Chapter 6, Problem 45E

Explanation of Solution

Assembly-language program:

The assembly-language program to read the three input variables “number1”, “number2”, and “number3” and to perform arithmetic operations on those numbers is as follows.

Symbol	Mnemonics	Operand	Comment
	BR	Main	; Branch to the location Main
number1:	.BLOCK	2	; Set up a two byte block for number1
number2:	.BLOCK	2	; Set up a two byte block for number2
number3:	.BLOCK	2	; Set up a two byte block for number3
result:	.BLOCK	2	; Set up a two byte block for result
Main:	DECI	number1,d	; Read and store number1
	DECI	number2,d	; Read and store number2
	DECI	number3,d	; Read and store number3
	LDA	number1,d	; Load number1 value into the accumulator
	ADDA	number3,d	; Add number3 to accumulator and store output into the accumulator
	SUBA	number2,d	; Subtract number2 from the accumulator and store output into the accumulator
	STA	result,d	; Store accumulator value into result
	DECO	result,d	; Write result value on the screen
	STOP		; Stop the processing
	...