Janz Tec emVIEW emWEB-21 User manual

emWEB-21 (Hardware Manual) •Introduction 1 - 1
Rev. 1.1 © Janz Tec AG
Refers to product revision
V 1.0
emWEB-21
Web panel with browser support
(Hardware Manual)
Version 1.1
PROPRIETARY NOTICE
All rights reserved by Janz Tec AG.
No parts of this technical manual may be modified, copied or reproduced
in any form or by any means for commercial use without the prior written
permission of Janz Tec AG, Germany.
All instructions, information and specification contained in this manual
are for reference only and remain subject to change without
announcement.
Preliminary

1 - 2 emWEB-21 (Hardware Manual) •Introduction
© Janz Tec AG Rev. 1.1
Title:
emWEB-21 hardware manual
File:
J:\AS\Entwicklung\Projekte\HW\emPC\emView\12_Zoll\emVIEW_abgesetzt\doc\ma
nual_emview_12td.doc
Pattern:
j:\as\entwicklung\formulare\entwicklung (ew)\ew_manual.dot
Created:
ime, 08.02.2017
Last Update:
tka, 13.07.2021
© Janz Tec AG 2017
Tel.:
[phone]
FAX:
[phone]
email:
[e-mail]
Internet:
www.janztec.com

emWEB-21 (Hardware Manual) •Introduction 1 - 3
Rev. 1.1 © Janz Tec AG
Contents
1 Introduction 7
1.1 Features ...............................................................................................................................7
1.2 Functional Overview ............................................................................................................7
1.3 Safety Instructions ...............................................................................................................8
1.4 Installation and Maintenance ...............................................................................................8
1.5 Ambient and Environmental Conditions...............................................................................8
2 Installation 8
2.1 Dimensions and mounting information ................................................................................9
2.2 Technical specification.......................................................................................................11
2.2.1 DC main power supply..................................................................................................12
2.2.2 Universal serial bus - USB............................................................................................12
2.2.3 Display ..........................................................................................................................12
2.3 Micro SDcard Replacement ...............................................................................................13
2.4 Battery Replacement .........................................................................................................13
3 Operating System and Drivers 14
3.1 Janz Tec AG Linux Image for emVIEW .............................................................................14
3.1.1 Default configurations ...................................................................................................14
3.1.2 Disk Partitioning information .........................................................................................14
3.1.3 Overlay filesystem (AUFS) ...........................................................................................14
3.2 Optional Software...............................................................................................................15
3.2.1 Google Chromium webbrowser ....................................................................................15
3.2.2 Webmin Configuration Webserver................................................................................15
4 Open Source Licensing 17
4.1 Disclaimer ..........................................................................................................................17
4.2 How to obtain the source code ..........................................................................................17
4.3 Software packages ............................................................................................................17
4.4 Verbatim License Texts .....................................................................................................18
4.4.1 BSD 2-clause "Simplified" License ...............................................................................18
4.4.2 BSD 3-clause "New" or "Revised" License...................................................................19
4.4.3 GNU General Public License v2.0 ................................................................................20
4.4.4 GNU Library General Public License v2......................................................24
4.4.5 GNU Lesser General Public License v2.1 ....................................................................30
4.4.6 eCos license version 2.0...............................................................................................36
4.4.7 IBM PowerPC Initialization and Boot Software.............................................................37
Technical Data 38
5 Product History 39
5.1 Manual History ...................................................................................................................39

