If you want an internal install then a sata controller maybe needed but if this computer don't have sata connections.
I have an old edi computer with a small HDD and thought I might add my SATA HDD from a pc that no longer works to it as a second drive. I have some converter cables etc for power and piggy backing the new drive from the old one, but not sure how exactly to do it nor if it will work. Is there anything I need to do so I won't accidently wreck either the HDD or the pc? Cheers