IBM System/370 145 Operating Procedures Manual page 24

KEY
FUNCTION
Resets all machine check circuitry and POWER and THERM
CHECK RESET
indicators.
START CONSOLE
Starts a console-file read operation.
FILE
CONTROL
For service personnel; described in maintenance documentation.
ADDRESS SET
ENABLE SYSTEM
With SYSTEM RESET or LOAD key, clears main
CLEAR
storage. (See "Clear Storage:'page 58.)
SETIC
Loads the contents of rotary CDEFGH into the instruction
counter. Instruction processing starts from this address.
DISPLAY
Displays main store, general registers, and floating-point
registers. (See "Manual Store/Display Operations:'page 61.)
STORE
Stores information into main storage or registers. (See
"Manual Store/Display Operations," page 61.)
Resets CPU circuitry. Turns on the IMPL REQD indicator
and executes system reset and resident diagnostic micro-
programs to check CPU hardware.
SYSTEM R ESET*
Any error detected by system reset turns on the DIAGN
STOP indicator. A successful system reset turns off the
IMPL REQD indicator and places the system in a soft-stop
awaiting your action.
Stores the contents of tho current PSW in locatIons 8-15 and
RESTART
loads the doubleword starting at address 0 as the current PSW.
The channels are not resot and processing starts under control
of the PSW.
START
With the rotary switches in the normal or PROCESS positions,
initiates CPU processing.
Soft-stops the CPU when the current instruction and pending
STOP
interrupts are completed. The instruction counter is displayed
in the A-REGISTER DISPLAY indicators while the CPU is in
the soft-stopped state.
INTERRUPT
Requests an external interrupt. The interrupt is taken if
programmed and allowed by the system mask.
LOAD**
Starts an IPL operation.
POWER ON Initiates a power-on sequence.
POWER OFF I nitiates a power-off sequence.
*The control registers and PSW contents remain unchanged.
**The control registers are set to their initial state, and the PSW is set to all zeros
with valid parity.
System Control Panel Indicators, Switches, and Keys 23
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