Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!usc!bbn.com!drilex!dricejb
From: dricejb@drilex.UUCP (Craig Jackson drilex1)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: compuserve
Message-ID: <27853@drilex.UUCP>
Date: 24 May 91 19:56:38 GMT
References: <9105201208.AA22490@tuatara.uofs.edu> <543@pyrite.nj.pyramid.com> <10716@rls.UUCP>
Organization: DRI/McGraw-Hill, Lexington, MA
Lines: 50

In article <10716@rls.UUCP> randy@rls.UUCP (Randall L. Smith) writes:
>In article <543@pyrite.nj.pyramid.com>, bill@pyrite.nj.pyramid.com (Bill Pechter) writes:
>> In article <9105201208.AA22490@tuatara.uofs.edu> bill@TUATARA.UOFS.EDU (Bill Gunshannon) writes:
>>>
>>> Unless things have changed drastically since the last article I read about
>>> Compuserve, they are running PRIME Mini's.
>> 
>> Nah, they're running DEC KL10's which run a modified TOPS10.  The Source,
>> purchased by Compuserve, ran Prime minis.
>
>True and they're now converting to VMS.  I toured their data center last
>fall and they still had *ton's* of RP06's!! The antique KL10's and KL20's
>still humming along.  The Primes were sitting the corner running but not
>being used, as I was told.  Modifying TOPS seemed to be a costly venture
>in the long run.  Might have been more costly to be out of business
>though.  Anyway, I really don't know how central it was to the business. 
>Presumably, very.  They do all (almost) their own hw support even on the
>new Vaxen.  The biggest Vax they had (at the time) was a 6410. 
>Usenet: randy@rls.uucp

I know that this is somewhat afield of tcp-ip, but I had heard from a former
employee that Compuserve was working with a company that had rights
to manufacture new DEC-20s.

Modifying the operating system heavily was the only way to run a timesharing
company in the '70s.  The vendor systems, especially on large machines,
simply didn't have the security, billing, and communications options
required to run a commercial timesharing business.  Most of the big
timesharing outfits had a real wrench getting onto newer hardware
and more standard software sometime during the '80s.  By then, vendor
software was a little more up to the task, and running standard software
didn't mean too many compromises.

Compuserve became more specialized than most and so has stayed on the
modified stuff longer.  They also have managed to extend the life of
a timesharing business longer than most--many of their competitors
have already or are now leaving the timesharing business.

An example of the things which were nearly mandatory in the timesharing
business is task reconnection.  With the low quality phones and modems
available then, disconnections were frequent.  It was not economically
viable to simply send your task a SIGHUP (or equivalent).  Most timesharing
companies had some concept of reconnecting to a running task.  Somebody
from Bell Labs presented a framework for doing this under Unix about
two years ago; I think portions of it may have made it into SVR4.

-- 
Craig Jackson
dricejb@drilex.dri.mgh.com
{bbn,axiom,redsox,atexnet,ka3ovk}!drilex!{dricej,dricejb}