PCCLOCK DIGITAL CLOCK USER'S GUIDE

                                 Version 2.15d

                     Copyright (c) 1992 Michael J. Sadaway
                             All rights reserved.


                    Please see important information about
                  registering your copy of PCCLOCK and about
               special discounts available to registered users.


Introduction
------------

* PCCLOCK sets your computer's date and time quickly, conveniently, and
  accurately through your modem, by calling the National Institute of Standards
  and Technology's atomic clock in Boulder, Colorado.

* PCCLOCK is a also a full-featured digital clock program that displays the
  date and time in big digits in your choice of 80 colorful designs supplied
  with the program plus up to 20 designs you create yourself.

* Useful as well as fun to watch, PCCLOCK includes manual as well as automatic
  setting, seconds display, 12- and 24-hour modes, an alarm, and an optional
  Big Ben hourly chime.

* Add "PCCLOCK" (or "PCCLOCK AUTO") to your AUTOEXEC.BAT file to check the date
  and time (or set them to the NIST atomic clock) whenever you restart your PC.

* Run PCCLOCK whenever you need to set your computer's clock, or run it just to
  pass the time whenever you and your computer are not otherwise engaged.

* PCCLOCK requires a CGA, EGA, VGA, MCGA, XGA, or compatible color display.  A
  1200-bps (or faster) modem is required for automatic timesetting.


Operation
---------

Pressing the <F1> key alternately displays and erases a list of functions at
the bottom of the screen.  Functions are selected by pressing <F2>-<F10>; these
keys are active whether or not the list of functions is displayed.  When a
function is selected, instructions are displayed if further input is required.

When no other function is selected, the <Page Up>, <Page Down>, <Home>, <End>,
<Ctrl-R>, and left and right arrow keys can be used to select a clock design
just as though <F2> (Select Design) had been pressed.

Pressing the <Esc> key when no function is selected causes the program to exit.

PCCLOCK can also be run in a non-interactive automatic timesetting mode.  If
the "AUTO" command-line option is specified, PCCLOCK calls the NIST atomic
clock, sets the date and time, and exits.  A "PCCLOCK AUTO" command can be
given at the DOS prompt or in AUTOEXEC.BAT or another batch file.


                                    Page 1
Clock Designs
-------------

The date and time are displayed using specified characters from the IBM
extended character set.  One extended character, called "Mark Char", is used to
form the big digits.  Another extended character, called "Space Char", is used
to form the surrounding box.  Separate foreground and background colors can be
specified for both extended characters.  Thus, six parameters specify a
complete design.

The clock designs are organized into five pages of 20 designs each.  Four pages
are filled with the 80 designs supplied with the program.  The fifth page is
initially blank and may be used to store up to 20 of your own designs.

When PCCLOCK is started, it either chooses a design at random or uses a
specified default design.  To select another design or to select either a
random design or a specific design as the default, press <F2> (Select Design),
and follow the displayed instructions.

To create a design of your own or to modify any of the 100 designs, first
select the design you wish to modify, then press <F3> (Modify Design).  Follow
the displayed instructions to change any or all of the design's six parameters.

The Select Design and Modify Design functions also have options to erase a
design and to restore a design's parameters to either their original values or
to the values saved during a previous run of the program.


Setting Date and Time
---------------------

If you have a compatible modem, PCCLOCK can set your computer's date and time
by calling the atomic clock at the National Institute of Standards and
Technology (NIST, formerly NBS, National Bureau of Standards) in Boulder,
Colorado.  The call usually takes only a few seconds (always less than a
minute) and costs very little (13 to 24 cents from Boston with AT&T).

Before you use PCCLOCK's modem timesetting function, you should review and may
need to modify its modem timesetting configuration parameters.  Refer to
"Configuration" below for details.

To set the date and time by modem, run PCCLOCK and press <Ctrl-S>, or run
PCCLOCK with the "AUTO" command-line option.  Commands sent to your modem by
PCCLOCK, result codes returned by your modem, and data received from NIST are
displayed in a window at the top of your screen.

If the call is successfully placed and valid data is received from NIST, both
the date and time are set, the call is terminated, and the window is closed.
The date and time are adjusted for the time zone specified in your
configuration.  If Daylight Saving Time is observed in your area (as specified
in your configuration) and Daylight Saving Time is in effect (as determined
from the data from NIST), the time (and possibly the date) are adjusted
accordingly.

If the call is not successfully placed, a modem result code (e.g., "BUSY") will
be displayed.  Press <Esc> to cancel the call, and, if you wish, press <Ctrl-S>
to try again.

