The front mass storage device slots on the Compaq AlphaStation XP1000 System accomodate 3.5-inch drives with the addition of expansion brackets. If you are replacing a 3.5-inch device, you will need to remove the side rail from the expansion brackets, then remove the brackets themselves.

To install the replacement 3.5-inch drive, first install the expansion brackets then the side rail on the replacement drive, and return to the front accessible drive replacement procedures," step 5.