ZX Computings - OpenLibra

After taking your move the
computer will react "My
move" followed by "Search".
The search routine then checks
all 195 possible moves to see if
it can claim any squares. If it
can, it will complete the square
and start again with "My
move". Unfortunately the
search takes approximately 1 2
seconds. This routine may be
altered to a FAST mode by inserting
a new line 153 FAST
followed by a new line at 167
SLOW.
This means that the screen
will blank out for a couple of
seconds during the search,
which in my opinion is not so
good. If the search is unsuccessful
the word "Search" is
followed by an "X" after which
it makes its choice of move.
This is reasonably fast and normally
takes only a second or
two depending on the complexity
of the situation. It does this
by the simple reasoning: if one
of its choices is impractical then
it will not take that move into
account again.
When the grid becomes so
full that it is impossible to move
without giving any squares
away, the program is not able to
take into account how many
squares you can claim from its
move. For this reason the computer
scores two points for
every square it takes.
The ultimate object being
not only to win, but to beat the
computer 88 to 0, which is
almost impossible. If, however,
you beat it by 50 points (which
is very difficult), the coveted
"Congratulations" line prints
up.
The BREAK key will stop the
program at any time. (This can
be useful for sampling the patterns
by simply: BREAK, RUN,
another choice of pattern
number.) Working out where
the computer is going to move
next has been deliberately
made difficult to follow after its
first couple of moves.
The Program
Lines 2-10 set up the instructions.
Note:- Double words, (eg
fora) are separated by the end
of one line and the beginning of
the next.
Line 12 goes to an inkey $ trap.
(Sub 400.) The program will
not continue until a key is pressed.
The value of the key is
recorded in Z $. Not used in this
case.
Lines 16-26 set up the
variables. A:- Keeps a record of
the 195 possible moves.
V:-Records the score. C:-
Defines "whose move". F:-
Starts the computer's turn
position. G:-lndicates if there
are any safe moves left. I:-Is used
to search/ modify the data in
A.
Lines 28-52 set up the display
grid etc.
Lines 54-60 set up D which is
used for the pattern routine.
Lines 62-64 set up "My
score", "Your score". These
look better in inverse characters.
Sub 420 simply blanksout
the line at 1 9, 0; and sets the
next print position again for this
line.
Lines 66-72 sort out whose
move. (The pattern starts at
220. The "My move" starts
at 1 50.)
Lines 74-100 set up all the
variables and traps for "Your
moves" choice. X - Value for
the position acrots the grid.
This can be from 0 to 11. (0 for
A, 1 for B and C, 2 for D and E
etc.) This, together with information
of whether an odd or
even line number down, sorts
out the print position. This arrangement
prevents illegal entries
on the dots or in the middle
of the squares. Y = the up/
down position.
Line 102 goes to the last line of
Sub 470 to get the odd or even
number which is stored in E.
E=0 for even, 1 for odd.
Lines 104-106 again prevents
illegal entries and prevents
entering a move already taken.
Lines 108-110 store and print
a move.
Line 112 Q = The number of
sides to be taken into account in
Sub 440. Sub 430 simply zeros
J, K, L and M in Sub 440 these
variables change to 1 if anytjf
the four directions possible
from a position has Q number of
16K Programs.
sides altogether (eg in this case
Q = 4 thus any four sides in any
four directions will let J, K, L or
M at least equal 1).
Lines 118-126 If the four sides
of a square are present, then
the program will go to various
parts of subroutine 480. This
routine works out by J, K, L or
M, the direction of the print
statement, which will 'black'
the squares and insert an "*" a
" -" or a "/" depending upon
whose move claimed the
square.
This simply takes the value
of whose turn (in C) adds 22
and prints the CHR $. U is simply
used to help simplify the print
statements.
Line 128 If there is no pattern or
winning move then let C = ABS
(C-1). This changes the
player's turns. If C=1 it
becomes Q and vice versa.
Lines 130-134 sort out the
score. If all 88 squares are
taken then the game finishes at
line 144 where pressing any
key starts another game.
Otherwise line 1 36 starts the
next turn by jumping back to
line 64.
Lines 150-166 Starts the
search routine during "My
turn" using part of Sub 440,
only this time Q = 3. If L or
M = 1 then its found a threesided
square. In this case line
200-210 loop around until the
missing side position is found.
Since "My turn" looks directly
at a position (I) and doesn't
choose X, Y co-ordinates then
sub routine 470 supplies X, Y,
and E. it then jumps back into
the original program at Line
106 having worked out its
move.
Lines 168-196 constitute the
computer's turn if the search
for three sides is unsuccessful.
This will choose any untaken
position other than one which
will make up more than two
sides in any square. (Q = 2 this
time.) It starts at position two
(I) and jumps in steps of 60, to
find a suitable position. If
l> 1 95 then let 1-1-193
keeps this within the "A"
boundary. This tests each
number from 2 to 195 without
repeating, looking reasonably
at random.
Once 1 95 is reached G = 1
and Q = 4 allowing the next
available position to be taken.
This time at line 196 we return
to the main program 104, to
allow a little longer to display
the "My moves" choice (line
194). (X * 2 + 37 + E) works
out the relevant letter.
Note: If you wish to set up
the pattern fast then insert Line
221 FAST and line 69 SLOW.
2 CLS
4 PRINT "SQUAREOLOGY",„"BY J. ENNESS"
6 PRINT AT 3,3;"THE OBJECT OF THIS GAME IS TOJOIN
THE DOTS AND COMPLETE AS","MANY SQUARES AS
POSSIBLE. THE"," COMPUTER ALSO TRYS THIS: AFTER
"," MAKING THE FOURTH MOVE ON ANY'V'THIRD
SIDE."
8 PRINT " [ ] ( ] [ ] THE COMPLETION OF A SQUARE
"/'WILL BLACKEN THE GREY LINES AND","PUT AN
.»OR""-"" IN ITS CENTRE"," NOTE:-THE
COMPUTER SCORES TWO'Y'POINTS PER SQUARE YOU
LOSE."
10 PRINT "[ ] [ l t ] TO START SELECT A PATTERN
1-90R " "0" " FOR NO PATTERN OR A-Z FORA
MYSTERY START. TO ENTER A MOVEPRESS THE
LETTER THEN NUMBER/S'V'OF THE REQUIRED
POSITION. THE","WINNER OF A SQUARE HAS A
SECOND MOVE.",," [ ] [ 1 [ ] ( ] PRESS ANY KEY
TO START"
12 GOSUB 400
14 CLS
ZX COMPUTING SUMMER 1982 125