Operator Controls, 2311 - IBM 1800 Operating Procedures Manual

Figure 27. 2841 Switch
To allow a channel to be returned to the enabled state,
the following conditions must exist :
1. The enable/disable switch for that channel must be
in the enable position.
2. The processor-controller must be in the stopped or
wait state.
Note: If a 2841 with the two-channel switch
feature is
shared by two processors and one is to be powered down,
the corresponding enable/disable switch on the 2841 must
be placed in the disable position before turning off the
processor power.
OPERATOR CONTROLS, 2311 (Figure 28)
The Ready Light is the green light with the drive number
imprinted on it. It turns on when the 2311 is in ready
status an d able to access data. The following conditions
must exist before the ready light will turn on :
1. Cover closed.
2. Disk pack properly installed on drive .
3. START has been pressed an d cycle up sequence has
been completed.
The Select Lock Light,
when on, indicates a machine
condition which requires Customer Engineering attention .
This condition causes the disk storage drive to be disabled
and stops the usage meter. The condition can be reset by
turning the start/stop switch to STOP and then to START.
The Enable/Disable Switch
enables or disables communi-
cation between the 2311 and the 1800 system. It also
enables or disables the 2311 usage meter.
If the processor-controller is running when the switch
setting is change d, the 2311 status and usage meter status
remain unchanged until the processor-controller is placed
in the wait state .
Figure 28. 2311 Switches and Lights
The Start/Stop Switch, when moved to START, applies
power to the disk drive motor and initiates a cycle up
(start) sequence provided system power is on, a disk pack
is properly loaded, and the 2311 cover is closed. The
cycle up sequence consists of:
1. A delay of approximately 60 seconds while the disks
are being cleaned and coming up to speed.
2. The loading of the heads after the disks are cleaned
and up to speed.
3. An automatic seek to cylinder ODD.
4. The ready light turning on, indicating that the drive
is ready for use.
Moving this switch to STOP removes power from the
disk drive motor and initiates a cycle down (stop) sequence.
The cycle down sequence consists of:
1. Unloading of the heads and retraction of the access
mechanism from the disk pack.
2. A delay of approximately 30 seconds while the disk
pack stops.
IBM 2841 Storage Control and 2311 Disk Storage Drive
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