1 - 4 emWEB-21 (Hardware Manual) •Introduction
© Janz Tec AG Rev. 1.1
List of Figures
figure 1: emWEB-21 measures ................................................................................................................9
figure 2: emWEB-21 drilling template.....................................................................................................10
figure 3: Block diagram for the internal logic ..........................................................................................11
figure 4: Power connector.......................................................................................................................12
Figure 5 Removing and replacing coin cell battery ................................................................................13
Figure 6 - Webmin overview...................................................................................................................16
Figure 7-webmin kiosk mode ...............................................................................................................16
List of Tables
table 1: emWEB-21 dimensions ...............................................................................................................9
table 3: Power connector assignment ....................................................................................................12
table 5: Display specifications ................................................................................................................12

emWEB-21 (Hardware Manual) •Introduction 1 - 5
Rev. 1.1 © Janz Tec AG
About this Manual
This is the hardware manual for the emWEB-21. It gives all necessary information to users and
programmers of the emWEB-21. We have tried to keep it compact, so there are no special sections for
users and programmers. I.e. everything that can be said about the serial port is said in one place
(connector layout, signal levels and programming hints). Users that are not programmers might
therefore only read the first sections (Introduction and Installation), and come back to the detailed
sections when they need special information.
The manual starts with an Introduction to the emWEB-21. This is some prose that describes the
features and architecture of the emWEB-21. You should already know this if you have bought the
board! It then discusses some topics about Installation of the product.
The rest of the manual then covers technical details about the emWEB-21.
Conventions
If numbers are specified in this manual, they will be either decimal or hexadecimal. We use C-notation
to identify hexadecimal numbers (the 0x prefix).
If we refer to low active signal names, they will suffixed by a “#” character.
Some parts of the text are really important. These are visually marked with the following signs:
Some parts of the manual contain notices you have to observe to ensure your personal safety, or to
prevent damage to property. These are visually marked with the following alert symbols:
DANGER
Indicates that death or severe personal injury will result if proper precautions are not
taken.
WARNING
Indicates that death or severe personal injury may result if proper precautions are not
taken.
CAUTION
Indicates that minor personal injury can result if proper precautions are not taken.
NOTICE
Indicates that damage to equipment can result if proper precautions are not taken.
Indicates information that we think you should have read to save your time by avoiding
common problems. Important suggestions that should be followed will also be marked
with this sign.

1 - 6 emWEB-21 (Hardware Manual) •Introduction
© Janz Tec AG Rev. 1.1
Acronyms and Abbreviations
DVI
Digital Visual Interface
ESD
Electrostatic discharge
HMI
Human Machine Interface
LCD
Liquid Crystal Display
LVDS
Low Voltage Differential Signal, Video signal to the TFT display
SVGA
Super Video Graphic Array
SXGA
Super EXtended Graphics Array
TFT
Thin Film Transistor
USB
Universal Serial Bus
UXGA
Ultra EXtended Graphics Array
VGA
Video Graphic Adaptor, Video Graphic Array
XGA
EXtended Graphics Array

emWEB-21 (Hardware Manual) •Introduction 1 - 7
Rev. 1.1 © Janz Tec AG
1 Introduction
emWEB panel devices are designed to simply visualize machine data provided in web pages, either
in pages of a CODESYS web visualization or in web pages of any other web based environment.
emWEB panel devices are based on a Freescale i.MX6 single core ARM processor. It can be supplied
with 24V power and is connected via an Ethernet interface with the machine network.
1.1 Features
•resistive touch screen (PCT optionally)
•24 V DC power supply
•Fan less cooling concept
•Protection rating of the front is IP65
•High grade aluminium front
•Customizable design of the front panel
1.2 Functional Overview
The emWEBs are normally delivered with a touch-screen. And are normally delivered with Debian
Linux.
The power must be supplied by an external power supply. This power supply must be capable to
provide enough power for the emWEB-21. Please refer to the technical specifications section for more
information.

