[TUHS] ISO, OSI, and DECnet (was Re: If not Linux, then what?)

Clem Cole clemc at ccc.com
Fri Aug 30 23:59:08 AEST 2019

Besides DECnet, IIRC, in the USA the only semi-large (required) use of OSI
was for TOP [Technical Office Protocol] and MAP [manufacturing automation
protocol]  that GM and Boeing tried to ram down the industries virtual
throat.   At Masscomp, we had already built an OSI/X.25 interface for
Europe, but since I ran Datacom and these folks were definitely my target
customers for a real-time system, I had to listen to them.  I spent way too
many hours in GM and Boeing conference rooms dealing with it.   By memory,
the arguments for MAP over ethernet was the later was considered
'unpredictable', they claimed they all had to have fiber on the
manufacturing floor, and were convinced that TCP/IP had 'too much overhead'
for real-time automation.  I never really understood the justification of
why TOP was needed, other than there were a bunch of folks in both places
running DECnet and there was a huge level of NIH.

When I was at Masscomp, I don't think we ever sold many systems into GM.
But our stop-gap for Ford was to use Protean fiber-based boards on the
manufacturing floor and continued to run TCP on top it, and our traditional
Ethernet was just fine by them, "thank you."  Since Ford Aerospace was our
partner for building the new Mission Control at NASA (we ran redundant
ethernet there), they were already pretty familiar with our Ethernet and IP
stack products, so they took over working with the folks inside of Ford.
Shortly thereafter, Masscomp and Apollo won the bid for the Boeing 7J7
program (which became the 777 when it shipped).  The agreed (common)
interface between all three firms was Ethernet and IP.  [**]

I left for Stellar, but I don't think they ever built either the MAP/TOP or
any of the rest of the OSI stuff besides X.25, funny how they stopped
asking for it.  I still have a binder of all the TOP specs in my basement.

[**] An interesting factoid that I thought of while writing this reply.
One thing I learned from working with Boeing during that time is that until
that program, the C5A and the 747-400 were the only two airplanes that
could carry their documentation as a payload.  The paper required for the
FAA weighed that much.  One of the justifications of the 7J7 was they had
gotten approval from the FAA to make all of the documentation delivered
electronically.  It was the first plane they designed 100% using CAD and no
paper or other models.  Masscomp systems on the manufacturing floor, and
Apollo's in the engineering offices.
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