IBM System/7 Functional Characteristics - All about the IBM 1130 ...

START KeyPressing the start key causes processing to resume on the same level that was active atthe time the machine was stopped. The amount of processing accomplished depends uponthe setting of the rate control switch. When the machine is in the manual wait state (boththe stop and the wait lights are on), pressing the start key causes the processor toactivate level 3 and begin program execution at the storage location specified by theIAR. Note that if the processor was in the wait or manual wait state and the machine wasstopped by depressing the stop key, depressing the start key causes the processor to returnto the wait or manual wait state.STOP KeyPressing the stop key stops the machine and turns on the stop light after completion ofthe current instruction.PROGRAM LOAD (IPL) KeyPressing this key resets the system as if the reset * key were depressed, and places theprocessor in the load state. The load light turns on and remains on for the duration ofthe IPL operation. The IPL data source must be specified by the load unit address switches(the two right-hand storage data/address switches) before the program load key is pressed.Data is transferred from the data source and stored in main storage starting at location0000. Upon completion of the IPL operation, the load light turns off, interruption level3 is activated, and instructions are executed beginning at location 0000. When instructionexecution begins, bits 10 to 15 of the level 3 accumulator will contain the load unitaddress, and bit 0 will be set off to indicate that the IPL operation was started by pressingthe IPL key, not by the auto restart function.Note: The program load key is inoperative if the host attachment switch is in the enableand IPL position.THERMAL LightThe thermal light indicates an overtemperature or undertemperature condition in theenclosure.POWER SwitchPlacing this toggle switch in the on position applies power to the power system andturns on the power-on light. In the off position, line power is removed and the power-onlight is turned off.CONSOLE CONTROLS SwitchWhen this switch is in the disable position, all console functions are disabled exceptthe power, host attach, and auto restart switches. A key must be inserted to turn theswitch to the enable position. The key cannot be removed unless the switch is in thedisable position.* See operating note under AUTO RSTRT switch description.pqmplolliapipplcipmenum!wmumir •