Assembly prints wrong ascii character

Question

I was trying to create a simple assembly program that prints the ascii character whose binary code is in rax. I have the following code:

section .data
   res db '', 0

global _start
_start:
    mov rbx, 1000001
    mov [res], rbx
    
    mov rax, 1
    mov rdi, 1
    mov rsi, res
    mov rdx, 1
    syscall


    mov rax, 60
    xor rdi, rdi
    syscall

When I execute, it outputs 'A', which is correct since 1000001 is the binary code for ascii A, but if I execute this:

section .data
   res db '', 0

global _start
_start:
    mov rbx, 1000010
    mov [res], rbx
    
    mov rax, 1
    mov rdi, 1
    mov rsi, res
    mov rdx, 1
    syscall


    mov rax, 60
    xor rdi, rdi
    syscall

It outputs 'J', but according to the table I used 1000010 should output 'B'. What makes this even stranger for me is that if I use decimal instead of binary I get the right output. What am I doing wong?

Answer 1

1000001₁₀ = F4241₁₆, and 41₁₆ = 65₁₀ = A _ASCII

1000010₁₀ = F424A₁₆, and 4A₁₆ = 74₁₀ = J _ASCII