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

Example 2:PSKC instruction0 5 8 .9 1501Op code1 0 0I 111R• * •IIF1Conditions1 0 0 10 0 0 0Ili!!!Carry indicator 0Overflow indicator 1114 8 C 0The only test requested (bit 9 set on) is that both the carry and overflow indicators areoff. Since the overflow indicator is on, the test is false and no skip occurs.Example 3: In example 2, if the overflow indicator is off, the test requested istrue and the next word is skipped.Add to Storage and Skip (PAS)0 5 8 15Op code Rtill X0 1 1 1 1X X1 IDisplacement7 8-F X XThe add to storage and skip instruction (PAS) increments by 1 the contents of the storagelocation specified by the effective address. If the result in the storage location is a0 value, the one-word instruction that follows the PAS instruction is skipped. Sinceonly one word is skipped, this instruction should never be followed by a long-formatinstruction.The effective address is the algebraic sum of the contents of the displacement fieldand the register specified by R. If R=000, the IAR contents are used in thiscalculation.The carry and overflow indicators are not changed. The result indicators are changedto reflect the final contents of the addressed storage location.The PAS instruction can be used in conjunction with a storage word that is set up asa counter. Such counters are frequently set up and incremented each time a particularjob, function, or routine is accomplished. The counter value changing to 0 can be thecondition for termination of the routine and/or branching to another portion of theprogram. The add to storage and skip instruction (PAS) is used to increment the counterand then skip a storage word when the counter value becomes 0.Processor Instructions 4-39