Alas no documentation I have on those NCR towers, or much could add (though very robust kit as never had any issue with them hardware wise and even in a warehouse/distribution hub and decommissioning one with over an inch diesel soot caked inside and thinking I need hazard pay). Alas lost a lot of my manuals in a move, along with old systems couple decades ago. All I have left are some IBM stuff, well duplicated across the net, IBM good with there online documentation. Just wished had the ICL and Honeywell mainframe manuals I had still.
There's very little on the internet about those "NCR Towers."
> 1987: https://www.techmonitor.ai/hardware/ncr_marries_its_tower_un...: "Despite abandoning its effort to implement Unix on its NCR 32 chip set, NCR Corp did not abandon its ambition to bring Unix into the mainstream of its mainframe product offerings, and the company yesterday launched a facility whereby its top-end multiprocessor Series 9800 fault-tolerant mainframes can be used as servers to a network of 68020-based Tower Unix supermicros."
> 1988: https://www.techmonitor.ai/hardware/ncr_renews_its_tower_uni...: "When you sell as many machines as NCR does with the Tower, you can’t rush to incorporate a new chip as soon as it arrives because there simply aren’t enough chips to meet your needs. Accordingly the new Tower models use the 25MHz 68020 rather than the 68030."