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From: RCONN@simtel20.arpa
Newsgroups: comp.sys.misc
Subject: Re: What is an OS?
Message-ID: <3700@brl-adm.ARPA>
Date: Mon, 26-Jan-87 08:22:15 EST
Article-I.D.: brl-adm.3700
Posted: Mon Jan 26 08:22:15 1987
Date-Received: Tue, 27-Jan-87 02:16:35 EST
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A textbook definition of an Operating System is that of a "resource manager",
or, more specifically, a program which manages the resources of a computer
system.  What are the resources of a computer system?  There are
four basic resource:
	1) memory
	2) devices (including disks, tapes, channels [I/O processors], etc)
	3) processes and processors (a process is a running program)
	4) information (files, directories)

There are many kinds of operating systems (based on this definition), and
CP/M, RT11, RSX11, RSTS, VMS, UNIX, VM/CMS, ITS, TOPS-20, etc.  Some OSs
allow the application software to take control away from the OS; others do
not.  Both types of operating systems have their places/applications.

There are many texts on operating systems.  For further reading, I
cut my teeth on Madnick and Donovan (which is a classic); there is also
a very good book on the internals of UNIX which has come out recently,
and there is a book on microcomputer-based operating systems as well.
I anyone is interested, let me know, and I'll look them up when I get home.

	Rick
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