Screen Saver
Version 4.4

Screen blanker and security software

REFERENCE DOCUMENTATION




Tom R. Donnelly
P.O. Box 3856
San Dimas, CA
91773























Copyright (c) 1990 Tom R. Donnelly All Rights Reserved

TABLE OF CONTENTS 1
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LICENSE AGREEMENT........................................ 2

REGISTRATION, PROBLEM REPORTING AND USER SUGGESTIONS..... 3

PROGRAM DESCRIPTION...................................... 4

MACHINE REQUIREMENTS AND INSTALLATION.................... 5

OPERATION OF RESIDENT PROGRAM............................ 6

OPERATION OF INSTALLATION PROGRAM........................ 7

HOT-KEYS THAT MAY BE USED................................ 10

MOUSE-RELATED PROBLEMS................................... 11

PROGRAM HISTORY.......................................... 12

REGISTRATION FORM........................................ 13

SITE LICENSE FORM........................................ 14

LICENSE AGREEMENT ...2
========================================================================


This program and the accompanying documentation are the copyrighted
property of Tom R. Donnelly. You are granted a limited license to
use, copy and distribute the program and its documentation, provided
that the following conditions are met.

1. No fee is charged for the use, copying or distribution of the
program and documentation.

2. The program is distributed in its original and unmodified state
along with the original and unmodified documentation.

3. The program is not distributed, in whole or in part, as part of
any commercial product or service without the express written
permission of Tom R. Donnelly.

THIS LICENSE IS EFFECTIVE UNTIL TERMINATED. YOU MAY TERMINATE THE
LICENSE AT ANY TIME BY DESTROYING ALL COPIES OF THE PROGRAM AND ITS
DOCUMENTATION.

YOU MAY NOT USE, COPY, MODIFY OR DISTRIBUTE THE PROGRAM OR
DOCUMENTATION OR ANY COPY, MODIFICATION OR PORTION OF THE PROGRAM OR
DOCUMENTATION EXCEPT AS EXPRESSLY PROVIDED FOR IN THIS LICENSE.

VIOLATION OF ANY LICENSE PROVISION AUTOMATICALLY TERMINATES YOUR
LICENSE AND MAY SUBJECT YOU TO CIVIL AND/OR CRIMINAL LIABILITY.

THIS PROGRAM IS PROVIDED "AS IS" WITH NO WARRANTY OF ANY KIND EITHER
EXPRESSED OR IMPLIED INCLUDING BUT NOT LIMITED TO ANY WARRANTY OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE
RISK AS TO THE SUITABILITY, QUALITY AND PERFORMANCE OF THE PROGRAM IS
WITH YOU. IN THE EVENT THAT THE PROGRAM SHOULD PROVE TO BE DEFECTIVE
YOU ASSUME THE ENTIRE COST OF ALL NECESSARY SERVICING, REPAIR AND/OR
CORRECTION.

IN NO EVENT WILL TOM R. DONNELLY BE LIABLE TO YOU OR ANY OTHER PARTY
FOR ANY DAMAGES, INCLUDING LOST PROFITS AND/OR ANY OTHER INCIDENTAL
OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
THE PROGRAM EVEN IF TOM R. DONNELLY HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.


REGISTRATION, PROBLEM REPORTING AND USER SUGGESTIONS ...3
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This program is distributed under a concept know as "shareware".
ShareWare allows you to use the program and determine if it suits
your needs before you pay for it. Instead of directly advertising
this program, which would require that the price of the software be
substantially higher, the shareware distribution concept allows me to
reduce its costs and price the program accordingly.

After you have determined that the program meets your needs, you are
requested to register your use of the program. A product
registration form is provided at the end of this document.

As a registered user, you are entitled to free upgrades and technical
support for a period of one year from date of registration.
Registered users will also be notified of new releases and will be
entitled to discounts on other products. Your registration fee will
make new development possible.

Quality software is my number one concern. If this product is
broken, I am interested in fixing it, if possible. Registered users
may submit problem reports to the address below. For faster problem
resolution, I may be contacted on CompuServe via EasyPlex. Please
provide your name and registration number and a description of the
problem. You will be assigned an incident number and will be
contacted as soon as a correction is available.

If you have any suggestions for improvements in this product or ideas
for additional features, I am very interested in hearing them.
Please jot them down and send them to me at the address below.



Tom R. Donnelly
P.O. Box 3856
San Dimas, CA 91773

Compuserve Id: 73200,1323


PROGRAM DESCRIPTION ...4
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Screen Saver is a utility designed to "shut off" the video image
produced by your monitor during idle periods. This protects the
screen from "burn-in", a phenomenon that causes a screen image to be
permanently etched into the phosphor of the monitor, even after the
it has been shut off. Pressing any key will restore the image
exactly as it was.

