I think all of those machines ran an ATA/IDE 5.25" HD
You can use "Drive Setup" from Apple to format the HD - it's free and can be found at versiontracker.com
edit: Drive Setup is for pre OSX systems! I'm not sure how to format a OS X drive as I've never done it, but I'll dig around.
This should help for X:
http://www.kenstone.net/fcp_homepage/partitioning_tiger.html
I hope this helps!
Best,
Kurt