Clear Storage; Data Compare Trap; 3210 Model 2 Printer-Keyboard; System Check Error Recovery - IBM System/370 145 Operating Procedures Manual

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CLEAR STORAGE
Main storage can be cleared to zeros by the following pro-
cedure.
1.
Hold the ENABLE SYSTEM CLEAR key in the operated
position.
2. Press the SYSTEM RESET or LOAD key.
All of main storage is cleared to zeros; control storage is not
affected.
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DATA COMPARE TRAP
1. Press the STOP key.
2. Set the ADDRESS COMPARE switch to the DATA
COMPARE TRAP position.
3. Set the address of the storage byte location being mod-
ified in console switches CDE FG H.
4. Set data switches A and B to the desired byte match
value.
5. Set the ADDRESS COMPARE CONTROL toggle
switch to the STOP position.
6. Press the START key.
When a store operation modifies the specified storage byte
location to the value set in switches A and B, the ADR
COMP MATCH indicator is turned on and the CPU enters
a soft-stop state. The instruction counter is displayed in
the A-REGISTER DISPLAY roller switch indicators.
To determine the address of the instruction that modified
the storage byte, subtract the current instruction length code
(located in the current PSW) from the value in the instruc-
tion counter .
• 3210 MODEL 2 PRINTER-KEYBOARD
The 3210 Model 2 console functions the same as the con-
sole PR-I<B for data entry and wri.te operations. However,
alter/display functions are not allowed.
A line switch is provided for turning on and turning off
power.
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SYSTEM CHECK ERROR RECOVERY
If a system check indicator is on, re-IMPL and re-IPL. If
errors continue, record the indicators and notify your
service representative.
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