
D-116, an obscure clone of an overlooked mini computer [video] - fortran77
https://www.youtube.com/watch?v=tbxW85Cj6y8
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vajrabum
If the DG Nova, which is the overlooked mini in the title, is overlooked, it's
only because the people doing the looking weren't around when they were
popular. By the standards of the day Data General made a lot of them. See here
for a few more tidbits: [http://ed-thelen.org/comp-hist/dg-
nova.html](http://ed-thelen.org/comp-hist/dg-nova.html)

~~~
tyingq
Says 60,000 sold. That's not bad at all, considering the PDP-11 sold 20,000 in
its first six years[1]. The PDP-11 did sell 600k total, but that would be over
a lot of models over a very long period of time.

[1] [https://dave.cheney.net/2017/12/04/what-have-we-learned-
from...](https://dave.cheney.net/2017/12/04/what-have-we-learned-from-the-
pdp-11)

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wrs
Fun to see this! I was an operator in our high school computer lab, which had
a Nova 2 with a similar boot process (except we had a 9-track tape drive and
10MB Winchester to load binaries from...that paper tape is brutal). I had it
memorized and could just about do it at “8x speed”. :) We ran multiuser stand-
alone BASIC with four ASR33s in a room that must have violated noise-safety
standards.

This multistage process is still how pretty much everything boots, BTW, except
you start with a ROM rather than a human flipping switches. Back in those days
a boot ROM was an expensive option you could do without.

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drallison
The DG Nova in its day was a workhorse mini-computer. I worked with Bob
McClure (Unidot) and built an "optimizing" C compiler that had surprisingly
good performance. We ended up re-organizing the code generated so we could
take advantage of the short offset and indirect addressing of the machine
without adding extra instructions. Likewise, we used an unusual approach to
managing stack frame addressing which was well suited to the DG Nova
addressing.

The DG Nova hadware was simple largely because it was built in TTL and the ALU
was a 74181. In the mid-1960's the final project in the logic design course
was to design a DG Nova machine using TTL.

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tyingq
It's an Entrex D116, which is a clone of a Data General Nova 1200[1] if you
don't want to watch the video.

There's an archive with some pictures from an eBay listing here:
[https://entrex480.blogspot.com/2017/05/entrex-480.html?m=1](https://entrex480.blogspot.com/2017/05/entrex-480.html?m=1)

[1]
[https://en.m.wikipedia.org/wiki/Data_General_Nova](https://en.m.wikipedia.org/wiki/Data_General_Nova)

~~~
valuearb
The Wikipedia entry is a fascinating read. It reminds me of how hard it was to
get to where we are today, the myriad of small incremental innovations
necessary to advance from each generation.

I need to read Soul of a New Machine again.

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cafard
I worked many years ago for a company that sold typesetting systems using DG
Novas and Eclipses (16 and 32-bit both). As I recall, the RDOS CLI and system
call manual was a wire-bound paperback that would fit into a reasonably sized
back pocket. The AOS/VS system call manual needed a fairly large three-ring
binder, and the AOS/VS CLI and utility manual came as a small one.

------
drallison
DCC and DG clashed over the cloning of the DG machine. See
[https://en.wikipedia.org/wiki/Data_General_Corp._v._Digital_...](https://en.wikipedia.org/wiki/Data_General_Corp._v._Digital_Computer_Controls,_Inc).

