Toys - on the shelves: Bulls and Cows

ZX Format #01
(C) P. Rindin


         Bulls and cows.


      (See Appendix)


   This simple game is as old as
world. Still, I remember, in times of
Tower of Babel, when God
not intend to create exciting
diversity every BASIC
and Pascal, played it. And now, like as not going to forget. 
What is special about it? It is not clear.


   It begins, as always, with
saver. As always, click
ENTER or SPACE leads to its
(Background) disappearance. Then
You are invited to choose the level of
games - from zero to the Ninth
(In ascending order of difficulty). AND
only then the game itself.

   The computer thinks of a certain
four-digit number, which
No similar figures. For example
5702. You type something like this (four-digit, with different
figures). Let it be 1234.
In response, the machine will return
Post 1 / 0. This means that
You guessed one number (2), but
positioned it is not there. Assume that for the second time you 
enter number 5678. Now the answer to your computer will be 2 / 
1. Two digits guessed, and one of them is the right place. 
Progress. 

   Thus is very clear
goal of the game - guess the number of
minimal time and number of
moves.

   If you suddenly lost,
then press ENTER or SPACE -
at least look at this pernicious number.