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

The switches, keys, and lights needed to operate and control the System/7 are arrangedon the operator console of a three- or six-position main enclosure as shown in Figure 5-1.The descriptions in this chapter also apply to the console on the two-position enclosure,even though the switches, keys, and lights are arranged slightly different from Figure 5-1.The system design minimizes the need for operator use of the console. A key switchgives added security from unauthorized use of the system by disabling the console. Thus,only authorized persons can enable the console by using the key switch.The main functions of the operator console are to turn power on and off, reset thesystem, load the initial program information, and store or display information in storageor registers. Additional facilities exist for program debugging and hardware testing.CONSOLE DISPLAY AREAIndicator lights in the console display area (see Figure 5-2) may appear to be on duringsystem operation. They are actually turning on and off at a rapid rate as a result of theinternal speed of the processor. Therefore, data represented by indicators (except the testlight) in the console display area is valid only when the processor is in the stop state.REG I LEVEL0 1 2 0 1 2,- 30 0 0 0 0 0 0I MCKIF1 El E2 OVRREQ REQ REQ CRY FLW SKP STP WT LD000 00 0000DATAPO I 0 1 2 3 4 5 6 7I P1 8 9 10 11010 0 0 0 0 0 0 0 0 0 0 0 0ADDRESS0 1 2 3 I 4 5 6 7 I 8 9 10 110 0 0 0 0 0 0 0 0 0 0 0PCKLS STG CU I/O INV INV INVPTY PTY CHK CHK SEQ OP ADR CT0 0 0 0 0 0 0 0TST012 13 14 150 0 0 012 13 14 150 0 0 0Figure 5-2. Console display areaREG LightsThe reg lights indicate, in binary notation, the index register being used by the currentinstruction. If all reg lights are off, the instruction either does not require an index registeror is using the accumulator or instruction address register, depending on the specificinstruction.LEVEL LightsThe level lights indicate which one of the four interruption levels (0, 1, 2, or 3) iscurrently active.Machine Check (MCK) Indicator LightsLS PTY (Local Store Parity) LightA parity error detected in one of the index registers turns on this indicator. A machinecheck interruption occurs if the check control switch is in the process position.STG PTY (Storage Parity) LightA parity error detected when data is read from storage turns on this indicator. A machinecheck interruption occurs if the check control switch is in the process position. (See`Parity' in Chapter 2, "IBM 5010 Processor Module.")Operator Console 5-3