I am unsure of how to actually store user-input data to a register. I would like to prompt the user for a signed base-10 integer, then store that integer to the bx register. What I have does not seem to be actually storing any data from what I can tell:
Code:
;get user input

   mov   ah, 0Ah
   int   21h


while:
    mov   bx, ax        ;save char to bx
    cmp   ax, 13        ;is
...