The NCR DMV has lots of little options modules that plug into the mainboard at the back of the machine. Together with the internal slot, this is one heck of a machine.
I've taken pictures of the mainboard and the modules I have, for most of them I also have the technical documentation: Pictures NCR DMV
They keyboard is non-standard again, warm start is via Ctrl-F20.
The internal 8086 (or rather V20) module is special, as it allows the 68k module to be added externally. This allows a wide range of OS: CP/M-80, CP/M-86, DOS, CP/M-68k and USCD-Pascal are the ones I know of.
I've dumped the ROM of the 8086 module with my old eprommer: NCR DMV 8086 option ROM
The hard disk is in an external enclosure that is connected via an option module that in turn connects to a SASI=>MFM controller, as you can see in the pictures.