🚀 go-pugleaf

On Thu, 27 Jun 2002 23:50:44 -0700, Jeffrey Siegal <jbs@quiotix.com> wrote:
> Isaac wrote:
>> The definition I recall from CSC-501 was that that an operating system
>> was the software layered over top of the computer hardware that provided
>> services making it easier to write programs.  Things typically provided
>> by such a system are IO services, support for, multi-tasking and process
>> scheduling, management of storage devices, control of peripherals
>> among other things.
>> 
>> I would consider that to be at least one conventional definition.  It's the
>> one that was in most OS textbooks in the early nineties.  The linux kernel
>> certainly fits that definition.   But of course so might software layered
>> over or used in conjunction with the kernel if people actually write
>> their programs to that layer rather than to the kernel.
> 
> So you're suggesting that if X is an operating system, then some part of
> X, call it Y, is also itself an "operating system" if it "provides
> services making it easier to write programs?"  

That's not quite what I meant.  If you take the example services as things
that an operating system ought to provide, then what I said is that if
component Y provides those services it can be called an operating system,
and if X consists of things which wrap around Y and also things which
provide addtional services, then X is also legitimately called
an operating system.

This allows DOS to be an operating system, as well as Windows 3.1 even
if it runs on top of DOS.  

> That seems absurd for the simple reason that when people usually refer
> to *the* operating system (signular) running on a computer being a
> complete entity with components having other names (device drivers,

Here are a couple of quotes from the Silberschatz, et al book "Operating 
System Concepts"

  "There is also no universally accepted definition of what is part of the OS
  and what is not. A simple viewpoint is that everything a vendor ships when
  you order "the operating system" should be considered.  A more common
  definition is that the operating system is the one program running at all
  times on the computer (usually called the kernel)."

  "An operating system is a program that acts as in intermediary
	between a user of a computer and and the computer hardware."

I think the kernel qualifies as an OS as would the kernel + the glibc.  
OTOH, so does the complete set of software in the Debian distribution.

Isaac