Explanations, 60 explanations – Sony MZ-R410 User Manual
Page 60
 
60
Explanations
How the MiniDisc got so small
The 2.5-inch MiniDisc, encased in a plastic 
cartridge that looks like a 3.5-inch diskette 
(see illustration above), uses a new digital 
audio compression technology called 
ATRAC (Adaptive TRansform Acoustic 
Coding). To store more sound in less space, 
ATRAC extracts and encodes only those 
frequency components actually audible to 
the human ear.
Quick Random Access
Like CDs, MDs offer instantaneous random 
access to the beginning of any music track. 
Premastered MDs are recorded with location 
addresses corresponding to each music 
selection.
Recordable MDs are manufactured with a 
“User TOC Area” to contain the order of the 
music. The TOC (Table of Contents) system 
is similar to the “directory management 
system” of floppy disks. In other words, 
starting and ending addresses for all music 
tracks recorded on the disc are stored in this 
area. This lets you randomly access the 
beginning of any track as soon as you enter 
the track number (AMS), as well as label the 
location with a track name as you would a 
file on a diskette.
The meaning of “no sound”
“No sound” describes a recorder condition in 
which the input level is about 4.8 mV during 
analog input or less than –89 dB during 
optical (digital) input (with 0 dB as full bit 
(the maximum recordable level for a 
MiniDisc)).
Note on digital recording
This recorder uses the Serial Copy 
Management System, which allows only first-
generation digital copies to be made from 
premastered software. You can only make 
copies from a home-recorded MD by using the 
analog connections.
B
A
B
— Music Data
A
— User TOC Area
Contains the order and start/end 
points of the music.
Premastered software such 
as CDs or MDs.
Digital recording
Home-
recorded 
MD
No 
digital 
recording
Recordable 
MD