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From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: net.arch,net.micro.16k,net.micro.68k
Subject: Re: 24 bit vs. 32 bit address space
Message-ID: <5522@utzoo.UUCP>
Date: Mon, 22-Apr-85 12:14:16 EST
Article-I.D.: utzoo.5522
Posted: Mon Apr 22 12:14:16 1985
Date-Received: Mon, 22-Apr-85 12:14:16 EST
References: <983@watdcsu.UUCP> <2385@nsc.UUCP> <730@amdcad.UUCP> <523@inset.UUCP> <5351@utzoo.UUCP>
Organization: U of Toronto Zoology
Lines: 14

> Mr. Spencer asks "Incidentally, how do you implement a pipe or a terminal as
> a segment?"  Well, I'm just a dumb application programmer but our O.S., running
> on the iAPX286, implements real, honest-to-goodness Unix pipes and devices.

Of course.  But if I'm not mistaken, they are not implemented as segments
in the address space of processes.  Which is what the original discussion
was about.  You can implement Unix pipes and devices on most anything;
whether the machine is segmented or not makes no difference.  The point
is, you can map files into a process's address space on a sufficiently-
cooperative machine (I doubt that the 80*86 qualifies), but it is very
hard to make pipes and devices act like files if you do this.
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry