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

The processor does not recognize interruption requests while it is in the stop state, but therequests are not lost. They are stacked and become pending, to be serviced when processingis resumed. The operator console functions can be used provided they are enabled by theconsole controls switch. When the start key is pressed, the processor exits from the stopstate and returns to the state that was left when it entered the stop state. However, if thestop state is entered under control of the check control switch (stop on error), the systemmust be reset by the reset key in order to remove the error condition.In the stop state the interval timers, if already running, continue to run.Manual Wait StateThe processor enters the manual wait state and turns on the stop light and wait lightwhen either of the following occurs:• The System/7 power-on sequence is performed.• The reset key on the operator console is depressed.While in the manual wait state, no interruption requests are recognized by theprocessor. The processor can exit from this state when the stop, IPL, or start key on theoperator console is depressed. When the start key is depressed, the processor beginsprogram execution on the lowest priority level (level 3) at the storage location specifiedby the IAR.Wait StateThe processor enters the wait state and turns on the wait light whenever the level exit(PLEX) instruction is executed and no other interruption request is pending. While inthe wait state, the processor will recognize interruption requests, depending oninterruption controls set by the program.The processor exits from the wait state when the stop, IPL, or reset key on the operatorconsole is depressed, or when an interruption request requires service. Depression of thestart key has no effect when the processor is in the wait state.Load StateThe processor enters the load state and turns on the load light when any of thefollowing occurs:• The program load key on the operator console is depressed.• The automatic restart function is operating.• A host processor signals the System/7 that an IPL operation is to be performed.The processor is in the load state only during the IPL operation. (See program load(IPL) descriptions in Chapters 5, 7, 8, 9, 15 and/or "EIPL" in Chapter 16.)IBM 5010 Processor Module 2-5