2 - 8 emWEB-21 (Hardware Manual) •Installation
© Janz Tec AG Rev. 1.1
1.3 Safety Instructions
Refer to page 5 for explanation of the warning notice system.
The product described in this documentation may be operated only by personnel qualified for the
specific task in accordance with the relevant documentation for the specific task, in particular its
warning notices and safety instructions. Qualified personnel are those who, based on their training and
experience, are capable of identifying risks and avoiding potential hazards when working with these
products.
1.4 Installation and Maintenance
NOTICE
The product is intended to be used in industrial environments. Typical applications are
process virtualization.
WARNING: Unauthorized Opening
Improper opening of the device may result in substantial damage to the equipment.
Remove power before you open the housing of the product. Do not connect power or
operate the product until you have closed the housing and tightened all screws.
WARNING: Electrical Shock
The IO interfaces (connectors) of the product are only suited to be connected to SELV
circuits. Use interfaces (connectors) for their intended use only.
1.5 Ambient and Environmental Conditions
WARNING
This product does NOT fulfil the requirements for a fire enclosure according to EN
60950-1 in all possible mounting positions. In these mounting positions, installation is
only permitted above concrete or other non-inflammable materials.
NOTICE: Damage
Do not operate the product beyond the specified ambient conditions. Do not cover the
vent slots of the product.
2 Installation
When opening the shipping package of the emWEB-21, the contents of the package should be
checked immediately.
DANGER: Electrical Shock
Danger to life.
This product operates with 14..32 V DC. Do not connect this product to an improper
power supply.
DANGER: Explosive Risk
This product is NOT designed to be used in potentially explosive atmosphere.
Do not operate this product in potentially explosive atmosphere.
NOTICE: EMI
This product is a class A device. This product may cause radio interference. In this case
the user must take adequate measures.

emWEB-21 (Hardware Manual) •Installation 2 - 9
Rev. 1.1 © Janz Tec AG
The emWEB-21 is delivered in a configured state, but the configurations can be adjusted by the user
as well. To adjust the emWEB-21s configuration, an OSD (On Screen Display) is installed and
controllable by buttons at the backside.
The package also contains a terminal plug for the power connector. The emWEB-21 needs a power
source in between 14 to 30V DC for operation.
The installation of this equipment is allowed for qualified service personnel, only.
Auxiliary existing rules for installation of electrical equipment must be attended to.
2.1 Dimensions and mounting information
figure 1: emWEB-21 measures
The needed cut-out measures are given in figure 2. The overall front panel dimensions are denoted
with W and H. D is the depth of the case. The front has 8 mm thickness.
W
H
D
570.1 mm
366.7 mm
33.6 mm
table 1: emWEB-21 dimensions
W
H
D

2 - 10 emWEB-21 (Hardware Manual) •Installation
© Janz Tec AG Rev. 1.1
figure 2: emWEB-21 drilling template*†
*Not to scale
†Refers to drawing drill_jig_emw12_rev0

emWEB-21 (Hardware Manual) •Installation 2 - 11
Rev. 1.1 © Janz Tec AG
2.2 Technical specification
The emWEB-21 has three connectors, the main power supply, an USB connector and an Ethernet
connector. Optionally a CAN connector is orderable. The figure 3 shows a block diagram of the
internal function.
figure 3: Block diagram for the internal logic

2 - 12 emWEB-21 (Hardware Manual) •Installation
© Janz Tec AG Rev. 1.1
2.2.1 DC main power supply
The Power unit (figure 3) is energizing all internal components, the display and its backlight. Thereby
the power supply can vary in between 14 to 32 VDC. The emWEB-21 has a power dissipation with
less than 9 W. Before connecting the DC main power supply the protective bonding conductor (PE)
must be connected.
The power connector is included in delivery. The assignment of this connector is shown in figure 4 and
table 2.
Pin
Description
1
+ 14..32 VDC
2
NC, do not connect
3
GND
figure 4: Power connector table 2: Power connector assignment
2.2.2 Universal serial bus - USB
To connect the touch-screen to a host computer the USB can be used, too. The connector is USB
Type B, so a standard USB Type A to Type B cable can be used to connect the touch-screen with the
host.
The length of USB cable must not exceed 5 m.
2.2.3 Display
The panel is built as a thin film transistor liquid crystal display TFT-LCD with a diagonal screen of
21.5’’ and up to 16.7M colours.
Description
Specification
Display area
476.64 x 268.11 mm
Number of dots
1920x3 (H) x 1080 (V) (RGB vertical stripe)
Pixel Pitch
0.2483 (H) x 0.2483 (V)
Brightness
300 (Cd/m²) typ.
Viewing angles
-89° to 89° (H), -89° to 89° (V) typ.
Contrast
5000:1 (typ.)
Backlight
LED
table 3: Display specifications
1
2
3

