;first, clean registers
;second, load x4002 into a register
;third, determine if negative or positive
;fourth depending on what it is, add it to memory location
;stop when reaching a memory location of zero
            .ORIG x3000             ;start point
            
            AND R6, R6, #0          ;clean R6
            AND R5, R5, #0          ;clean R5
            AND R4, R4, #0          ;clean R4
            AND R3, R3, #0          ;clean R3
            STI R3, NEGATIVEPOS     ;clean memory at location
            STI R3, POSITIVEPOS     ;clean memory at location
            
            
LOOP        LD R6, POSITION         ;load position into register
            ADD R6, R6, #1          ;Add one to register
            ST R6, POSITION         ;Store new value in memory
            LDI R3, POSITION        ;Load from new value
            ADD R3, R3, #0          ;test for negative
            BRz DONE                ;Halt if result is zero
            BRn NEGATIVE            ;Branch if negative
            BRp POSITIVE            ;branch if positive
            
NEGATIVE    LDI R4, NEGATIVEPOS     ;load negatve total into r4
            ADD R4, R4, R3          ;add stored value together with new value
            STI R4, NEGATIVEPOS     ;store the new total back to negative total
            BR LOOP                 ;loop back
            
POSITIVE    LDI R5, POSITIVEPOS     ;load positive total into r5
            ADD R5, R5, R3          ;add stored value together with nuew value
            STI R5, POSITIVEPOS     ;store the new total back into positive total
            BR LOOP                 ;loop back
DONE        HALT                    ;kill program
POSITIVEPOS .fill x4000
NEGATIVEPOS .fill x4001
POSITION .fill x4001
.END