Program ular-ularan dengan pascal 6

Program ini hanya bisa dijalankan dengan turbo pascal 6:

program SNAKE;
uses crt;
type

TWORM=record
     L:byte;
     W:array [1..46,1..2]of integer;
     EOG:boolean;
     D:INTEGER;
     end;
var
N:integer;
S:byte;
K:byte;
MW:TWORM;
C:char;
F:boolean;
I, J:integer;
SCREEN:array[1..25,1..80] of word absolute $B800:0000;

{This instruction will read your key}
function FUN_KEY (var C:char):boolean;
begin
  FUN_KEY:=FALSE;
  F:=FALSE;
   C:=Readkey;
  if C=#0 then begin
                  FUN_KEY:=true;
                  F:=TRUE;
                  C:=readkey;
                  end;
end;

procedure INIT;
var
X,Y:integer;
I:integer;
begin
for I:=1 to 23 do
   for J:=1 to 73 do
    SCREEN[I,J]:=15*256+219;
    for I:=1 to 25 do
    for J:=74 to 80 do
    SCREEN[I,J]:=0;
   for I:=24 to 25 do
   for J:=1 to 80 do
   SCREEN[I,J]:=0;
    end;

{****************************************************************
{******************************************************************}
procedure SETSEED(S:byte);
var
X,Y:byte;
begin
 randomize;
 X:=random(23)+1;
 Y:=random(73)+1;
 while SCREEN[X,Y]<>15*256+219 do
 begin
   X:=random(23)+1;
   Y:=random(73)+1;
 end;
 SCREEN[X,Y]:=4*256+(48+S);
end;

procedure NGAME;
begin
randomize;
 INIT;
 MW.L:=1;
 MW.W[1,1]:=22;
 MW.W[1,2]:=40;
 K:=0;
 S:=1;
 MW.D:=1;
 SETSEED(S);
 N:=N div 2;
end;

{*******************************************************************}
procedure MOVE;
begin
  SCREEN[MW.W[MW.L,1],MW.W[MW.L,2]]:=15*256+219;
  if K>0 then
  begin
     MW.L:=MW.L+1;
     dec(K);
     end;

  for J:=MW.L downto 2 do
  begin
  MW.W[J,1]:=MW.W[J-1,1];
  MW.W[J,2]:=MW.W[J-1,2];
   SCREEN[MW.W[J,1],MW.W[J,2]]:=11*256+7;
  end;

  if MW.D= 1 then begin
                     if MW.W[1,1]=1 then MW.W[1,1]:=24;
                     MW.W[1,1]:=MW.W[1,1]-1;
                     end
  else if MW.D= 2 then begin
                     if MW.W[1,1]=23 then MW.W[1,1]:=0;
                     MW.W[1,1]:=MW.W[1,1]+1;
                     end
  else if MW.D= 3 then begin
                     if MW.W[1,2]=73 then MW.W[1,2]:=0;
                     MW.W[1,2]:=MW.W[1,2]+1;
                     end
  else  if MW.D= 4 then begin
                     if MW.W[1,2]=1 then MW.W[1,2]:=74;
                     MW.W[1,2]:=MW.W[1,2]-1;
                     end;
  if SCREEN[MW.W[1,1],MW.W[1,2]]=11*256+7 then
  begin
  gotoxy(1,24);
  textcolor(green);
  write('Game Over...');
  delay(100);
  MW.EOG:=false;
  end;
  if SCREEN[MW.W[1,1],MW.W[1,2]]=4*256+(48+S) then
  begin
  MW.L:=MW.L+1;
  K:=S-1+K;
  inc(S);
  MW.W[MW.L,1]:=MW.W[MW.L-1,1];
  MW.W[MW.L,2]:=MW.W[MW.L-1,2];
  if S=10 then NGAME
  else SETSEED(S);
  end
  else SCREEN[MW.W[1,1],MW.W[1,2]]:=3*256+42;
end;

{****************************************************************}
procedure EVENT(C:char;F:boolean);
begin
  if F and (C=#72) then
  if MW.D<>2 then MW.D:=1;
  if F and (C=#80) then
  if MW.D<>1 then MW.D:=2;
  if F and (C=#77) then
  if MW.D<>4 then MW.D:=3;
  if F and (C=#75) then
  if MW.D<>3 then MW.D:=4;
end;

{***************************************************************}
begin
 Randomize;
 INIT;

 FOR I:=2 to 46 do
 begin
 MW.W[I,1]:=1;
 MW.W[I,2]:=1;
 end;

 MW.L:=1;
 MW.W[1,1]:=22;
 MW.W[1,2]:=40;
 MW.D:=1;
 MW.EOG:=true;
 S:=1;
 SETSEED(S);
 N:=60;

 while (MW.EOG and not((not F) and (C=#27))) do
 begin
   MOVE;
   if keypressed then F:=FUN_KEY(C);
      EVENT(C,F);
      mem[$40:$1C]:=mem[$40:$1A];
      delay(N);
 end;
end.