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System-Reset-Clear Key
Activating the system-reset-clear key causes a
clear-reset operation to be performed. For details,
see the section "Resets" in Chapter 4, "Control."
The system-reset-clear key is effective when the
CPU is in the operating, stopped, load, or
check-stop state.
System-Reset-Normal Key
Activating the system-reset-normal key causes a
program-reset operation to be performed. For
details, see the section "Resets" in Chapter 4,
"Control. "
The system-reset-normal key is effective when
the CPU is in the operating, stopped, load, or
check-stop state.
Test Indicator
The test indicator is on when a manual control for
operation or maintenance is in an abnormal
position that can affect the normal operation of a
program.
Setting the address-compare controls or the
check control to stop or setting the rate control to
instruction step turns on the test indicator. Setting
the interval-timer control to disable mayor may
not turn on the test indicator.
The test indicator may be on when one or more
diagnostic functions under the control of
DIAGNOSE are activated, or when other abnormal
conditions occur.
Operation Note
If
a manual control is left in a setting intended for
maintenance purposes, such an abnormal setting
may, among other things, result in false
machine-check indications or cause actual machine
malfunctions to be ignored.
It
may also alter other
aspects of machine operation, including instruction
execution, channel operation, and the functioning
of operator controls and indicators, to the extent
that operation of the machine does not comply with
that described in this publication.
TOD-Clock Control
When the TOD-clock control is not activated, that
is, the control is set to secure, the value of the
time-of-day (TOD) clock is protected against
unauthorized or inadvertent change by not
permitting the instruction SET CLOCK to change
the value.
When the TOD-clock control is activated, that
is, the control is set to enable set, alteration of the
clock value by means of SET CLOCK is permitted.
This setting is temporary, and the control
automatically returns to secure.
Wait Indicator
The wait indicator is on when the wait-state bit in
the current PSW is one.
Chapter 13. Operator Facilities
13-5
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