CD - maybe in about 10 years, but
    I dunno.  CD manufacturing technology keeps improving over the years.
    
    				Steve

    
    Although  I've yet to see a DAT, I imagine it must have moving parts,
    almost by default making it more likely to be damaged.  Doesn't
    the tape also touch the heads, just like a cassette?  This would
    wear it out faster.
    
    Bruce

    The DAT's will also be magnetically vulnerable. After a nuclear
    war, you'd still be able to play your CD's until your hair
    falls out (assuming that you had the foresight to buy one of
    the tube CD players, that is -- I knew there had to be a good
    reason for having one), but your DAT's will just be so much
    junk once the electromagnetic pulse of the exploding warheads
    erases them.
    
    --- jerry

    I just happen to be over in the U.K. on business at the moment.
    In the music shops over here, CDs are 11.99 Pounds (~$24 at the
    current exchange rate), and prerecorded DAT tapes are 31.99 Pounds
    (~=$64).  I'm sure some of this is because it's new, but I expect
    that it will be long time before the two media are competing with
    each other price-wise.
    
    B
    

    
    This Tandy CD technology was mentioned in the AUDIO conference and
    it turns out that it's the WORM technology.  Write Once, Read Many.
    So it isn't like DAT at all.  Apples and oranges.
    
    Jim
    

    I forsee this WORM CD being used in record shops, where you
    can buy music by the track and you can mix and match the artists
    and behind the counter they will put what you bought onto one
    CD.
    
    Wouldn't it be nice to be able to have only the tracks you like
    on a disc w/out having to program your player to skip tracks you
    never want to listen to.  And be able to have every CD filled
    to the max time possible.

     Hmmm..........that does sound interesting. I read somewhere that
    someone is already using this concept (on audio cassettes). I believe
    it was in Japan though, a country noted for rather lax copyright
    laws. Here in the U.S., any business that would custom create a
    CD from various artists and companies better have a battery of lawyers.
    
    
                                 Ken
    

Re: .9

Actually, there's  no  need  to  go through shiny plastic pitted disks... as
memory  gets  cheap, I forsee music being shipped on silicon. Then your home
computer can not only select which tracks to play and in which order, it can
modify them (shift the entire spectrum by adding a constant)...

    Somneone already has devices in record stores that lets you build
    your own cassette.  I don't know what the legal issues are.  I have
    only read of this device (sort of like a juke-box), have never
    seen one.
    
    				Steve

    "... raised tensions in the recording industry ..." - not again
    
************************************

TANDY'S CD SYSTEM

	"The Broad Potential for Tandy's CD System" (NYT 4/27/88, PP:D7)

If Tandy can bring its CD-THOR system to market, it will be a technological 
coup over the Japanese, and will position Tandy as a much more prominent 
player in the computer market.  Some observers say that the erasable and 
reusable CD is possible from Tandy, others wonder if Tandy could have 
surmounted all of the technological barriers.  

Tandy is not the first company to announce an erasable optical storage
system, but it is the first to concentrate on the consumer, rather than the 
professional computer data storage market.  Because CD-THOR can be used for 
storing anything digital, it could lead to further integration of PCs, data 
processing, music, and video images.  The technology has also raised 
tensions in the recording industry, because it would allow for the precise 
copying of audio CDs.  

Tandy's CD-THOR relies upon a dye-polymer, embedded in the CD.  A laser 
writes information in the dye-polymer, creating pits.  By tuning the laser 
to a different frequency and power, the pits can be smoothed out and the
information erased.  Tandy plans to market CD-THOR by 1990, priced at about 
$500.

    RE .3: People who think CDs skip a lot in a car seem to either have no
    expierence in CDs in a car CD player or have a portable that they have
    kludged into their car audio system.  CDs are not effected by heat (I
    left a CD that I didn't like for a sunny summer week inside a car in
    direct sunlight and there was NO damage).  I dump my CDs on the dash;
    leaving them in the car all of time; and generally I am only careful
    with borrowed CDs; and I have had no problems at all (including
    skipping given a healthy CD player) in the two plus years I have had a
    CD player in my car.  No CD has ever suffered at all.
    
    DATs have moving parts and as such as subject to the same kind of
    problems that cassette tapes have.  With the rotating head technology
    used in DAT, I would expect that the tape really will take a beating
    (like it does with VCRs) and if that DAT tape starts to bind or get
    dropouts its advantages over car cassettes diminish.  Blank DATs are
    expected to cost $10-$12 each in the US (about the cost of a CD).  So,
    if you DAT gets sat on you are out another $10-$12 for another DAT. Not
    only that, it takes time to copy a CD to anything (DAT or cassette).
    It doubles the cost of your music to copy to DAT.  I suspect that at
    least initially, DAT players for cars are going to be very expensive
    and prone to various failures until the manufacturers go through a
    couple of generations of car DAT players.  I am going to wait at least
    4 or 5 years for a DAT purchase, and I will only make DAT plunge if
    music is available on DAT that isn't going to be available on CD. 
    

    re: .12
    
         They have one of those make your own custom tape machines in
    The Wherehouse in Mountain View, CA.  At the price they charge per
    song there's no doubt that you're paying the proper amount for a
    copy of the song.  I forget the correct prices, but $1.50 per song
    seems to ring a bell in my mind.
    
    ASP

     to the person a couple back who leaves his CD out in the car-
    
    do you lock your car?
    what kind of music do you like?
    where do you park?
    
    8^)

    re .8	Nope, it ain't WORM !

    Best lay technical description I've seen so far in the "popular"
    conferences was in the MacIntosh notes.

    	R
    

    EMP does not erase tapes.... any more than living near a big TV
    transmitter does.
    	
    What EMP is: a large untuned, undirected electromagnetic wave, spectrum
    from about 100 KHz to about 100 MHz.  total power: BIG.
    Volts-per-meter: up to 10,000. 
    
    What causes it: Compton scattering of electrons by the X,gamma-rays
    emitted by the fusing core. The electrons move a lot further (and
    a lot faster) than the nuclei.  Net result is a big electrical current
    impulse.  The atoms recombine quickly; but the current induces a
    magnetic field... so you get R.F transmission.  The wavelengths
    are of the same order as how far the electron gets- it doesn't go
    shorter in wavelength than the plasma fireball (about 1-10 meters),
    nor longer than the compton scattered distance (about 1 kilometer).
    
    It doesn't erase tapes.  It just induces RF voltages and currents.
    A tape could concieveably be erased if it was next to a long conductor-
    but tape takes a LOT of magnetism to erase.  More magnetism than
    a single-turn electromagnet (like a pipe) can generate, before the
    pipe melts from resistance heating...
    	
    Hence, I doubt if tapes themselves would be erased.
    
    Now, transistor electronics are sensitive to voltage overloads;
    unshielded, unprotected CMOS is probably easiest to fry.  The frying
    is due to induced voltages, not induced currents.  Light bulbs (even
    fluorescents) didn't fry in Hawaii when they shot Starfish; just
    a few burglar alarms (based on monitoring the current through a
    long loop of wire running across every window in a warehouse) would
    go off.
                                    
    -----------
    
    Blow out my DAC's.  Believeable.  Blow out my tweeters?  Not likely.
    Erase my tapes?  N.F.W. - the house wiring would be plasma before
    enough field would be generated.
                                   

    re: .6
    
    I haven't slept at ALL in nine nights!  At least if you are going to say
    something, get it right!
    
    re: .19
    
    Thank you.  I'm so relieved.  Good night.
    
    								-mr. bill