From: damiel@netcom.com (Paul Theodoropoulos)
Subject: Re: Reasons for Amiga CD-ROM
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Organization: Netcom - Online Communication Services  (408 241-9760 guest) 
Date: Thu, 31 Dec 1992 10:18:12 GMT

In <C043q8.8pC@news.iastate.edu> barrett@iastate.edu (Marc N. Barrett) writes:
>  I doubt it.  Cassettes recently got a reguvenation, from new DAT drives that
                                           ^j
>can store digitally on ordinary cassettes, and play old analog-written 
>cassettes.  This is highly attractive to people who have lots of old cassettes
>and want to still be able to use them.

the new DCC (digital compact cassette) *is* digital audio tape, but it is 
misleading to refer to it as DAT, which is in fact R-DAT. DCC is closer to 
the original S-DAT specification, but even here the comparison fails, because 
while S-DAT specified CD style data and sampling rates, DCC employs data 
*reduction* algorithms on the incoming signal.

further, DCC recorders record on DCC media, not on ordinary cassettes as
stated above.

platter media enjoy the inherent advantage of virtually instantaneous random
access of the information encoded on them. this is why DAT has never been
a barn-burner, and why DCC will suffer the same fate.

i see nothing to preclude a person who still owns conventional audio cassettes
from keeping and playing those cassettes if they choose to invest in mini-disc
technology.

the sad part of it is that both DCC and mini-disc use the aforementioned
data reduction, and do not have audio specs as good as CD. and since CD
is certainly not the ultimate in reproduction technology, we are taking a 
step *back* in quality. not a good trend - but that's another story.

>   Read-write CDs have been promised for some time.  They are here already,
>but only in very-expensive units that can only erase and re-write a CD a
>very limited number of times, and only to special CDs.

magneto-optical recordable media can be rewritten an unlimited number of
times. this is the technology used in the mini-disc. prices are falling
steadily on the CD format drives. and *of course* its to a special CD - it 
has to be a rewritable medium. or were you planning on writing over your
existing CD-ROMS?


>   Even after read-write CDs do finally arrive, the manufacturing costs of 
>such CDs will likely be higher than for CD-ROMs.  So I expect CD-ROMs to stick
>around for a long while even after read-write CDs are available, especially if
>all read-write CD drives are rigged so that they cannot be used to copy
>CD-ROMs.  The audio industry will almost certainly insist on circuitry to 
>prevent read-write CD drives from copying audio CDs, and the software 
>publishing industry may get on the bandwagon by insisting on similar circuitry
>for CD-ROMs. If so, CD-ROMs would continue to be very attractive distribution
>medium for software publishers.

uh, this makes little sense. first, the manufacturing cost of rewritable 
CDs is no more a factor than for rewritable magnetic media - yes, its 
obviously more expensive to make a rewritable disc, but not significantly
more so than CD-ROM discs - and relative to harddisk media, it is an order of 
magnitude less expensive. rewritable disks will be purchased by end-users, not
by distributors (by and large). CD-ROMS will still be employed for prerecorded
data distribution.

but - "if...CD drives are rigged so that they cannot be used to copy CD-ROMS."
??? its digital data, marc. if someone doesn't want their CD-ROM disk copied,
they can use copy protection on the disk, just like they do now. are harddisk
drives rigged so that you can't copy proprietary software onto them? no. same
difference with rewritable CD drives. the "rigging" is in the software code,
not the drive/media.

CD audio is stored in a different data format than CD-ROM data.
In fact, a recorder has to be specifically *designed* to record CD
audio data, since CD audio data is realtime, streaming information, 
unlike CD-ROM data. and anyway, the Q subcode channel indicates whether a
disk is copyable, and also indicates whether a disk is CD audio or CD-ROM.

the number of plain factual errors in your post borders on the ridiculous,
marc. please, rather than just manufacturing "information", you might try 
reading about that which you pontificate.
-- 
paul theodoropoulos     damiel@netcom.com     (hooools@well.sf.ca.us)
       Cosysop - Threat Management Institute BBS 707 935 1713