if you look at the motherboard it will perhaps have these marked as ide1 and ide2 connect the ide 1 cable to your hard drive and ide 2 to the cd drives bear in mind the cd drives will have a small jumper in the back and one will need to be set as master and the other as slave,as far as the floppy drive goes it is a different sized connector and you cannot get the wrong one but you can in some cases get it upside down.