The program also allows you to manually blank the screen. This is
very helpful if you are doing sensitive work and you are subject to
people interrupting you. You can simply press the "hot-key" and your
screen image will "disappear", to be recalled at the touch of any
key.

Screen Saver includes an optional passive security lock. After a
prescribed interval, the keyboard will lock. This will prevent
anyone from issuing commands until the proper password has been
entered. This is NOT intended as a total security system. It cannot
prevent someone from throwing "the big red switch" and re-powering up
your computer. However, it can be an aid in preventing a casual
intruder from disturbing your 7-hour spreadsheet recalculation.

Screen Saver consists of two programs: An installation program
(SCSAVINS.EXE), used to select various default options, and a
resident program (SCSAVER.COM). The installation program should be
run first to select the desired options. These defaults are saved in
a file called SCSAVER.DAT. The resident program should be included
in your AUTOEXEC.BAT file, so that it is run each time your system is
booted. The resident program will take up less than 2K of memory.

The resident program may also be run from the command-line after
booting. This allows you to change options (such as ON, OFF or LOCK,
described below) or immediately incorporate new defaults selected by
the installation program. Any time SCSAVER is run from the
command-line, it will determine if it is already resident. If it is
not resident, it will make itself so. If it is already resident, it
will replace the parameters in the resident copy.

In most cases, it is NOT necessary to reboot your computer to install
new default options.


MACHINE REQUIREMENTS AND INSTALLATION ...5
========================================================================

Screen Saver supports the following hardware and software:

IBM PC, XT, AT, PS/2 or 100%-compatible computer.
MDA, CGA, EGA or VGA adaptor and monitor.
40K of temporary free memory for the installation program.
2K of free memory for the resident program.
MS or PC-DOS 2.0 or later.
Mouse drivers by Microsoft, Mouse Systems or Logitech.


To install Screen Saver, perform the following steps:

1. If installing to a hard disk, copy the Screen Saver files
to any directory included in your PATH statement.

2. Run SCSAVINS and select desired options (detailed
information on SCSAVINS is described later in this
document).

3. Edit your AUTOEXEC.BAT file using a straight ASCII
editor such as KEDIT, EDLIN or SideKick Notepad. Most word
processing programs such as WordPerfect are NOT suitable
for this purpose. Add the command SCSAVER ON or SCSAVER
LOCK (refer to the section "OPERATION OF RESIDENT PROGRAM"
for details about the ON and LOCK options). The command
should be placed after your mouse driver (if you use one)
and before programs such as SideKick. This will load the
resident program each time you computer is booted.

4. Reboot your computer by pressing CTL-ALT-DEL.


OPERATION OF RESIDENT PROGRAM ...6
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The resident program (SCSAVER.COM) should be run from your
AUTOEXEC.BAT file. This will insure that Screen Saver is loaded each
time your computer is started.

If you area using a mouse or mouse-compatible trackball, you should
run Screen Saver AFTER the mouse driver program has been loaded.

SCSAVER [ON|OFF|LOCK|BLANK n]

ON: Specifies that the timer-driven blanking system is to be turned
on. The interval that will be used is that selected during install.
The ON option also disables security locking. If the program is
not yet resident, this is the default if no command-line option is
specified.

OFF: Specifies that timer-driven blanking and/or locking is to be
turned off.

LOCK: Specifies that the timer-driven blanking system AND the
timer-driven security keyboard locking system is to be turned on (ie,
LOCK implies ON and includes security locking). The security locking
interval and password are selected during install. If no password
was selected during install, locking will not occur.

BLANK n: Specifies that the screen is to be blanked in n seconds.
The n parameter is optional and defaults to 2. This normally gives
the system enough time to finish any video output before the screen
is blanked (since any video output will reset the blanking
count-down). This parameter may be any numeric value between 1 and
999 seconds. It is intended to be used from a batch to blank the
screen during set-up of some unattended system. Note that, in order
to use the BLANK parameter, the Screen-Saver system must have been
previously loaded with either the ON, OFF or LOCK option.


After the resident program has been loaded, SCSAVER may be run from
the DOS command line at any time. This allows you to change the
state from ON to OFF or LOCK or to load new options selected by the
installation program, without requiring a reboot. SCSAVER may also
be run from a batch file.


OPERATION OF INSTALLATION PROGRAM ...7
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When you run SCSAVINS, the installation program, you will see a menu
of options. To select an option to change, press the highlighted
number or letter next to the option, or move the mouse-cursor to the
desired item and click the mouse button.

The left mouse button will function as the CR key (accept) and the
right button will function as the ESC key (ignore).

