Hi,
I have never had good success installing the OS, particularly on the D8B, when I follow Mackie's "conditioning" recommendations. Try installing a "raw" hard disk. You can use usb to ide connector to use a disk management program to completely wipe and delete "all" partitions from the disk. Something else I learned the hard way is that many of the floppy drives installed in these machines will cease to be capable of loading the OS even though they appear functional. I currently have only 1 HDR that has a good floppy drive and I have to use it to load the D8b OS onto a hard drive and then transfer that drive into my D8B. Good luck. One other thing sometimes it takes an "aggressive" re-seat of the video card to get that part of the puzzle to work. Again, may God smile on your efforts.
Have a Blessed Day,
Mike W.