ACT apricot - Drive Switch Settings; Sensors and Detectors

DISK DRIVE
Sensors and Detectors
A series of photo-sensors and associated detector circuits
are fitted in the drive. These generate status output signals
to
the disk controller, on detecting the conditions detailed
below.
(a) A disk is within the drive (Ready).
(b) The disk is write protected (·....,W,....r-;.it....:.e~P~r-o-te-c-t').
(c) The head is positioned over Track 0 (Track 00).
(d) The start of each track (Index Pulse).
Drive Switch Settings
Two switches are located on the drive, which are set
according to the application of the drive within the system.
One switch (SW1) determines which of the two drive select
input signals switch the drive to an operational condition.
The second switch (SW2) determines the method of
switching
on the disk drive motor.
The drive select switch is located at the rear of the unit
(see Figure 4). In single disk drive systems, the switch is set
to drive position O. In dual drive systems, the left hand drive
(as viewed from the front of the System Unit) is configured
as Drive
0, and the right hand drive is configured as Drive 1.
The motor control switch is located on the circuit board
in the base of the'unit, just behind the front panel (see
Figure
4). The switch must be set to position B, so the disk
motor rotates only when a disk is within the drive. Setting
the switch to position A, will cause the disk motor to rotate,
regardless of whether a disk is within the unit or not.