Sharp FDD-412A - Page 27

FDD412A/B
(2) Outline of operation
Operation
flow
'
Condition
| |
Description
-
—-
—
--
—_-
ie
Ss
Command
from
FDC
WRITE
GATE-N
WRITE
DATA
Ae
Operation
mode
The
device
must
be
in
checked
in
FDD
1
ae
|
|
| 'FAULT' is set if the mode
ready state, with the | is not normal.
1
I
head engaged.
ERASE
GATE
(Timing
is
shown
The FDD generates a signal
generated
below.)
to operate the erase head.
Data written
i
Data and CRC data are
recorded.
WRITE
GATE-N
——
|
aif
d
1
4
T
'
ERASE
GATE-N
—————
;
=
—
_—
—1580
us
max.-—
200
us
TYP
Fig.
2.17
Outline
of
Write
Operation
(3)
Write
circuit
block
diagram
|
SELECT-N
Bees
:
FAULT
FILE PROTECT
+24V
Voltage
regulagor
Write
control
+15V
WRITE
GATE-N
Write
pattem
generator
WRITE DATA-N
LOW CURRENT-N
+5V power
supply check
ERASE
GATE
3
—
Erase
head
Fig.
2.18
Write
Circuit.
Block
Diagram
(4)
Circuit
operations
(a)
Write
pattern
generation
The FDC
modulates
data
in
the
FM/MFM
mode
and
sends
it
to
the
FDD
in
pulses.
The
FDD
converts
pulse
waveshapes
into
mag-
netic
head
current
waveshapes.