Missing cards?
They just might be empty, unused slots in the
backplane.
That sounds like you've got the basic compliment. As I recall from my
days
running a network of them, the base DN10K has four cards (Network,
video,
CPU and memory). Extra slots were available for an FPU, more memory
(and
maybe a disk controller?). The CPU should be easy to identify by the
presence of a MC68010 chip.
The DN10K's typically did not have their own disk drives; instead they
booted (and paged!) off of a "partner" server node having the disk.
The
network adapters (in a plastic box that screwed onto the back) were
spectacularly flaky on those machines.
Apollo DN10k machines were the PRISM (A88k) architecture and would have
a multichip (LSI) CPU on the XBus that includes a FPA. The DN10k was a
SMP-capable machine, so it is likely that (unless yours is SMP) there
will be some extra XBus slots.
DN300 was another Apollo oddity- bitslice CPU that (if I was informed
correctly) emulates a 68030, and was done to "fill the gap" until
Motorola had shipping parts.