What Is An Md (Mini Disc) - Aiwa XR-MD90 Operating Instructions Manual

WHAT IS AIM MD (MINI DISC)?
THE LIMITATIONS OF MD
An MD is only 64 mm (2 5/8 in.) in diameter, about half the size of
a conventional CD. But an MD can be used to store and playback
a full 74 minutes of data such as a CD, Unlike a CD, MD comes
in a [plastic cartridge, so that it can be handled with ease, The
cartridge also protects the disc inside from shocks, dust and
scratches. Unlike cassette tapes, which can become stretched
or tangled, an MD is an excellent durable media.
TYPES OF MDS
Thers are two types of MDs: "Optical discs" and "Magneto-optical
discs". Both types use laser beams and optical pick-up
technology to read recorded data during playback,
Optical discs
These are playback only discs. Like CDs, they are used as
prerecorded music discs. You cannot record or edit them.
El
Label
The shutter covers
the opening only on
the non-labeled
side of the MD.
Recordable MO*l discs
These are recordable discs which can be recorded on again
and again, like cassette tapes. The recording method called
magneto-optical technology employs a laser and magnetism to
record signals, Therefore, the quality of recorded sound does
not cleteriorate even after many playbacks and recordings.
4
m
l+-
Label
The
shutter covers
the opening on both
sides of the MD.
*1 MO: An abbreviation of Magneto Optical
lfltri~ compact size made possible by ATRAC*2
technology
A newly developed digital audio compression technology called
the ATRAC system automatically extracts only the frequencies
that are actually audible to the human ear and cuts the
frequencies which are inaudible. This compresses the amount
of data to be recorded to 1/5 of the normal amount. The ATRAC
system is based upon studies carried out in the field of auditory
psychology and does not impair the quality of the audible sound.
'2 ATRAC: An abbreviation of Adaptive TRansform Acoustic
Coding
Quick random access
One of the great features of the MD is that you can search for
desired tracks quickly. There are also quick and easy functions
for random playback, in which the order of the tracks can be
rearranged at random, and for renumbering tracks enabling them
to be played in any order.
Recording on the MD is performed differently from that of a
cassette tape or a DAT. Therefore, the MD system is subject to
the following restrictions.
"TOC* Full" is displayed even if the recording time
does not reach the maximum recordable time of the
disc (60-minute
or 74-minute).
"TOC Full" is displayed when 254 tracks are already recorded
on a disc, without respect of the recording time.
*TOC: An abbreviation of Table Of Contents.
"TOC Full" is displayed even if a disc is not fully
recorded on.
If there are lots of emphasis data in a particular track, the unit
handles the data as index codes, and tracks are counted, in
addition, without respect of the time and number of tracks.
The remaining time on a disc is not increased even
after some short tracks have been erased.
When the remaining time on a disc is displayed, which may not
be increased even after erasing short tracks because the sections
less than eight seconds are not counted.
Tracks cannot be joined (the COMBINE function does
not function).
Tracks created by editing may not be joined,
The total of the recorded time and the remaining time
on a disc does not match with the maximum
recordable time of the disc (60-minute or 74-minute).
Recording is performed by the minimum unit of one cluster (two
m
seconds). Even if the recorded section is shorter than two ,
seconds, a two-second space is needed in recording. Therefore, '
the available time becomes shorter. If there are scratches on a
disc, the available time becomes shorter as well, because the
sections which are scratched are automatically erased,
Track numbers may not be registered properly.
When recording from a CD through digital inputs (using the CD
- MD button), small tracks may be created depending on the
contents of a CD.
When using the AUTO MARK function, track numbers may not
be registered properly depending on the contents of the CD.
Digital inputs may not be acceptable.
When digital recording is attempted from recorded material with
copyrights, digital dubbing cannot be performed to a recordable
MD from another MD recorded in digital, because of the built-in
record restriction function which complies with the SCMS*
standard,
* SCMS (Serial Copy Management System) is the standard to
restrict single digital dubbing between the digital audio system
thus protecting copyrights.
(prerecorded"s%und source)
Digital dubbing
Pl:'"g EU9E9
ENGLISH 13