DCC-116 E / DATA GENERAL NOVA 2/10 / Nixdorf 620 - Restoring and restarting

[Christian Kennedy]

> On 4/4/2017 7:09 AM, Dominique Carlier via cctalk wrote:

>> Concerning the memory, I analyzed more in detail, I think finally that
>> all the memory is core type, 1 X 16KW (it is marked on it) and 2 X 8KW
>> (according to the size of the core package in comparison with the 16KW
>> board). Thus a total of 32KW.

Yes, that would be a reasonable maximum configuration for this machine.

I yanked the CPU board out of my DCC 116 literally for the
first time, ever, which sent me down a rabbit hole.

Yes, it's a 1200 clone, which surprised me -- but the 1980 date on
the etch of your CPU is quite interesting.  Turns out DCC literally
stole the prints for the 1200 and used it as the basis of the D-116 (the
also apparently ripped off the PDP-8 and PDP-11).  At least in the case
of the D-116 it was literally a case of building to DG's prints, so much
so that the judge in the infringement case told DCC that had they
actually reverse engineered the 1200 they would have prevailed, but that
it was so obvious that they'd just done a punch of the machine that they
had to hand the injunction to DG.

Where this gets interesting is the timing.  DG won the injunction in
September 1975, and it so crippled DCC that DG ended up acquiring DCC
and their product line in 1977 and eventually putting a stake in the
heart of the product line at the end of the 70s.

Does your CPU board have a DCC or DG copyright on it?

Making it stranger is the prohibition on putting anything in slot two
(mine has the same restriction).  I'd have to look closely, but that
suggests that while the design ripped off the 1200 CPU it ripped off the
800 backplane (the 800 CPU takes two slots, the 1200 only one, and
thanks to the way the backplane is wired it's possible to run a 1200 CPU
in an 800 chassis).

Finding a basic I/O board shouldn't be difficult; you only need TTY (not
reader or punch controls), and while it would be nice you probably don't
need the RTC, either.  Still, given the date of your machine the TTY
functionality /may/ be on the CPU card itself.

Is there a DB-9 connector somewhere on the rear bulkhead of the machine?

-- 
Christian Kennedy, Ph.D.
chris at mainecoon.com	AF6AP | DB00000692 | PG00029419
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"Mr. McKittrick, after careful consideration…"