Manual Controls - IBM 7090 Instruction-Reference

6. 1. 02 Manual Controls
Figure 6.1-1 shows the keys and switches on the operator's panel that provide for
starting and stopping the machine and initiating computer functions. All keys are of the
spring-returned variety with the exception of the auto-manual key, entry keys, sense
switches, and emergency-off key.
Power-On
With the system in normal-off
~tatus,
pressing the power-on key will commence the
power-on sequence. Ready status (power-on) will be reached in about 20 seconds. As
power comes on, a clear operation is performed, resetting all registers and triggers,
and setting memory to all zeros.
Normal-Off
The normal-off key will initiate the following:
1. Immediate removal of 60-cycle power from the MG set, MG blower, and all
frame blowers except memory.
2. Immediate removal of 400-cycle power from the 30-60 volt memory power supply.
3. After 5 seconds, removal of 400-cycle power from the standard memory supply.
4. After 3 minutes, removal of power from the memory blowers.
The dropping of the 60-cycle power removes the input to the MG, but the MG still
rotates at about full speed for longer than 5 seconds, allowing the memory power to
sequence down.
Emergency-Off
When the emergency-off switch is pulled, all power is immediately removed from
the 7090 system, except the voltage to HR 24 and HR 30 points in the power control unit.
The emergency-off switch is to be used only in emergencies, because of possible dam-
age to circuits.
Resets
The reset circuits control the resetting of various components in the system.
There are three types of resets which may be initiated from the panel.
An interlock reset is initiated by the load keys, clear key, and
power-on key.
It
causes the resetting of all registers (except
sense indicator), panel light (except power on and ready), all
channels that are in operation and their associated registers.
An operator's reset is initiated by the reset key.
It
performs all the
functions of an interlock reset plus a bias reset for CPU triggers.
A power-on reset occurs when power is applied to the system. This
reset accomplishes an interlock reset, an operator's reset, plus the
resetting of the clock and setting core storage to all zeros. The clear
key also initiates a power-on reset if the machine is in automatic
status.
Automatic - Manual Key
The auto-manual switch controls the rest of the switches on the console. If a pro-
gram is running in automatic status, and the switch is put in the manual position, the
program will stop after it completes the operation it is performing. If an
1-0
program
is running,
1-0
will complete the operation before stopping. The auto-manual switch
will not affect the program stop status.
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