Miscellany

segment .data
    source db 'Best of times to learn is Now',0x0A, 0x0A
    sm db '',0x0A, 0x0A
    target db '',0x0A, 0x0A
    tm db '',0x0A, 0x0A
    len equ $ - source

segment .text
    global _start

_start:
    mov eax, 4
    mov ebx, 0
    mov ecx, source
    mov edx, len
    int 0x80

    mov ecx, len
    mov esi, 0

space_loop:
    mov al, [source+esi]
    mov bl, ' '
    cmp al, bl
    je end_loop
    mov [sm+esi], al
   
end_loop:
    inc esi
    loop space_loop

print:
    mov eax,4
    mov ebx,1
    mov ecx,sm
    mov edx,len
    int 0x80

exit:
    mov eax, 1
    mov ebx, 0
    int 0x80