File        : glossary.txt
Date        : 14-Dec-99
Author      :  A.Thoukydides, 1995, 1996, 1997, 1998, 1999, 2016
Description : An explanation of some of the words, terms and abbreviations
              used in this documentation.

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/>.


Binary - A two-state system which can be represented by the digits 0 and 1.
    Digital computers perform information processing, store data and transmit
    information as binary digits.

Bit - Abbreviation for BInary digiT. It is a unit of storage which can takes
    the values 0 or 1.

Byte - A group of 8 bits. This is generally the amount of memory required to
    store a single character.

Data - Synonymous with information but generally used for the representation
    and processing of information by a computer system.

Dynamic area - A dynamic area is a named area of memory created by an
    application. The Tasks window obtained by clicking SELECT on the Acorn
    icon on the icon-bar lists the dynamic areas at the bottom of the window.

Hexadecimal - Numbers in base 16. The digits are 0123456789ABCDEF, where "A"
    to "F" represent the values 10 to 15.

Interrupt - When the control unit stops processing to handle some external
    need, such as performing an input/output task.

Logical address - This is the address that the programs running in the
    computer use to access memory. The hardware in the computer converts the
    logical address into a physical address when required. When virtual
    memory is being used the mapping between logical and physical memory is
    frequently updated as different areas of memory are accessed.

kB - Abbreviation for kilobyte. This is equivalent to 1024 (2^10) bytes.

MB - Abbreviation for megabyte. This is equivalent to 1,048,576 (1024 * 1024
    = 2^20) bytes. This is sometimes used more approximately to refer to 1
    million bytes.

Operating system - Essential systems software which coordinates and controls
    the use of the system's resources. In the Risc PC this is called RISC OS.

Page fault - An access to a page of memory which is not present at that time
    results in an abort on data transfer exception being raised. This is
    termed a page fault.

Physical address - This is the address that is actually used to access a
    particular section of the memory in the hardware of the computer. A
    physical address always references the same part of the same memory chip.

RAM - Random Access Memory. This is the main memory on a chip which allows
    data to be stored and modified; read/write memory is a more apt
    description.

Virtual memory - This is a system which enables disc space to be used to
    simulate extra RAM. It is usually provided as a feature of the operating
    system.

VM - Abbreviation for Virtual Memory.

WIMP - Abbreviation for Windows Icons Menus Pointer. This is a generic term
    for the graphical interface to the computer. On the RiscPC it is sometimes
    called the Desktop.
