Sharp MZ-3500 User Manual download pdf (Page 48)

M Z 3500

Example 2: CE330S (light passing through the notch

is sensed and decoded as write protect)

(Double side, Double density)

Write enabled

Light IS interrupted by the label

Write protected

- inhibit notch

Two types of write protection are used and attention

must bepaid to the presience of the label because it may

cause a wrong result if the label is used improperly.

5) Media recording methods

Two recording methode are used:

• FM method (Single density)

This method is called the freqency modulation (FM)

or double frequency (DF). Clock and data are written

on the media which requires that a clock bit that

precede the data.

JLJLJl

(C: clock, D; data)

Waveforms of data written or read in the FM mode are shown below.

C D

Write data

(WD)

Write current

Residual magnetic

flux on the media

Read waveform

Differentiate

waveform

Shaped waveform

Read data (RD)

Write current; The write data is input to the flipftop and

is inverted each time a pulse is received to change the

direction of writing current.

at a change of magnetic flux. The waveform is than

shaped to obtain read data identicil t-j tlie write data.

Data cycle will be 4/js.

- .=).^ -

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Sharp MZ-3500 User Manual Page 48