1-Blanking interval

To change the blank interval (the amount of idle time before the
screen automatically blanks), press 1 from the menu. The current
blank interval value will be displayed and you may key in a new
interval value from 1 to 59 minutes.

2-Hot-key for blanking

To change the hot-key (the key that will cause the screen to be
blanked), press 2 from the menu. The current hot-key will be
displayed and you may press a new key combination that will be used
as the blanking hot-key. Some keys are not allowed to be used as hot
keys. The list below shows which keys are eligible to be used as hot
keys.



3-Lock interval

To change the lock interval (the amount of idle time before the
keyboard automatically locks), press 3 from the menu. The current
lock interval value will be displayed and you may key in a new
interval value from 1 to 3600 seconds. You must also enter a
password before locking will occur.

4-Password for lock

To define the password that will be used to unlock the keyboard
after it has been locked, press 4 from the menu. You may then
enter a new unlock password, which will not be displayed as you
type it. When you have typed the new password, press return (or
enter). The installation program will ask you to retype the
password you have entered. This is for verification purposes. If
you mistype the password on either the first or second time, the
password will not be changed.


OPERATION OF INSTALLATION PROGRAM ...8
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5-Restore screen after lock

Password required to restore screen after lock? (currently YES)

Normally, when the LOCK option is in effect and both the lock
interval and the blank interval have expired, the screen will not be
restored until after the correct password has been entered. To allow
the screen to be restored ANY TIME a key is pressed, enter an N for
this option.


6-Ignore screen-restore key

Should key pressed to restore screen be ignored? (currently NO)

Normally, after the screen has been blanked, any key pressed will
restore the screen. The key that was pressed will be passed on to
any application running (or DOS). If you would rather that the key
you press to restore the screen be ignored, enter a Y for this
option.


7-Ignore video when determining inactivity

Ignore video interrupts when determining inactivity? (currently NO)

Some programs constantly update the screen, even when in an idle
state. Frequently, this is to update an on-screen clock or some
other information. Normally, Screen Saver will reset its count-down
timer each time a video request is made. To prevent Screen Saver
from resetting its count-down-to-blanking timer when a video request
is made, press 7 from the menu. The current state of this option
will be displayed. NO means that video requests should reset the
count down timer. This is the default and should work correctly in
most circumstances. If you run a program and find that the screen
does not blank at the selected interval, this option should be
changed to YES.

To change this option, key in a Y or N after selecting the option
from the menu (or click the right mouse button).


OPERATION OF INSTALLATION PROGRAM ...9
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8-Ignore mouse when determining inactivity

Ignore mouse interrupts when determining inactivity? (currently NO)

If Screen Saver has been loaded after your mouse driver program, it
will reset its count-down timers whenever the mouse has been moved or
clicked.

If, for some reason, you want Screen Saver to ignore mouse movement
detection interrupts, set this option to YES. Please note that, if
you have already loaded the resident program with mouse interrupts
ignored, you will have to reboot your computer to enable mouse
movement detection interrupts.

To change this option, key in a Y or N after selecting the option
from the menu (or click the right mouse button).


S-Save changes to SCSAVER.DAT

To save the changes you just made, press S from the menu. The
changes will be written to the file listed on the menu. If Screen
Saver is already resident, you may simply run SCSAVER to have the
changes applied to the resident code. This prevents having to
reboot each time you make a change.

E-Exit without saving

To leave the installation program without saving any changes, press
E from the menu (or ESCape). You will be returned to DOS.


HOT-KEYS THAT MAY BE USED ...10
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The following hot-keys may be used to trigger on-demand screen
blanking. When these keys are defined as hot-keys, they will be
unavailable to any other running programs.

F1 through F10
ShiftF1 through ShiftF10
CtlF1 through CtlF10
AltF1 through AltF10
CtlLeftArrow
CtlRightArrow
CtlEnd
CtlPgUp
CtlPgDn
CtlHome
Alt0 through Alt9
Alt- and Alt=
AltA through AltZ


ACKNOWLEDGEMENTS:

Special thanks to Dixie Swanson for her analysis and design
contributions and for her testing of beta releases. Its not easy
being on the (sometimes) bleeding edge of software technology.


MOUSE-RELATED PROBLEMS ...11
========================================================================


In order to detect mouse activity, Screen Saver must hook the mouse
interrupt (INT33h) after the mouse driver has been loaded. Most
programs have no trouble with this technique, since all requests
coming through INT33 are passed to the mouse driver. However, a
special case occurs when using "menu" programs supplied with some
mouse drivers.

