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DRAM and pins 43, 44, 45, and 46 of the MD LSI.
Record
1. The signals input from OPTICAL IN are input to pins 70 and 71 of
the MD LSI (IC3) via the buffer amp IC(IC401; input: pin 4,6 output:
pin 3,5)
2. The signals input to pins 70 and 71 of the MD LSI (IC3) are
converted to a sampling frequency of fs = 44.1 kHz by an fs
converter inside the LSI. If the signals are already fs = 44.1 kHz,
they bypass the fs conveter.
3. The signals converted to fs = 44.1 kHz or the signals input to pin
65 are ATRAC-encoded and stored in the DRAM (IC72).
4. The signals are sequentially taken from the DRAM (IC72) and sent
back to the MD LSI (IC3), where they are ACIRC-processed and
EFM-modulated and then output from pin 73 to the magnetic
head.
5. The magnetic disc records the signals onto the disc by
magnetizing the magnetic film on the surface of the disc. During
recording the laser diode emits its laser beam in order to raise the
temperature to the Curie temperature (*4) that is required to
magnetize the magnetic film. For this reason, the optical power of
the laser diode is higher during recording than during playback..
- Although the disc revolves at a speed fast enough to write
the signals without compression,the recording signals are
compressed in order to reduce the data volume. As a result,
the signals are written intermittently rather than continuously
(the recording signals are intermittently sent to the magnetic
head).
Control
1. performs the necessary controls for each operation during
playback and recording and for writting og the UTOC*
of recording.
- The information written in the UTOC includes the recorded
track numbers and their addresses, text data, etc..
at the end
5
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