<preface>
<title>Welcome to OS-9!</title>
<titleabbrev>Introduction</titleabbrev>
<para>
The heart of your &make; Computer is an amazing device: the
6809 microprocessor chip. This advanced microcomputer can run the
kind of sophisticated software normally found only on much larger
and costly computers. Because the OS-9 operating system was designed
by the same people who designed the 6809 microcomputer, together
they provide an extremely efficient and powerful combination.
</para>
<para>
The foundation of a computer's software system is its
<emphasis>Operating System</emphasis> or "OS". It is the master control
program that interfaces all other software to the system's hardware. Some
of the things it must do are performing input and output operations,
coordinating memory use, and many other "housekeeping" functions. All
other software - programming languages, applications programs, etc. -
live in your computer's memory along with the OS and depend on it to
communicate with you using the keyboard and display and to store and
retrieve data on disks, etc. Because virtually all other software relies
on the OS, your computer's performance depends on the capabilities and
efficiency of its OS.
</para>

<para>
OS-9's overall structure was based on the famous UNIX<footnote id="unixdesc">
<para>
Unix is an operating system designed by Bell Telephone
Laboratories, which is becoming widely recognized as a standard for
mini and micro operating systems because of its versatility and
elegant structure.
</para>
</footnote>
operating system, which has been widely acclaimed as the operating
system of the future because of its versatility, logical structure,
and friendly user commands. The OS-9 family of advanced software is
not only more powerful than most other microcomputer scftware - it
is also much easier to learn and use.
</para>
<para>
Some of the advanced OS-9 features you'll learn about in this
book are:
</para>
<orderedlist numeration="arabic">

<listitem><para>Friendly Unix<footnoteref linkend="unixdesc">-type
user interface and environment</para></listitem>

<listitem><para>Multiuser/Multitasking Real-Time Operating System</para></listitem>

<listitem><para>Extensive support for structured, modular programming</para></listitem>

<listitem><para>Device-independent interrupt-driven input/output system</para></listitem>

<listitem><para>Multi-level directory file system</para></listitem>

<listitem><para>Fast Random-Access File System</para></listitem>

<listitem><para>Readily Expandable and Adaptable Design</para></listitem>

</orderedlist>
<para>
If you don't know what some of these thing mean yet - don't
worry. As you explore OS-9 you'll soon learn how they enhance the
capability of your &make; Computer and make it so much easier to use
in almost any application.
</para>
<para>
OS-9 has many commands and functions - definitely more than
you can learn in an evening! The best way to become an OS-9 expert
is to study this manual carefully, section-by-section, taking tire
to try out each command or function. Because many functions affect
others, you'll find this manual extensively cross-referenced so you
can skip ahead to help you understand a new topic. Taking the time
to study this book will certainly increase your knowledge and
enjoyment of OS-9.
</para>
<para>
But if you can't wait, at least read the rest of this chapter,
scan the command descriptions in Chapter 7, and have fun
experimenting!
</para>
</preface>