Seeing this is a normal A2000 drive be sure to look if the drive is jumpered as df0: or df1:. If the drive appears to be dud check to see if the jumper D0 is set instead of D1.
Should work flawless with a 1200. If yours is a late Amiga Technologies model you will need to hack it a little.
Also, if putting it in a Power Tower it will take up 2 3.5" bays, these drives are 1.6" high instead of 1" of most PC floppy drives.