Cracker  -  A code breaking puzzle

by Richard Taylor

Cracker, as its name suggests, is a puzzle where the hidden code must be
cracked. The computer generates a code which is a sequence of four
colours, say blue-grey-green-black. The object is to break it with the aid
of marks you are given after each successive guess.

The program can be run from the RISC User menu system, or by double-clicking on its icon in a directory viewer. An icon is installed on the icon bar. Click on this icon and a
window will be opened. The four grey squares at the top left hide the
four colour code chosen by the computer. Now you must fill in the first row
of light grey squares towards the bottom of the window - the row which has a little green square
icon beside it as opposed to a red one - with your first guess. To do this, first click on one of the six colours at the bottom of the window to select it, then click on one of the grey squares in the row to be filled. The selected colour will now be placed in that square.

When you have filled in the squares with the four colours that you wish to
use for your first (uninformed) guess, click on the OK icon to the far
right of the row. The four adjacent small icons which are arranged in a
square should then change colour in order to indicate how close your guess
is. One of these little 'marking' squares is changed to light blue (cyan)
for every one of your colours that is in the code and in the right position
as well. For each colour that is in the code, but in the wrong place, a
marking square is changed to yellow. The rest of the marking squares, if
any, are changed to mid grey. You can now take a (slightly more educated)
guess by filling in the second row of light grey squares, which now also has
a small green icon next to it.

Simply carry on like this, using the information from all the previous rows
to infer as much as possible about the code. You should normally ensure
that your guess is consistent with the marks given to all the previous rows.
If you manage to crack the code, all four of the marking squares on the
current row will change to light blue as you would expect, and the code will
also be revealed at the top of the screen. Note that you only have ten
attempts to break the code, after which it will be revealed anyway. You
may give up before this by clicking on the Reveal icon at the top of the
window. This icon is beneath the timer which tells you how long it
took you to crack the code, or to give up! Once the code has been
revealed, clicking on Restart will begin the puzzle all over again with a
new code in place.

If you're beginning to find the puzzle too easy or too hard then you may
wish to increase or decrease the number of available colours the computer
can choose from to make up the code. Bring up the application's icon bar
menu and choose the Choices... entry. This in turn brings up a dialogue
box allowing the number of available colours to be changed. It also
contains an option icon permitting the computer to use repeated colours in
its code, which obviously makes the puzzle harder. A good challenge is
given by allowing eight colours with repeats - the form in which I first saw
the game. Note that if there were two black squares in the code and you
placed one black square in your guess then only one marking square would be
coloured cyan or yellow. This would also happen if there were only one
black square in the code and you guessed at two.

Now click on OK and the number of coloured icons at the bottom of the main
window will be altered to reflect any changes. Clicking on Save will do
the same but will also ensure that the current values are used the next time the
application is run. Note that updating these values automatically
creates a new puzzle using the new conditions.

Copyright  RISC User 1995
