File        : virtualise.txt
Date        : 14-Dec-99
Author      :  A.Thoukydides, 1995, 1996, 1997, 1998, 1999, 2016
Description : Introduction to the documentation for Virtualise.

License     : Virtualise is free software: you can redistribute it and/or
              modify it under the terms of the GNU General Public License as
              published by the Free Software Foundation, either version 3 of
              the License, or (at your option) any later version.

              Virtualise is distributed in the hope that it will be useful,
              but WITHOUT ANY WARRANTY; without even the implied warranty of
              MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
              GNU General Public License for more details.

              You should have received a copy of the GNU General Public License
              along with Virtualise. If not, see<http://www.gnu.org/licenses/>.


INTRODUCTION     

The Virtualise system provides a limited form of virtual memory for RiscPC
dynamic areas. It is composed of two parts: A module which actually provides
the virtual memory, and a front-end which provides an easy to use interface
to most of the features.

The main features are:

    Simple to use WIMP front-end application to control virtual memory.
    The memory usage can be controlled using the bar in the Task Manager.
    Any number of virtual dynamic areas can be created and managed.
    Can create virtual dynamic areas larger than the amount of physical memory.
    Any dynamic area can be converted to/from virtual memory at any time.
    Supports draggable virtual dynamic areas and those with handlers.
    Intercepts OS SWIs to minimize changes required to existing applications.
    Supports memory accesses from USR26 and SVC26 modes.
    Pages may be locked to allow access from interrupt routines.
    Parameters for file operations are automatically locked and unlocked.
    File accesses transparently split to allow operations larger than memory.
    Handles all processor instructions, including coprocessor data transfer.
    Does not affect other programs that use processor hardware vectors.
    Global page allocation policy across all virtual dynamic areas.
    Choice of page replacement policies: NFU with ageing, FIFO or random.
    Whole WIMP tasks can be suspended and swapped to disc.

Read the "tutorial.txt" file for a quick introduction to using Virtualise. The
other parts of the documentation are described below.


LIST OF DOCUMENTATION

The other files in this directory are:

    frontend.txt    Description of the WIMP front-end "!Virtualis".
    
    glossary.txt    An explanation of some of the words, terms and
                    abbreviations used in this documentation.

    module.txt      Details about using and controlling the Virtualise module
                    without the front-end. This also includes some technical
                    details about how the virtual memory operates.
    
    products.txt    Contains information about the use of virtual memory with
                    specific products.

    swis.txt        Description of the SWI interface to the Virtualise module.
                    This is only of relevance to programmers wishing to include
                    support for virtual memory in their own software.

    tutorial.txt    A simple introduction to some of the more useful features
                    of the WIMP front-end.

    versions.txt    The version history for the Virtualise module and
                    front-end. Read this if you are upgrading from an earlier
                    version to discover what has changed.
                
    virtualise.txt  This file.
