USES Dos,Crt;
VAR Lw: Char;

FUNCTION Checkdrive(Drive : Byte): Boolean;
 VAR Regs: Registers;
   Anz_Floppy,A_Or_B: Byte;

 BEGIN
   Anz_Floppy:=((Mem[$40:$10] And 192) Shr 6)+1;
   A_Or_B:=Mem[$50:$04];
   If ((Drive=1) And (Anz_Floppy=1) And (A_Or_B=00))
   Or ((Drive=0) And (Anz_Floppy=1) And (A_Or_B=01)) Then
   BEGIN
     Checkdrive:=False;
     Exit;
   END;
   Checkdrive:=Not(Disksize(Drive+1)=-1);
 END;

BEGIN
 REPEAT
   BEGIN
     Lw:=Readkey;
     Lw:=Upcase(Lw);
     If Not Checkdrive(Ord(Lw)-65) Then
     Writeln('Laufwerk ',Lw,' nicht vorhanden')
     Else Writeln('Laufwerk ',Lw,' vorhanden');
   END;
 UNTIL Lw=#13;
END.