I removed my 40 GB HD from my Quicksilver 733 a long time ago and tried to install it in my old Performa 6300. I was entirely ignorant of the fact that older Macs could not boot from large HDs. My Grape iMac had to have the boot partition around 7 GB to work. The Performa, I believe, can only work from around a 4 or 5. While fiddling with the hard drive, I tried every combination of jumper settings to try to get it to work. Of course, I didn't write the original configuration down and have no solid idea which one to use. The two likeliest ones are the fifteen head and sixteen head master settings. Could someone please tell me which jumper setting to use. I am going to install it in a Blueberry iMac to give to my nephew and I'd like to use it instead of letting it sit around and collect dust. Thanks Fred