The five instructions of 8086 microprocessor and their operations will be as follow:

1. MOV AL, BL ; AL $\leftarrow$ BL

copy byte from (BL) Register to (AL) Register.

2. ADD AX , BX ; AX $\leftarrow$ AX + BX

Add 16 bit word from AX with BX and store result in AX.

3. MOVSB ; DS : [ S I ] $\rightarrow$ ES : [ D I ]

This instruction moves a string byte from memory location DS : [SI] to memory location ES : [DI].

4. STDSB ; (AL) $\leftarrow$ ES : [ D I ]

This instruction stores a string byte from accumulator (AL) into memory location ES : CD

5. LAHF ; (AH) $\leftarrow$(flag LB)

This instruction loads (AH) register with lower byte of flag register.