Here is the CSC-1 assembler code for the C version above:

   0:           LDI   2500   ; Put the address of the array into pointer
   1:           STD   POINTR
   2:           LDI   0      ; Put 0 into sum and i
   3:           STD   SUM
   4:           STD   I

   5:  LOOP:    LOD   MAX    ; is i == max?
   6:           SUB   I
   7:           JZ    ENDLOOP; if so, then we are done

   8:           LOD   POINTR ; Get pointer to current array element
   9:           A2S          ; Save in S to be used in indirect load
  10:           LDS          ; Actually fetch the value

  11:           ADD   SUM    ; Add current sum to this
  12:           STD   SUM    ; store back into sum

  13:           LOD   POINTR ; Add 1 to the pointer
  14:           ADD   ONE    ; so that it points to the next element
  15:           STD   POINTR ; for the next round of the loop

  16:           LOD   I      ; Add 1 to the counter
  17:           ADD   ONE    ; so we can know when we've looked at all
  18:           STD   I      ; the elements of the array

  19:           JMP   LOOP   ; Back to the top of the loop
  20:  ENDLOOP: HLT          ; When done, halt the computer

  21:  MAX:     NUM   5      ; maximum size of the array
  22:  I:       NUM   0      ; loop counter
  23:  ONE:     NUM   1      ; Constant 1 used to increment I

       =1000
1000:  POINTR:  NUM   0      ; a pointer to the current element of the array
       =1500
1500:  SUM:     NUM   0      ; will hold sum of all elements of array
       =2500
2500:  ARRAY:   NUM   8      ; The array of integer
2501:           NUM   2
2502:           NUM   1
2503:           NUM   4
2504:           NUM   6

Let's examine the heart of the while loop to see how indirect addressing is used.