For reasons known only to the mouse manufacturers, these menu
programs not only require the driver be resident, they also require
that it be THEIR driver that is resident. Therefore, Mouse Systems
menu programs won't work with Logitech's driver and Logitech's menu
program won't work with Microsoft's driver and so forth.

Because Screen Saver has replaced the INT33 vector after the mouse
driver was loaded, the menu programs can't find their literal in the
memory around where INT33 points. Therefore, they declare that the
mouse driver is not loaded!

In order for Screen Saver to be compatible with various mouse
drivers, it has adopts some of the same techniques used by the
individual mouse drivers to identify themselves to the menu programs.
These techniques have been tested with the mouse drivers and menu
programs supplied by MicroSoft, Mouse Systems and Logitech. I'm sure
that there are other mouse manufacturers out there that have
implemented yet another egotistical security check scheme. If you
install Screen Saver and start receiving messages about "Mouse Driver
Not Loaded", please be sure to let me know. I want to incorporate as
many of these "non-standard" techniques as possible so as to support
as many different mouse drivers as I can.

LOADING ORDER FOR SCREEN SAVER AND MOUSE DRIVERS

Screen Saver should be loaded after your mouse driver and before any
mouse-menu programs. Here are some sample AUTOEXEC.BAT files
illustrating the loading order:

Echo Off Echo Off
Prompt $p$g Prompt $p$g
mouse MscMouse /A8 /2
ScSaver On ScSaver On
logimenu /12 PopUp
click M_DOS


PROGRAM HISTORY ...12
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Changes in 4.4
* Fixed some documentation errors.

* Corrected the following problems:
SC04301: SCSAVER sometimes doesn't detect mouse movement.
SC04302: SCSAVINS won't change hot-key to NONE.
SC04401: Some programs complain "No Mouse Driver Loaded".

* Improved install program.

Changes in 4.3
* Reworked documentation.

* Added mouse support to installation program and resident program.

* Added install option to prevent mouse interrupts from resetting
blanking timer.

* So as not to be deemed a virus by some vaccination programs,
installation options are now be stored in a separate file, instead
of modifying the .COM file.

Changes in 4.2
* Added install option to allow the key that restores the screen to
be ignored (ie, not passed to application) or honored (passed to
application).
* Made ON the default if no command-line arguments specified.
* Corrected bug where "security lock active" message was not
displayed if LOCK was specified during initial load (even though it
functioned correctly).
* Corrected bug that allowed LOCK to engage, even though no password
was defined.

Changes in 4.1
* Changed hot-key blanking logic so that lock will engage when screen
is blanked via hot-key (if LOCK option is on).
* Added option so that blanked screen will not be restored if lock
has engaged until after password has been entered.
* Reduced resident size by a few bytes.


Changes in 4.0
* Added install option to prevent video interrupts from resetting
blanking timer.
* Allow additional hot-keys for screen blanking.
* Change EGA/VGA detection logic to make detection of monitor type
more reliable.
* Incorporated CPCA logic.
* Minor bug fixes.

Changes in 3.0
* EGA screen blanking now supported.
* New command-line option that will allow the screen to be blanked
on-demand from a batch file.

REGISTRATION FORM Screen Saver Version 4.4 ...13
========================================================================


Registration fee: $20.00


Date: ____/____/____

Name: ________________________________________

Company Name: ________________________________________
(optional)

Address: ________________________________________

City: ____________________ State: ____ Zip: __________

Daytime phone: (______) _________________ Ext: _______

Evening phone: (______) _________________ Ext: _______


Make of Computer: _____________________ Model: ____________

Installed RAM: _________ Disk type: [ ] 5.25" [ ] 3.5"



TERMS: No credit cards, CODs.
Make checks payable to: Tom R. Donnelly
Checks drawn on a U.S. bank in U.S. funds.
International bank or postal money orders in U.S. funds.


Attach check and mail to:

Tom R. Donnelly
P.O. Box 3856
San Dimas, CA 91773

SITE LICENSE FORM Screen Saver Version 4.4 ...14
========================================================================


License fee: 1 copy - $20.00
6-25 copies - $100.00
26-50 copies - $200.00
51-100 copies - $400.00
Unlimited copies - $500.00


Date: ____/____/____

Contact Name: ________________________________________

Company Name: ________________________________________

Address: ________________________________________

City: ____________________ State: ____ Zip: __________

Telephone: (______) _________________ Ext: _______


Number of copies : _____ Amount enclosed: ______



TERMS: No credit cards, CODs.
Make checks payable to: Tom R. Donnelly
Checks drawn on a U.S. bank in U.S. funds.
International bank or postal money orders in U.S. funds.


Attach check and mail to:

Tom R. Donnelly
P.O. Box 3856
San Dimas, CA 91773