Outline Of Fucntions; Read/Write Head; Track Positioning Mechanism; Spindle Drive Mechanism - Commodore 1540 Technical Manual

1.10
The drive can be briefly inspected for its operation by the
following proceedure. Install the drive, connect the power and I/O
cables. Turn drive on and make sure the front panel power lamp is
on. Proceed to step 2.2.
Outline of functions
The 1540/1541 Minifloppy Disk Drive mechanism is composed of the
data read/write head, track positioning mechanism, spindle drive
mechanism and eject mechanism.
1.11 Read/Write Head
The. Read/Write head uses a glass-bonded, ferrite/ceramic head.
Track-to-track erasing is accomplished by the straddle erase method.
The surface of the Read/Write head is mirror-ground to minimize
weear of the head and media. Also, the head is desighned in such a
way that the maximum signal can be obtained from the media surface.
1.12 Track positioning mechanism
Positioning of the Read/Write Head is accomplished by a stepping
motor and steel belt. The stepping motor rotates clockwise or
counter-clockwise by two steps per track. The control circuit on the
logic board selects the direction and number of step to the desired
track.
1.13 Spindle drive mechanism
The spindle drive motor operates on 12 VDC and turns the spindle,
through a belt drive, at 300 revolutions per minute. The speed of
the drive motor is controlled by a feedback signal from a tachometer
which is housed in the drive motor assembly. The feedback signal
controls a servo amp that supplies the 12 VDC drive current.
1.14 Eject mechanism
When the media is inserted in the Disk Drive and the door is closed
the media is clamped by the spindle and hub. At this time the
ejector mechanism is loaded by the insertion of the disk and locked.
When the door is opened, the ejector mechanism is unlocked and the
media pops out of the door.
3