                                    Page 2
If the data received from NIST is not valid (e.g., because of a noisy line), an
error message will be displayed, and PCCLOCK will remain on-line until it
receives valid data, until a timeout period of 90 seconds is exceeded, or until
you press <Esc> to cancel the call.

When PCCLOCK is run with the "AUTO" option, it displays a message indicating
the success or failure of the call to NIST.  If the date and time are not set
successfully, PCCLOCK creates a file named "PCCLOCK.ERR" in the default
directory.  If the date and time are set successfully, it deletes this file.
In a batch file, the command "IF EXIST PCCLOCK.ERR . . ." can therefore be used
to determine the outcome of a preceding "PCCLOCK AUTO" command.

To set the date or time manually, press either <F7> (Set Date) or <F8> (Set
Time), and follow the displayed instructions.


All About Your Computer's Clock(s)
----------------------------------

DOS maintains a "system date" and "system time", which can be read and set with
the DOS DATE and TIME commands.  The system date and time settings are lost
whenever your computer is powered off and must be reset each time the computer
is restarted.

Many computers have a battery-operated "permanent clock" that keeps the date
and time when the computer is turned off.  IBM PC AT, AT-compatible, and newer
computers have these clocks built-in.  Other computers may be equipped with an
add-on clock that plugs into an expansion slot or with a "slotless" clock that
plugs into a socket under a ROM chip or other socketed chip on the computer's
motherboard.

If your computer has no permanent clock, you need to set the date and time
every time you restart your computer.  You can make this less tedious by
running PCCLOCK from your AUTOEXEC.BAT file and using either its automatic or
manual timesetting functions.

If your computer does have a permanent clock, the system date and time are set
from the permanent clock when the system is restarted.  With a built-in clock,
this is done automatically.  With an add-on or slotless clock, you may need to
run a program from AUTOEXEC.BAT; refer to the documentation supplied with the
clock.  If you also run PCCLOCK from AUTOEXEC.BAT, PCCLOCK should, of course,
be run following this program.

If your computer has a built-in permanent clock, setting the date and/or time
with PCCLOCK will set the permanent clock as well as the system date and time,
regardless of the version of DOS you are using.  (Prior to DOS version 3.3, the
DOS DATE and TIME commands set only the system date and time, not the permanent
clock.)

Some add-on and slotless permanent clocks come with a device driver that sets
the permanent clock whenever the system date or time is set.  If you have such
a device driver installed, setting the date or time with PCCLOCK will also set
the permanent clock.  If not, after setting the system date and/or time with
PCCLOCK, you will need to run the program supplied with your clock to set it as
well.



                                    Page 3
Configuration
-------------

To review or modify PCCLOCK's modem timesetting parameters, shown in Table 1,
press <Ctrl-C>, and follow the displayed instructions.

+---------------+---------------------+---------------------------------------+
| Parameter     | Default Value       | Possible Values                       |
|===============+=====================+=======================================|
| Serial Port   | COM1                | COM1, COM2, COM3, COM4                |
|---------------+---------------------+---------------------------------------|
| Init          | ATZ|~~ATE1M1QV1|~~  | See text.                             |
|---------------+---------------------+---------------------------------------|
| Dial          | ATDT1-303-494-4774| | See text.                             |
|---------------+---------------------+---------------------------------------|
| Hang Up       | ~~+++~~ATH|         | See text.                             |
|---------------+---------------------+---------------------------------------|
| Time Zone     | Eastern             | Atlantic, Eastern, Central, Mountain, |
|               |                     | Pacific, Yukon, Alaska-Hawaii,        |
|               |                     | Bering, Universal                     |
|---------------+---------------------+---------------------------------------|
| DST Observed  | Yes                 | Yes, No                               |
|---------------+---------------------+---------------------------------------|
| UTC Offset    | 0                   | See text.                             |
|---------------+---------------------+---------------------------------------|
| Serial I/O    | Interrupt-driven    | Interrupt-driven, Polled              |
+---------------+---------------------+---------------------------------------+

                      Table 1.  Configuration Parameters


"Serial Port" specifies the port to which your modem is connected.  PCCLOCK
displays the I/O address it has determined for the port in parentheses after
"COMn".  PCCLOCK will not work if the I/O address is incorrect.  The I/O
address should be correct for "standard" configurations; however, nonstandard
configurations may require special consideration:

1.  Like DOS, but unlike some communications software packages, PCCLOCK does
    not include unimplemented ports in its numbering scheme.  For example, if
    your PC has two ports, one at I/O address 3F8h and one at 3E8h, the