read array and calculate average in assembly (asm)

readavg-nasm.as

section .data
array db 10, 20, 30, 40, 50      ; Declare an array with 5 elements
len equ $-array                  ; Compute the length of the array
avg db 0                         ; Declare a byte to store the average

section .text
global _start
_start:

mov ecx, len       ; Set up loop counter with number of elements
lea esi, [array]   ; Load effective address of array into ESI
xor eax, eax       ; Clear EAX to use as sum

sum_loop:
    add al, [esi]    ; Add current array element to sum
    inc esi          ; Move to next array element
    loop sum_loop    ; Loop until all elements have been processed

mov ecx, len       ; Load number of elements into ECX
idiv cl            ; Divide sum by number of elements

mov [avg], al      ; Store the average in 'avg'

; Exit
mov eax, 0x60     ; System call number (sys_exit)
xor edi, edi      ; Exit code
syscall           ; Call kernel

readavg-tasm.as

.MODEL small
.STACK 100h

.DATA
array DB 10, 20, 30, 40, 50 ; Declare an array with 5 elements
len EQU 5 ; Length of array
avg DW 0 ; To store average

.CODE
main PROC

    ; Initialize
    mov ax, @data
    mov ds, ax
    xor bx, bx ; bx will be used to store the sum
    xor si, si ; si will be used to index the array elements
    
    ; Sum all elements in the array
    mov cx, len ; loop counter
    sum_loop:
        mov al, array[si] ; load array element into al
        add bx, ax ; add it to the sum
        inc si ; go to next element
        loop sum_loop ; loop until all elements have been processed
    
    ; Divide the sum by the number of elements to get the average
    mov ax, bx ; move the sum into ax
    cwd ; Convert word to double word
    idiv byte ptr len ; Divide the sum by the number of elements to get the average
    mov avg, ax ; store the average

    mov ax, 4c00h ; terminate program
    int 21h

main ENDP
END main