//  reverse_in_stack.iml  (c) 1997 - 2000 Kari Laitinen

//  The following program is similar to "reverse_in_memory.iml".
//  It reads a text from keyboard as a string of ASCII characters.
//  After receiving a space, it displays the characters
//  in reverse order. This program puts the characters into the
//  stack. In the end it reads the characters away from the stack.
//  Due to the nature of stack as a data storage, the characters
//  will automatically come out in reverse order.

beginning_of_program:
      load_register_a_with_value       0
      push_register_a_to_stack

read_character:
      call_subroutine                  read_and_echo_a_character
      push_register_a_to_stack
      load_register_b_with_value       ' '  //  code for space
      jump_if_registers_equal          print_characters_from_stack
      jump_to_address                  read_character

print_characters_from_stack:
      pop_register_a_from_stack
      jump_if_register_a_zero          all_characters_printed
      output_byte_from_register_a
      jump_to_address                  print_characters_from_stack

all_characters_printed:
      stop_processing


read_and_echo_a_character:
      jump_if_input_not_ready          read_and_echo_a_character
      input_byte_to_register_a
      output_byte_from_register_a
      return_to_calling_program