I have never installed sco before and have inherited a server that needs replacing. I have a ml310 g5 with a SC44Ge adaptor for the hard disk and an SC11Xe for the tape drive. My problem is that the If I load sco507 with both cards in it cannot find a root HD controller. If I remove the tape card then it finds the disk and will load.Howver if I then install the tape card I get the no root controller error again. Both card use the lsil BTLD driver.

I hope for you a mod will move this post to a more suitable group (SCO?) Since I dont see anything "for dummies" here...
And I truly wish someone can help you out (I turned of my last SCO 5 years ago, and dont remember a thing... only that it was tricky...)

And I would not advise you to try to post there since the rules are:
" (4) Do not 'bump up' questions if they are not answered promptly. No duplicate or cross-posting and do not report a post or send a private message where your goal is to get an answer more quickly. "

All the best

Based on my personal forecast of SCO's business development I would install that system into a VM if I were on your shoes. You could emulate very common hardware to the guest OS and make installation and other hardware-related tasks as easy as possible. (which by the way does presumably save money: the full quad core would be a waste of ressources (or did the descendant system have similiar specs?)).

At the point at which it asks you whether you wish to install any optional drivers you should insert your HBA CD. There are only a limited set of drivers on the CD, and certainly on osr6 the drivers for the controller in my G5 weren't there. You will need to find these and make a disk from them.