Systems Reference Library - All about the IBM 1130 Computing ...

DATA FLOW DISPLAYSSix rows of lights and two rotary switches (Figure29) facilitate the display of data flow in the P-C.Address RegisterThese 16 lights display the data in the storage addressregister (SAR) or the selected channel addressregister (CAR), depending on the position of thedisplay address register switch. The selected registeris displayed each time the P-C comes to astop or wait condition. (The clock will be at 7.)register (XR1, XR2, or XR3), or the shift counter(SC), depending on the position of the display dataregister switch. The selected register is displayedeach time the P-C comes to a stop or wait condition.(The clock will be at 7.)Display Data Register SwitchThis five-position rotary switch is used to select theQ-register, an index register, or the shift counterfor display in the data register.DISPLAY PROCEDURESDisplay Address Register SwitchThe 16-position rotary switch is used to select aCAR or SAR for display in the address register.Permanent Register Displays: I, B, D, and AThe contents of these four registers are always displayed.Data Register 4.These 16 lights display the contents of the Q-regis- 5.ter, which is the A-register extension, the index 6.The following procedure may be used to display corestorage data between the execution of single instructions:1.2.3.With P-C in stop condition, position mode switchto SI (single instruction).Press START successively to get program todesired point for data display.Record address in I-register. (Because I-registeris used in display mode, this recordedaddress is needed to return P-C to next instruction.)Set address of core storage word to be displayedinto data entry switches.Position mode switch to LOAD.Press LOAD I.ADDRESS REGISTERI REGISTERB REGISTERD REGISTERA REGISTERDATA REGISTER••••••••12 13 14 1512 13 14 15• •••••••••••••••0 2 3 4 5 6 7 8 9 10 II 12 13 14 15• • •••••• ••••••••••••••••• ••••••••0 I 2 3 4 5 6 7 8 9 10 II12 13• • ID••••• ••••••••14 150 I 2 3 4 5 6 7 8 9 10 II• • ••••••0 I 2 3 4 5 6 7 8 9 10 II0 I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 00 I 2 3 4 5 6 7 8 9 10 II 12 13 14 15• • ••••••••••••••SARDISPLAYADDRESS REGISTERCAR 0CAR ICAR 2CAR 14C ARCAR 3CAR 13 CAR 4CAR12 ------, ,,,, 5CAR I I -'7/ \\" CAR 6CAR 10 CAR 7CAR 9 CAR 8XR2XR IDISPLAY DATA REG!: TERXR3SC1742081Figure 29. Console Data Flow Displays88