OR - OR Bitwise Instruction

The OR Instruction performs an OR action with the second operand on the first operand.

The first operand holds the result of this operation. All matching bits of 0 are retained, all other non-matching bits and 1's become 1.

However 2 memmory addresses cannot be used together.

This command has 3 parts, Instruction, then either operand can be a Register or Immediate value or a memory address.

Assembly
Sample Description 16 bit Machine
Code

OR AL, 0x03 ; 8 bit immediate number with AL 0C 03

OR AX, 0x0003 ; 16 bit immediate number with AX 0D 03 00

OR BL, 0x03 ; 8 bit immediate number with Register 80 C3 03

OR BX, 0x0003 ; 16 bit immediate number with Register 81 CB 03 00

OR [BX], 0x03 ; 8 bit immediate number with memory address 80 0F 03

OR [BX], 0x0003 ; 16 bit immediate number with memory address 81 0F 03 00

OR AL, BL ; 8 bit Registers 08 D8

OR BL, AL ; 8 bit Registers 0A D8

OR AX, BX ; 16 bit Registers 09 D8

OR BX, AX ; 16 bit Registers 0B D8

OR [BX], AX ; Register to memory address 09 07

OR AX, [BX] ; Memory address to Register 0B 07

OR [BX+2], AX ; Register to 09 47 02

OR AX, [BX+2] ; Memory address and offset to Register 0B 47 02

Assembly Sample	Description	16 bit Machine Code
OR AL, 0x03	; 8 bit immediate number with AL	0C 03
OR AX, 0x0003	; 16 bit immediate number with AX	0D 03 00
OR BL, 0x03	; 8 bit immediate number with Register	80 C3 03
OR BX, 0x0003	; 16 bit immediate number with Register	81 CB 03 00
OR [BX], 0x03	; 8 bit immediate number with memory address	80 0F 03
OR [BX], 0x0003	; 16 bit immediate number with memory address	81 0F 03 00
OR AL, BL	; 8 bit Registers	08 D8
OR BL, AL	; 8 bit Registers	0A D8
OR AX, BX	; 16 bit Registers	09 D8
OR BX, AX	; 16 bit Registers	0B D8
OR [BX], AX	; Register to memory address	09 07
OR AX, [BX]	; Memory address to Register	0B 07
OR [BX+2], AX	; Register to	09 47 02
OR AX, [BX+2]	; Memory address and offset to Register	0B 47 02