MPI 40 Series - Page 93

6.4 SELECT DRIVE AND ENABLE STEPPER MOTOR WITHOUT LOADING
This option allows a seek operation without loading the heads when
the drive is selected. Using this option, the track position can be initia-
lized with a not ready condition in the drive. For read or write operations
the head must be loaded using the HEAD LOAD interface line (pin 18). If more
than one drive is assigned to the controller, separate I/0 pins should be used
as HEAD LOAD lines for each drive.
These unused I/O pins need to be connected to jumper-pin C3. This can be
accomplished by soldering a wire between the unused pin and C3. Pin 2, pin 6,
and pin 8 can be used to implement this option, however certain restrictions
will apply. Pin 8 is a spare, but pin 2 and pin 6 can also be used as an
external write current switch and external motor on respectively. When used
as a head load line its alternate function can not be implemented (refer to
paragraph 3.5.3).
To install this option on a standard drive, the following jumpers must be
added and deleted. Figure 6-5 illustrates this option.
A. Remove jumper L19 - 120
B. Remove jumper K9 - KlO
c. Install jumper K8 - K9
D. Install jumper C3 - C4 (On additional drives, remove jumper
C3 - C4 and solder a wire from the unused I/O pin to C3)
HEAD LOAD - 2 ....;
2
;..._--L
HEAD LOAD - 3 ....:6~-rc:::::;.,
HEAD LOAD-4 ~
8
~.-.-,1~~
Figure 6-5:
6-5
+DRIVE SELECT
KS
K9
+STEPPER ENABLE
+HEAD LOAD