The contents of the accumulator are ORed, bit by bit, with the contents of the addressed core-storage location. The result replaces the contents of the accumulator. ORing occurs only between corresponding bit positions in the accumulator and the core-storage word: bit 0 is ORed only with bit 0, bit 1 only with bit 1, and so on. The four possible ORing results are:
|From Core Storage Word||From Accumulator||Result in Accumulator|
Contents of the addressed core-storage word are not changed as a result of the operation. An example of ORing is:
0011 0101 1111 1010 Word in accumulator OR 0101 0001 1010 0000 Word from core storage 0111 0101 1111 1010 Result in accumulator
There are no addressing exceptions for the logical OR instruction; all forms of addressing that are described under "Effective-Address Generation" apply to the OR instruction.
Indicators: The carry and overflow indicators are not affected during the OR operation.
Programming Note: A common use of the OR instruction is in setting a particular bit to the on (1) condition.
XXXX XXXX XXXX XXXX Word in accumulator OR 0000 0010 0000 0000 Mask in storage XXXX XX1X XXXX XXXX Result in accumulator
|Assembler Language Coding||Hexadecimal Value||Description of Instruction|
|OR||DISP||E8XX||OR contents of CSL at EA (I+DISP) with A|
|OR||1||DISP||E9XX||OR contents of CSL at EA (XR1+DISP) with A|
|OR||2||DISP||EAXX||OR contents of CSL at EA (XR2+DISP) with A|
|OR||3||DISP||EBXX||OR contents of CSL at EA (XR3+DISP) with A|
|OR||L||ADDR||EC00XXXX||OR contents of CSL at EA (Addr) with A|
|OR||L||1||ADDR||ED00XXXX||OR contents of CSL at EA (Addr+XR1) with A|
|OR||L||2||ADDR||EE00XXXX||OR contents of CSL at EA (Addr+XR2) with A|
|OR||L||3||ADDR||EF00XXXX||OR contents of CSL at EA (Addr+XR3) with A|
|OR||I||ADDR||EC80XXXX||OR contents of CSL at EA (V in CSL at Addr) with A|
|OR||I||1||ADDR||ED80XXXX||OR contents of CSL at EA (V in CSL at "Addr+XR1") with A|
|OR||I||2||ADDR||EE80XXXX||OR contents of CSL at EA (V in CSL at "Addr+XR2") with A|
|OR||I||3||ADDR||EF80XXXX||OR contents of CSL at EA (V in CSL at "Addr+XR3") with A|
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