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When
the
front
latch is
a diskette.
The diskette
Its
location is
ensured
stop
is
encountered and
opened, access is provided for
is
held
in
place by plastic
when
the diskette is inserted
the eJection mechanism latches.
insertion of
guide rails.
until a back
Closing
the
front
latch
activates
resulting in accurate
centering
and
drive hub is held at a constant speed
D.
C.
motor.
The head(s) remain in
until the front latch is opened.
the
cone
clamping
mechanism,
clamping
of the diskette.
The
of 300 RPM by a servo-controlled
contact with the recording media
The
heads
are
positioned over the desired track by means of a four-
phase
stepper
motor/band
assembly
and
its associated electronics.
This
positioner uses a one-step rotation to cause a one track linear
movement.
Data
recovery
differentiator,
data
decoding
electronics
include
a
low-level
read
amplifier,
zero crossover
detector, and digitizing circuits.
No
capabilities
are
provided.
The drive has the following sensors:
1.
A Track
°
sensor detects when the head/carriage assembly is
positioned at Track O.
2.
An index sensor is positioned to generate a digital signal
when an index hole on the diskette is detected.
The index
sensor distinguishes index and sector holes in a hard-
sectored diskette.
3.
A write protect sensor disables the write electronics when
a write protect tab is applied to the diskette.
4.
A motor control switch.
1.5
PHYSICAL DESCRIPTION
A
representative drive is
shown
in
Figure
1-1.
mounted in a vertical or horizontal plane.
However,
board
must
be
on the
uppermost
side
when
the
horizontally.
The drive can
be
the logic circuit
drive is mounted
The
spindle
is
belt
driven
by
a
D.
tachometer.
The
servo control
circuit
speed
of
the spindle.
C.
and
motor
with an integral
tachometer control the
The
read/write
mounted
to
a
ferrite/ceramic
hours.
head assembly is positioned by a split band positioner
stepper motor.
The read/write heads are glass-bonded,
structures with a life expectancy of 20,000 operating
Operator access for diskette loading is provided via a horizontal slot
located at the front of the drive.
The
electronic
components
of
the
drive are mounted on two printed
circuit boards.
The logic circuit board is mounted above the chassis.
The
motorcontrol
circuit
board
is
mounted
on
the
bottom of the
chassis.
Power
and
interface signals are routed through connectors
plugging directly into the logic circuit board.
1-3
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