Path: utzoo!mnetor!uunet!lll-winken!lll-tis!ames!pioneer!eugene
From: eugene@pioneer.arpa (Eugene N. Miya)
Newsgroups: comp.arch
Subject: Re: Universal OS (was Re: Survey of architectures)
Message-ID: <7850@ames.arpa>
Date: 25 Apr 88 20:30:05 GMT
References: <2048@gumby.mips.COM> <10504@steinmetz.ge.com> <7657@ames.arpa> <769@imagine.PAWL.RPI.EDU> <1520@pt.cs.cmu.edu>
Sender: usenet@ames.arpa
Reply-To: eugene@pioneer.UUCP (Eugene N. Miya)
Followup-To: comp.os.research
Organization: NASA Ames Research Center, Moffett Field, Calif.
Lines: 44

In article <1520@pt.cs.cmu.edu> edw@IUS1.CS.CMU.EDU (Eddie Wyatt) writes:
> >>First, I would question whether the original poster really cares. . .
> >>My claim is that most people are not directly
> >>exposed to these aspects of a computer system and that they
> >>could really care less.
> > 	Usually this is quite correct, most users only care if it runs the
> > software they want to use and how fast it does this.
>  Not really true.  When every you have heterogeneous enviroment, the
>user must be concerned.  The is a whole hierarchy of interfacing.

You make an excellent point here about hetergeneous systems, and this
is what the issue of `transparent systems' should be about.  Concern is
one thing, but getting work done is another.  I give you an example from
personal experience using your own model:

>	1. data representation - important when data is shared between
>		hosts (is there work needed in transforming the data?)

In 1973, I was learning to get around on the ARPAnet. I learned how to use
this command called "FTP" on our IBM 360/75 to get source files from
a distant machine, something called, a "DEC-10"  ;-).  The Fortran had
'#' for '='.  This was an anoyance.  Text editors were few at the time,
and the changes minor, but the point is I had to do the changes.  I should not
have to do even this minor of the changes: how, for instance would I know
that I got them all?  Especially if the program is big.

>	2. object code - sun-4 objects are not compatible with sun-3 and
>		hence two versions of the objects must be kept.
>	3. OS - what is the interface to the signal handler under
>		SYS V and BSD!

Good points.  More fundamental questions could be made about I/O.
I suggest Habermann's CACM paper on FAMOS (Families of Operating Systems)
and Amdahl's paper on the 360/370 architecture as compatibility lessons.
Note, I we are diverging from architectures and I have suggested follow-ups
to comp.os.research.

Another gross generalization from

--eugene miya, NASA Ames Research Center, eugene@ames-aurora.ARPA
				soon to be aurora.arc.nasa.gov
at the Rock of Ages Home for Retired Hackers:
  "Mailers?! HA!"
  {uunet,hplabs,hao,ihnp4,decwrl,allegra,tektronix}!ames!aurora!eugene
  "Send mail, avoid follow-ups.  If enough, I'll summarize."