org $1500 ; starting address of the program ldd $1002 ; place the lowest two bytes of the first operand in D addd $1006 ; add the lowest two bytes std $1012 ; save the sum of the lowest two bytes ldaa $1001 ; place the second-to-most-significant byte of the ; first operand in A adca $1005 ; add the second-to-most-significant byte of the ; second operand and carry to A staa $1011 ; save the sum of the second-to-most significant ; bytes ldaa $1000 ; place the most-significant byte of the first operand ; in A adca $1004 ; add the most-significant byte of the second ; operand and carry to A staa $1010 ; save the sum of the most-significant bytes end