IBM System/370 User Manual

System/370 Model 155 (cont'd)
ALTER/DISPLAY CHART
STORAGE
ALTER DISPLAY
ADDRESS
AREA
MNEMONIC MNEMONIC
RANGE
MAIN STORAGE AM
DM
OOOOOO-FFFFFF
GENERAL-PURPOSE
AG -
DG O-F
REGISTER
FLOATING-POINT AF
DF
0,2,4,6
REGISTER
CURRENT PSW AP
DP
NONE REQUIRED
CONTROL REGISTERS AC
DC
O-F
To Alter Registers, PSW, and Main Storage
1_ Press the CPU STOP key (machine in manual state).
2. Press the ALTER/DISPLAY key.
3. Wait for both AL T/DISP MODE and PROCEED to turn on.
4. Select the 2-character mnemonic {A plus the appropriate second letter! from
the Alter/Display chart, and type the mnemonic and the address of the
information to be altered.
5. Enter data, using the space bar to skip over positions not being altered. The
data in the skipped-over positions remains unchanged and prints out each
time the space bar is operated.
6. To end tne aiter operation, press the ALTEl'liOISPLAY key or END key. If
you press the ALTER/DISPLAY key, the PR-KB remains in alter/display
mode. If you press the END key, alter/display mode is terminated.
To Stop on Main Storage Address
1. Press the STOP key (machine in manual state).
2. Set STORAGE SELECT switch to MAIN.
3. Set ADDRESS COMPARE switch to ANY.
4. Set the address of the desired storage address in console switches CDEFGH.
5. Set the ADDRESS COMPARE (SAR) toggle switch to STOP.
6. Press the START key.
To Clear Storage
1. Hold down the ENABLE SYSTEM CLEAR key.
2. Press the SYSTEM RESET or LOAD key. All of main storage including the
storage protect key5 will be cleared to zeros.
Hard Stop Option
The HARD STOP switch is used with operating systems that do nOT have the retry
facilities inherent in Model 155 hardware. At this setting, the machine stops when
parity/machine checks occur. After a hardstop, the operator should returp CHE:K
CONTROL to PROCESS, run the SEREP program, and save the results for the CEo
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IBM System/370 Specifications

General

Brand	IBM
Model	System/370
Category	Server
Language	English