TEK UNIX history

Later, Tek developed a microprocessor development system that utilized an LSI-11 core. It was called the 8250. -- 8550 and 8560 It was an evolultion of the systems that started with the 8002 8550s have an 11/02 in them and ran an OS called DOS-50, which I would REALLY like to find. The 8560s are UTEK machines starting with 11/23s and 8" drives and evolving through 11/73s and 5" drives. I have an 8560 with an 8" drive and would like to find the service manual for it (I have the svc docs for the 5" version). There is a fair amt of scanned documentation on the 8002->8560 up now on bitsavers. And dovetailing into Hans' comments, it is VERY difficult to find the documentation and software for these systems, while the hardware shows up at hamfests and on eBay frequently.