SAFE CRACK

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by Stephen Parry

from ZX Computing, June/July 1984



Answer the questions and break into Stephen Parry's Southampton safe.





This is not just another code-breaking game but a simple maths program for

use in primary schools involving addition, subtraction and multiplication.

There are fifteen boxes, each occupied by a red question mark (?) and every

correct answer replaces the question mark with a blue pound sign (). The

object is of course to fill all the boxes with pound signs  if anything will

attract and occupy the minds of children, it's money! Every wrong answer

loses a pound sign but the computer will keep on asking questions until

someone wins. Filling all the squares with pound signs will give a large

fanfare of sound and a colourful screen display.



The program runs by first calling the subroutine at 8900. This draws a

colourful screen with accompanying sound and a sum is randomly devised in

lines 7000 to 7050. To do this, line 7020 chooses whether addition,

subtraction or multiplication is to be performed and line 7030 makes sure

that if multiplication is chosen then the numbers are kept within the range

of 1 to 12. Line 7040 chooses two numbers and the value 100 can easily be

changed if smaller numbers are wanted. Line 7050 ensures that no negative

numbers result from subtraction and then line 7060 builds the sum itself.



After answering the question from a series of screen prompts. the child is

immediately told the answer which is worked out in line 7120. Having compared

the childs answer with that of the computer, the program either jumps to a

fail message which replaces the pound sign with a question mark or to line

7700, which places a pound sign in the next box. If the variable tot reaches

15, meaning that all the boxes have been filled, the subroutine at line 8000

is called which displays a win message and the usual "do you want another go"

question is asked.

