Contents of the TIMESYNC.DOC file
Copyright 1992 SolaComp Software. All Rights Reserved.
DISCLAIMER OF WARRANTY
THIS SOFTWARE AND ANY ACCOMPANYING MANUALS ARE SOLD "AS IS"
WITHOUT WARRANTY OF ANY KIND, EXPRESSED OR IMPLIED. THIS
INCLUDES, BUT IS NOT LIMITED TO, ANY IMPLIED WARRANTY OF
MERCHANTABILITY OR SUITABILITY AND ACCURACY FOR A PARTICULAR
TASK. THE USER ACCEPTS ALL RESPONSIBILITY FOR THE USE AND
CONSEQUENCES ARISING FROM SUCH USE. UNDER NO CIRCUMSTANCES SHALL
THE SELLER BE LIABLE FOR ANY DAMAGES OR COSTS, DIRECT OR
INDIRECT, RESULTING FROM USE OF THIS SOFTWARE.
This program sets the computer's clocks by placing a telephone
call to one of two automated time services. These calls will be
long distance for the majority of users, but will be less than a
minute in length. These time services drop the connection
automatically within a minute of the connection being made.
TimeSync sets the DOS and hardware real time clock with the
current date and time. This information is obtained from a
telephone call to the United States Naval Observatory or the
National Institute of Standards and Technology using a modem
attached to the computer.
The United States Naval Observatory (USNO) is the source of
official time for the United States through its Master Clock.
This time is derived from the average of a number of highly
accurate timepieces based on "atomic" processes such as the
frequency of radiation emitted from cesium under specified
conditions or from a hydrogen maser under specified conditions.
The USNO is responsible for determination and distribution of
precise astronomical and timing data for use in activities such
as navigation, global positioning, and scientific research. The
United States Naval Observatory is located in Washington, D.C.
(telephone area code 202).
The National Institute of Standards and Technology, formerly
the National Bureau of Standards, provides scientific and
technological services including time and frequency standards.
These include radio stations WWV, WWVB, and WWVH, and the
Automated Computer Telephone Time Service (ACTS). To achieve
maximum accuracy, the NIST-ACTS system interactively changes the
timing of its signal based on the round trip time delay between
itself and a caller. If everything works perfectly, the accuracy
of the time signal should be within 2 milliseconds of the
"correct" time. Even if things are not perfect, an accuracy of
10 milliseconds can be achieved by many users. The National
Institute of Standards and Technology Time and Frequency Division
is located in Boulder, Colorado (telephone area code 303).
Several factors limit the accuracy and resolution with which
the time is set within a PC compatible computer. The time signal
is received over a telephone and through a modem. Such things as
the transmission speed, the propagation delay between the
computer providing the time signal and the receiving computer,
and the delays internal to the modem all create some degree of
error from the "correct" time. These errors (the NIST uses a
nominal value of 45 milliseconds) are balanced against the
resolution of the clocks within the computer. The DOS system
time is based on 55 millisecond clock 'ticks' provided by a
hardware timer. The real time clock inside an AT compatible, or
on an add-on card in a PC/XT usually only provides a resolution
of one second.
This program requires an IBM PC/XT/AT or compatible computer
with a 1200 baud modem. A mouse is optional.
If you find this package useful, a registration fee of $7.50
would be greatly appreciated. Send check or money order to:
P.O. Box 4464
Lutherville, MD 21094
Inquiries may be directed to the above address or to User ID
70732,3556 on the CompuServe Information Service.
The following files are included in this package:
TIMESYNC.EXE - The time setting utility
TIMESYNC.DOC - This file
TIMESYNC.HLP - The on-line help file for TIMESYNC
TIMESYNC.ICO - An icon for use in Windows
TIMESYNC.PIF - A sample PIF file for Windows
Installation consists of setting up a directory and copying
the files into it, or simply copying all files into an existing
TimeSync operates in either interactive or batch mode.
The batch mode is accessed using command line options. The
command syntax is:
TIMESYNC /B [ NIST | USNO ]
The "/B" option will select batch operation which simply
uses the current configuration file to make the time call. If
"NIST" or "USNO" is entered on the command line, that time signal
will be used; otherwise, the default time signal saved in the
configuration file will be used.
Interactive mode is the default. Simply enter `TIMESYNC'
from a DOS prompt. The program is menu driven. The menu choices
may be selected either using a mouse or pressing the [ALT] key
and the highlighted letter (use the space for the triple bar
symbol). The [TAB] key is used to move among fields on a form.
Where appropriate, the [ENTER] key is used to accept the current
values and end entry on a form. The "Cancel" selection will
terminate entry on a form without saving any changes which may
have been made.
The top level menu bar contains four selections: (triple
bar), Settings, Call, and Quit.
The Info menu (triple bar symbol) provides access to
selections dealing with system information. The About selection
displays information about the program.
The Settings submenu allows system specific information to
be entered. The selections available are Default service, Time
Zone, Com Port, Modem Strings, Save Configuration, and Reset
The Default service selects either the NIST-ACTS or the USNO
Master Clock as the default time service. This is used if no
parameters are given when executing TimeSync in batch mode.
Time Zone leads to a submenu which allows the user to
specify the time offset from the standard time zone they are
located and UTC (Universal Coordinated Time), also known as GMT.
For instance, Eastern Standard Time is 5 hours behind UTC. If
the "Use Daylight Savings Time" selection is checked, the time
will be adjusted to daylight savings during the proper time of
the year. Areas that do not use Daylight Savings Time incude
Arizona, Hawaii, and the easternmost part of Indiana. The USNO
Master Clock signal does not include information about daylight
savings time, so if the time service selected is the USNO, the
program will assume that daylight savings time is in effect
between the first Sunday in April (2:00 AM local time) until the
last Sunday in October (2:00 AM local time).
The Com Port choice displays a submenu allowing the user to
specify the com port to which the modem is attached.
The Modem Strings selection will allow the user to edit the
modem command and status messages. While the default values
should work for most "AT Command" type modems, the documentation
provided with the modem should be referenced in setting these
messages. Information regarding these commands may also be found
in various communications packages. Some are quite robust and
support for a wide range of modems. One useful addition to the
initialization string is the command "M0" which turns off the
modem's speaker. This may be added before the "^M" at the end of
the initialization string. The "^" (caret) character will cause
the next character to be interpreted as a control character (e.g.
^M is a carriage return). The "~" (tilde) will cause an 0.5
second pause when encountered (this is usually used when
switching the modem into command mode).
The XT Clock Set Command allows the user to specify the DOS
command used to set the real-time clock on a PC or XT computer.
On AT class machines the real time clock is built in, and may be
directly accessed. In XT machines, the real time clock is often
on an add-on card, and each has its own method of setting the
time. The input to this selection should be the DOS command used
to set the clock (e.g. "\util\setclock").
The Save Configuration command saves the configuration in a
file in the same directory as the program.
The Reset Configuration command restores the configuration
to the defaults built into the program.
The Call menu item initiates a time call. The selections
are the two time services which may be used (NIST and USNO).
The final choice is Quit. This command terminates the
program. If the configuration file has not been written and any
items were modified, the user will be prompted to save the