ORG 100h 
MOV AX, a           ;Set AX to 'a' variable
MOV CX, 712h        ;Set CX to 712h 
MOV DS, CX          ;Copies value of CX into DS
MOV SI, 25          ;Set SI to 0019 (decimal value of 25)
MOV [105], 6Ah      ;Sets memory address 02712:0069 to 6Ah
MOV 25[BP][SI], AX  ;PA=SS(Shifted left)+a+BP+SI
                    ;Copy data from AX to physical address(PA)
MOV DL, [BX]+6      ;Load data from PA=DS(Shifted left)+BX+6 to DL
RET                 ;stops the program

a DW 5C21h