defword get_hex
    f and
    dup 9 > if
        a - 'a' +
    else
        '0' +
    fi
exit

defword print_hex
    dup 1c shr get_hex sys_write
    dup 18 shr get_hex sys_write
    dup 14 shr get_hex sys_write
    dup 10 shr get_hex sys_write
    dup c shr get_hex sys_write
    dup 8 shr get_hex sys_write
    dup 4 shr get_hex sys_write
    get_hex sys_write
    a sys_write
exit

defword print_stack
    dup
    do
    dup 0 = until
        over over - 2 + get print_hex
        1 -
    od
    drop
exit