Устранить в коде ошибку деления на ноль - Turbo Pascal

{$X+}
Uses    Graph, Crt;
Type    TMassiv = Array[1..89] of Real;
    FileofMassiv = File of TMassiv;
Var
    Max, Min : Real;
        k : Longint; FF : TMassiv;
        f2:Text; f1 : FileofMassiv;  s2 : String[2];
Procedure PrintZaryad(FF : TMassiv; yMax, yMin : Real; s:String);
var
    b,a,x,zerox,zeroy,gd,gm,xmin,xmax,x2,y2 : integer;
    kx,ky,y : Real;
Begin
 gd:=0; InitGraph(gd,gm,'');  If GraphResult <> 0 then halt;
 a:=1;    b:=89;
      if ymin>0 then ymin:=0;      if ymax<0 then ymax:=0;
 xmin:=a; xmax:=b;
      if xmin>0 then xmin:=0;      if xmax<0 then xmax:=0;
 kx:=(Getmaxx-10-10)/(xmax-xmin);      ky:=(Getmaxy-10-10)/(ymax-ymin);
      Zerox:=Round(kx*(-xmin))+10;
      Zeroy:=GETMAXY-(Round(ky*(-ymin))+10);
 SetLineStyle(0,0,1);      SetbkColor(0);      SetColor(14);
      Line(10,Zeroy, Getmaxx-10,Zeroy);
      Line(Zerox,10, Zerox,GetmaxY-10);
 x:=a;                     SetColor(12);
 
Moveto(Round(kx*x)+Zerox,Zeroy-(Round(ky*FF[x])));
      Repeat
        x:=x+1;
Lineto(Round(kx*x)+Zerox,Zeroy-(Round(ky*FF[x])));
      Until x>=b;
 x2:=10;                  SetColor(10);
    Repeat
      Line(x2,Zeroy-5,x2,Zeroy+5);
        x2:=x2+10;
    Until x2>(GetmaxX-10);
 y2:=10;
    Repeat
      Line(Zerox-5,y2,Zerox+5,y2);
        y2:=y2+10;
    Until y2>(GetmaxY-10);
    OutTextXY(50, 250, 'A = '+s);
  Readln;
 CloseGraph;
End;
 
Begin       {********* PrograM MAIN **********}
 
    Assign(f2,'c:\zar\MaxMin'); Reset(f2);
    Readln(f2,Max);         Readln(f2,Min);
                Close(f2);
   For k:=1 to 89 do Begin
     str(k,s2);
       Assign(f1,'c:\zar\'+'1'+s2); Reset(f1);
        Read(f1,FF);
        PrintZaryad(FF, Max, Min, s2);
     Close(f1);
    End;
End.