emWEB-21 (Hardware Manual) •Installation 2 - 13
Rev. 1.1 © Janz Tec AG
2.3 Micro SDcard Replacement
NOTICE
Power must be turned off before removing or inserting the micro SDcard
To replace the micro SD card, remove all screws located on the rear panel. After liftifing up the
housing, you can access the Micro SD card slot.
2.4 Battery Replacement
CAUTION
The installed computer board is equipped with a Lithium battery.
Danger of explosion if battery is incorrectly replaced. Replace only with battery of the
same or equivalent type (3-volt lithium coin cell battery).
•Do not attempt to recharge the battery.
•Do not disassemble, crush, puncture, short external contacts, or dispose of
in fire or water.
Compatible battery type: CR2032 (3 Volt lithium coin cell battery)
The battery is used for backing up the system time when the power supply is removed.
1. Turn off the computer properly through the operating system, then turn off any
external devices.
2. Disconnect the power supply from the power inlet and disconnect any external
devices.
3. Disassemble the housing by removing the located screw on the back side and lifting
up the housing. Then locate the battery on the Janztec board.
4. Remove the battery from the holder (See figure 5)
5. Insert the new battery (See figure 5)
6. Re-assemble the housing
Figure 5 Removing and replacing coin cell battery
1. Removal: Insert screwdriver at right side and bend so that the battery
pops outs. Use only gentle force, otherwise the battery holder might be
damaged.
The use a plastic tool is preferred to avoid shorting the battery
2. Insertion: Align new battery to the left side of the holder and gently
press down on the right side of the battery until the battery snaps into
the holder.

3 - 14 emWEB-21 (Hardware Manual) •Operating System and Drivers
© Janz Tec AG Rev. 1.1
3 Operating System and Drivers
When you order the emWEB-21 with pre-installed software (Debian 8 operating system), then our
default Janz Tec image is pre-installed on the µSD-card and the emWEB-21 driver package is already
installed and fully configured.
3.1 Janz Tec AG Linux Image for emWEB-21
Our pre-installed Janz Tec AG Image contains the combination of the official Debain operating system
as well as our emWEB-21 drivers. File /root/imageversion.txt contains the image name and version of
the installed Janz Tec image.
You can change the emWEB-21 configuration on accessing the local hosted website at
http://127.0.0.1/
The local running web service is named “webmin” (http://www.webmin.com) and gives through a web
interface access to different configuration features on the emWEB-21. Please refer to chapter 3.2.2
Webmin Configuration Webserver Webmin Configuration Webserver for further configuration
information.
An additional Janz Tec image feature is a write protected root filesystem. The AUFS filesystem is
integrated to the custom kernel and enabled in the Debian 8 distribution. For further usage
instructions, please have a look at chapter 3.1.3 Overlay filesystem (AUFS).
3.1.1 Default configurations
The emWEB-21 is delivered with an enabled ssh service. During the first start, the SSH keys will be
created. Following the log in credentials are listed, but please note, that the access for the “root”
user is denied for SSH connections.
Default log in credentials:
Username: dev
Password: dev1
Username: root
Password: root1
3.1.2 Disk Partitioning information
Depending on the installed µSD card, the drive has 3 partitions:
- /dev/mmcblk0p1: Boot Partition (not mounted)
- /dev/mmcblk0p2: Linux System Partition (write-protected)
- /dev/mmcblk0p3: Data Partition (read-write)
omounted to /data/ use this partition for user data
3.1.3 Overlay filesystem (AUFS)
Note: The overlay filesystem is default enabled on your system. This prevents data loss on the local
system partition.
In the case of the enabled filesystem protection, all data written to the “Linux System Partition”
(/dev/mmcblk0p2) will be lost during the next restart of the system. The /data folder can be used to
save user specific data. Use the following commands to configure the behaviour of the overlay
filesystem:

