Re: Linux isn't an operating system

Harvey Fishman (
Sat, 9 Mar 1996 11:25:41 -0500 (EST)

On 8 Mar 1996, Jurgen Botz wrote:

> Well, most people I've talked to think otherwise. First of all Linux
> is not Unix (just like GNU's not Unix ;-) and most certainly not
> UNIX(tm), and secondly in Unix and Unix-like OSes the kernel is not
> the OS, it's the kernel. The very word "kernel" implies that
> distinction! If the kernel is the kernel of the OS, then how can it
> also be the whole OS?

Because the term "kernel' is not really a Unixism at all. Most modern
operating systems are layered into at least three separable parts - the
kernel, the Basic Input/Output System (BIOS), and the device drivers. For
instance, that is the intent of the four security rings in the Intel
hardware model. Each layer of the O/S operates in its own ring with
increasing privilege and the kernel being the most trusted with the
greatest privilege. Application software operates in the outermost ring.

But Unix has never emerged from the primordial ooze, and remains just an
amorphous blob. If you try to apply modern terms to the dinosaur, you have
the kernel refer to the entire O/S as there is nothing else.

I first learned about operating systems in probably the same time frame as
Richard - mid '50s - and then the 'system' referred to the idea of a
planned way of carrying out the tasks rather than to a collection of
objects. Indeed, the operating system was the design rather than the code
to execute it.


Harvey Fishman | | Sum, ergo cogito.
718-258-7276 |