My interest in the Rainbow gained new life when I was contacted by Warner L. about the original VENIX distribution disks I reported getting from the U of Delaware here, which apparently are very hard to track down. VENIX is the UNIX derivative for DEC Rainbow created by Tarik Isani. At the time Warner originally contacted I had no working Rainbow to use to copy the disks nor did I have a quad-density drive in my disk imaging system to copy them. So, I sent him the disks so he could image them, and I also scanned the installation instructions from the manual. Yes I need to copy the entire thing at some point, 6 binders.
About the same time I picked up a third Rainbow system that I could use for parts. This one had a working motherboard but no monitor. It was finally time for me to put the three systems together into one running Rainbow. What you read above is all of the results.
Warner got VENIX up and running on his Rainbow. Good, the disks work. I found another copy of the disks (minus the 1st/XFER disk) so I did not have to use the originals.
More about VENIX:
In anticipation of receiving the returned disks I partitioned the hard drive to hold VENIX plus a small MS DOS partition for utility purposes. Stand by...Warner suggest I use the files he uploaded to his site, or at least get his copy of the XFER disk by using rbimg (iwrite) utility. Not sure yet how that works.