[MrDiG]

Код:

const alf ='ABC';
var n1, n2,n3:integer;
  rs: string[3];
  list: TStringList;

list:=TstringList.Create;
for n1:=1 to length(alf)
begin
 rs[1]:=alf[n1];
 for n2:=1 to length(alf)
 begin 
  rs[2]:=alf[n2];
  for n3:=1 to length(alf)
  begin
    rs[3]:=alf[n3];
    list.add(rs);
  end;
end;
end;
list.savetofile(....);