emWEB-21 (Hardware Manual) •Operating System and Drivers 3 - 15
Rev. 1.1 © Janz Tec AG
Using reboot-commit will write all changes to write-protected system partition.
commit:
dev@emWeb-aimx6: sudo reboot-commit
enable:
dev@emWeb-aimx6: sudo reboot-ro
disable:
dev@emWeb-aimx6: sudo reboot-rw
For production environment, we recommend that the write-protection of the system
partition is enabled!
NOTICE
To reduce the risk of losing information stored in files on the µSD-card, especially when
writing to the card during a power failure event, consider the use of an external UPS
(uninterruptable power supply).
3.2 Optional Software
This chapter lists and describes additional installed software in the Janz Tec AG default image for the
emWEB-21.
3.2.1 Google Chromium webbrowser
The used web browser is Chromium with the installed version 51.0.2704.79. Additional packages for
the Chromium browser are:
- chromium-codecs-ffmpeg
- chromium-codecs-ffmpeg-extra
- Janz Tec Chrome Extension (for automatically redirect the NewTabPage to the webmin
configuration page.
3.2.2 Webmin Configuration Webserver
Webmin version 1.820 is preinstalled. “Webmin is a web-based interface for system administration for
Unix. Using any modern web browser, you can setup user accounts, Apache, DNS, file sharing and
much more.” For more information have a look at http://www.webmin.com/
Following features are supported on the emWEB-21:
- Show recent system information
- Change of the passwords
- Kiosk mode configuration
- Linux Firewall rules
- Network configuration
- System time
- Touchscreen calibration

3 - 16 emWEB-21 (Hardware Manual) •Operating System and Drivers
© Janz Tec AG Rev. 1.1
Figure 6 - Webmin overview
On the first boot the system has to be configured for the kiosk mode. This includes to define a default
homepage which should be loaded after starting the operating system.
For configuring the kiosk mode, open the “Kiosk Configuration” page on the webmin service. Have a
look to Figure 7. After setting up the homepage, note that the changes has to be committed to the
filesystem. Choose the “reboot-commit now” button to apply the configuration.
Figure 7- webmin kiosk mode
Once the kiosk mode is enabled and a default page is shown at the start up, there are following ways
to (re-)configure the emWEB-21.
1. GUI based modification
Apply a keyboard to the emWEB-21 and press “Ctrl” + “Shift” + “T”. This opens a
new browser tab and show the navigation bar. Open “http://127.0.0.1/”
2. Command line based modification
Apply a keyboard to the emWEB-21 and press “Ctrl” + “Alt” + “F1” (Alternatively
open a SSH shell).
After pressing, a shell will appear and gives access with the specified credentials. For
modifying the homepage, edit the file “/etc/kiosk.conf”

emWEB-21 (Hardware Manual) •Open Source Licensing 4 - 17
Rev. 1.1 © Janz Tec AG
4 Open Source Licensing
This product uses a number of open source software packages which are listed below. The open
source software is provided free of charge. You are entitled to use the open source software in
accordance with the respective license conditions as provided in the following chapters.
4.1 Disclaimer
The open source software is distributed WITHOUT ANY WARRANTY; without even the implied
warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. The respective
licenses may contain more details
4.2 How to obtain the source code
The software included in this product contains copyrighted software that is licensed under the GPL
and other open source licenses. Copies of those licenses are found below. You may obtain the
complete Corresponding Source code from us:
Open Source Compliance Division
Janz Tec AG
Im Dörener Feld 8
D-33100 Paderborn
Email: [e-mail]
This offer is valid to anyone in receipt of this information.
4.3 Software packages
The software contained in this product makes use of the following open source software packages.
Package
License
u-boot
BSD-2-Clause
BSD-3-Clause
eCos-2.0
GPL-2.0
IBM-pibs
LGPL-2.0
LGPL-2.1
The u-boot software is stored in the SPI flash of the emWEB-21and is required to boot software that is
stored on the CFast, SD card or the internal eMMC.
As the u-boot can be replaced by the skilled end user, we have no control of which version of u-boot is
installed on which device. You can check the u-boot version by checking the u-boot start up
messages. Please indicate this version when you request the source code.
This license Agreement does NOT cover any software that is installed on the CFast, SD card or the
internal eMMC.

