; PBlazIDE Homework #1 ("Add all and subtract all" program)
; By Rory Johnson

start:
                    LOAD      s0, 0			; Number #1 to be added
                    LOAD	  s1, 0			; Number #2 to be added

addall:						  	   	   	    ; Outer add loop:

                    CALL	  addloop	   	; Add to all possible numbers the current value of Number #1...
                    ADD       s0, 1		  	; ...then increment Number #1.
                    COMP 	  s0, 0		  	; See if Number #1 has already had the values of all eight-bit hex values and looped back to zero
                    JUMP      NZ, addall	; If not, repeat
                    JUMP	  suball		; If so, start subtracting numbers
                    
addloop:					  			   	; Inner add loop:

					LOAD	  s3, s0		; Add first number
					ADD		  s3, s1		; Add second number and compute the result
					STORE	  s3, 0			; This location does something to the result and can be changed
					ADD		  s1, 1			; Increment Number #2
					COMP	  s1, 0			; See if Number #2 has had the value of all possible 8-bit hex values
					JUMP	  NZ, addloop	; If not, repeat
					RET						; If so, jump back to the outer loop, increment Number #1 by one, then

suball:				   		  	  		   	; Outer subtract loop:

	   				CALL	  subloop		; Subtract the current value of Number #1 from all possible numbers...
	   				ADD	  s0, 1				; ...then increment Number #1.
	   				COMP	  s0, 0			; See if Number #1 has already had the values of all eight-bit hex
	   				JUMP	  NZ, suball	; If not, repeat
	   				CALL	  fin			; If so, jump to end
	   				
subloop:					  	  		    ; Inner subtract loop:

					LOAD	  s3, s0		; Add first number
					SUB	  s3, s1			; Add second number and compute the result
					STORE	  s3, 0			; Again does something to the result, again can be changed
					ADD	  s1, 1	  			; Increment second number by one
					COMP	  s1, 0			; See if Number #2 has had all eight-bit hex values
					JUMP	  NZ, subloop	; If not, repeat
					RET			  			; If so, jump back to the outer loop and increment Number #1 by one
					
fin:				JUMP fin  				; Loop endlessly. The rest of the real program would be executing now.