Intel 80287, 80286 manual OR- Logical Inclusive or

THE 80286 INSTRUCTION SET

OR- Logical Inclusive OR

Opcode			Instruction		Clocks	Description
08	Ir		OR	eb,rb	2,mem=7	Logical-OR byte register into EA byte
09	Ir		OR	eW,rw	2,mem=7	Logical-OR word register into EA word
OA	Ir		OR	rb,eb	2,mem=7	Logical-OR EA byte into byte register
08	Ir		OR	rw,ew	2,mem=7	Logical-OR EA word into word register
OC	db		OR	AL,db	3	Logical-OR immediate byte into AL
00	dw		OR	AX,dw	3	Logical-OR immediate word into AX
80	11	db	OR	eb,db	3,mem=7	Logical-OR immediate byte into EA byte
81	11	dw	OR	eW,dw	3,mem=7	Logical-OR immediate word into EA word

FLAGS MODIFIED

Overflow=O, sign, zero, parity, carry=O

FLAGS UNDEFINED

Auxiliary carry

OPERATION

This instruction computes the inclusive OR of the two operands. Each bit of the result is 0 if both corresponding bits of the operands are 0; each bit is 1 otherwise. The result is placed in the first operand.

PROTECTED MODE EXCEPTIONS

#GP(O) if the result is in a non-writable segment. #GP(O) for an illegal memory operand effective address in the CS, DS, or ES segments; #SS(O) for an illegal address in the SS segment.

REAL ADDRESS MODE EXCEPTIONS

Interrupt 13 for a word operand at offset OFFFFH.

8-80