Philips DAT850 - Manual (Page 12)

SCMS (Serial Copy Management System)
• SCMS controls the DAT’s serial copy with the digital signal.
It is possible for a SCMS-compatible DAT deck to record digital
sources including CDs, DAT prerecorded tapes, DSR (Digital
Satellite Radio) programs onto DAT tape with a direct digital input.
For sources such as CDs, DAT tapes and DSR programs
covered by SCMS regulations, copy-permitted programs can
be recorded on DAT tape whether or not they contain a copy-
prohibit code. When the copied (recorded) tape is played back
by a DAT deck and the digital output is input to the another
DAT deck, digital recording can be performed if there is no copy
prohibit code, however, digital recording cannot be performed
if there is a copy prohibit code. Namely, one — and only one
— copy can be made of a digital source with a copy prohibit
code, and second-generation, third-generation and serial
copying is not possible. SCMS applies in any DAT mode,
regardless the sampling frequency. The following illustrations
show the principles of the SCMS system.
• Copying digital sources
With copy prohibit code
Without copy prohibit code
DSR program
Digital microphone
First generation Second generation Third generation
Digital copy
---------------- ►
Whether there is the copy prohibit code or not
Separate AD converter
General category
(DSR program)
Digital copy
• Copying analog sources
When an analog signal is input, this signal can be recorded
by a DAT deck because this signal does not contain a copy
prohibit code. However, since the signal recorded on the tape
has passed through the A/D converter (ADC), the tape is
treated as a DAT prerecorded tape which contains the copy
prohibit code.
An A D converter performs sampling and quantization to convert
an analog signal into a digital signal. This signal processing
is called “A'D conversion" and the circuit which performs it
IS called an A D converter.
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