1. xerox 560 computer system - The UK Mirror Service

2 3 4 Result of ShiftCircular Shift, Double Register- a No overflow on left shift.- Overflow on left shift.Searching shift terminated with Ra equal to 1.At the completion of right shifts, the condition code is setas follows:a a2 3 4If the shift count, C, is positive, the contents of registers Rand Rul are shifted left C places. Bits shifted past bitposition a of register R are copied into bit position 31of reg i ster Ru 1. (No bi ts are lost.) If Cis negati ve, thecontents of registers Rand Rul are shifted right lei places.Bits shifted past bit position 31 of register Ru1 are copiedinto bit position 0 of register R. (No bits are lost.)Affected: (R), (Rul), CC1, CC2Logical Shift, Single RegisterArithmetic Shift, Single RegisterIf the shift count, C, is positive, the contents of register Rare shifted left C places, the O's copied into vacated bitpositions on the right. (Bits shifted past RO are lost.) If Cis negative, the contents of register R are shifted right Iciplaces, with O's copied into vacated bit positions on theleft. (Bits shifted past R31 are lost.)Affected: (R), CC1, CC2Logical Shift, Double RegisterIf the shift count, C, is positive, the contents of register Rare shifted left C places, with O's copied into vacated bitpositions on the right. (Bits shifted past RO are lost.) If Cis negative, the contents of register R are shifted right leiplaces, with the contents of bit position a copied into vacatedbit positions on the left. (Bits shifted past R31are lost.)Affected: (R), CC1, CC2Arithmetic Shift, Double Registernr£.,Jo 1 2If the shift count, C, is positive, the contents of registersRand Ru1 are shifted left C places, with O's copied intovacated bit positions on the right. Bits shifted past bitposition a of register Ru1 are copied into bit position 31of register R. (Bits shifted past RO are lost.) If C is negative,the contents of registers Rand Ru1 are shifted rightIci places with O's copied into vacated bit positions on theleft. Bits shifted past bit position 31 of register Rarecopied into bit position a of register Ru 1. (Bits shiftedpast Ru 131 are lost.)Affected: (R), (Ru1), CC1, CC2Circular Shift, Single RegisterIf the shift count, C, is positive, the contents of register Rand Rul are shifted left C places, with O's copied into vacatedbit positions on the right. Bits shifted past bit positiona of register Ru1 are copied into bit position 31 ofregister R. (Bits shifted past RO are lost.) If C is negative,the contents of registers Rand Ru1 are shifted right Iciplaces, with the contents of bit position a of register Rcopied into vacated bit positions on the left. Bits shiftedpast bit position 31 of register R are copied into bit positiona of register Ru1. (Bits shifted past Ru131 are lost.)Affected: (R), (Rul), CC1, CC2Searching Shift, Single RegisterIf the shift count, C, is positive, the contents of register Rare shifted left C places. Bits shifted 'past bit position 0are copied into bit position 31. (No bits are lost.) If Cis negative, the contents of register R are shifted rightlei places. Bits shifted past bit position 31 are copiedinto bit position O. (No bits are lost.)Affected: (R), CC1, CC2The searching shift is circular in either direction. If theshift count, C, is positive, the contents of register Rareshifted left C bit positions or unti I a 1 appears in bit positionO. If C is negative, the contents are shifted right Icipositions or unti I a 1 appears in bit position O. When theshift is terminated, the remaining count is stored in register1, which is dedicated to the searching shift instruction.Shift Instructions 71