subtraction

section .data
num1 db 8
num2 db 3
msg db "Sub: "
result db "0", 10
section .text
global _start
_start:
mov al, [num1]
sub al, [num2]
add al, '0'
mov [result], al
mov eax, 1
mov edi, 1
mov rsi, msg
mov edx, 5
syscall
mov eax, 1
mov edi, 1
mov rsi, result
mov edx, 2
syscall
mov eax, 60
xor edi, edi
syscall