4 - 18 emWEB-21 (Hardware Manual) •Open Source Licensing
© Janz Tec AG Rev. 1.1
4.4 Verbatim License Texts
All license texts can be found electronically on http://spdx.org/licenses.
4.4.1 BSD 2-clause "Simplified" License
Copyright (c) <year> <owner> All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
following disclaimer in the documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

emWEB-21 (Hardware Manual) •Open Source Licensing 4 - 19
Rev. 1.1 © Janz Tec AG
4.4.2 BSD 3-clause "New" or "Revised" License
Copyright (c) <year> <owner> . All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
following disclaimer in the documentation and/or other materials provided with the distribution.
3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote
products derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

4 - 20 emWEB-21 (Hardware Manual) •Open Source Licensing
© Janz Tec AG Rev. 1.1
4.4.3 GNU General Public License v2.0
GNU GENERAL PUBLIC LICENSE
Version 2, June 1991
Copyright (C) 1989, 1991 Free Software Foundation, Inc.
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not
allowed.
Preamble
The licenses for most software are designed to take away your freedom to share and change it. By contrast, the
GNU General Public License is intended to guarantee your freedom to share and change free software--to make
sure the software is free for all its users. This General Public License applies to most of the Free Software
Foundation's software and to any other program whose authors commit to using it. (Some other Free Software
Foundation software is covered by the GNU Lesser General Public License instead.) You can apply it to your
programs, too.
When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are
designed to make sure that you have the freedom to distribute copies of free software (and charge for this service
if you wish), that you receive source code or can get it if you want it, that you can change the software or use
pieces of it in new free programs; and that you know you can do these things.
To protect your rights, we need to make restrictions that forbid anyone to deny you these rights or to ask you to
surrender the rights. These restrictions translate to certain responsibilities for you if you distribute copies of the
software, or if you modify it.
For example, if you distribute copies of such a program, whether gratis or for a fee, you must give the recipients
all the rights that you have. You must make sure that they, too, receive or can get the source code. And you must
show them these terms so they know their rights.
We protect your rights with two steps: (1) copyright the software, and (2) offer you this license which gives you
legal permission to copy, distribute and/or modify the software.
Also, for each author's protection and ours, we want to make certain that everyone understands that there is no
warranty for this free software. If the software is modified by someone else and passed on, we want its recipients
to know that what they have is not the original, so that any problems introduced by others will not reflect on the
original authors' reputations.
Finally, any free program is threatened constantly by software patents. We wish to avoid the danger that
redistributors of a free program will individually obtain patent licenses, in effect making the program
proprietary. To prevent this, we have made it clear that any patent must be licensed for everyone's free use or not
licensed at all.
The precise terms and conditions for copying, distribution and modification follow.
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0. This License applies to any program or other work which contains a notice placed by the copyright holder
saying it may be distributed under the terms of this General Public License. The "Program", below, refers to any
such program or work, and a "work based on the Program" means either the Program or any derivative work
under copyright law: that is to say, a work containing the Program or a portion of it, either verbatim or with
modifications and/or translated into another language. (Hereinafter, translation is included without limitation in
the term "modification".) Each licensee is addressed as "you".
Activities other than copying, distribution and modification are not covered by this License; they are outside its
scope. The act of running the Program is not restricted, and the output from the Program is covered only if its
contents constitute a work based on the Program (independent of having been made by running the Program).
Whether that is true depends on what the Program does.
1. You may copy and distribute verbatim copies of the Program's source code as you receive it, in any medium,
provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice and