RTCLOCK, version 1.31, by Michael Conley
Release date: March 17, 1989

UPDATE:
RTCLOCK version 1.31 adds the option to set the Real Time Clock
from the DOS Clock. In addition, automatic detection of color
display has been added, as well as some minor refinements in the
WWV display routines.

PURPOSE:
RTCLOCK is intended for use on an AT class 80286 or 80386 machine.
It will read the real time clock and set the DOS clock from it,
or read the DOS clock and set the real time clock from it, or it
will allow the user to set BOTH the real time clock and the DOS
clock from the keyboard.

If you own the Heathkit "World's Most Accurate Clock" with a
serial interface, RTCLOCK will allow you to set BOTH your
real time clock and your DOS clock from WWV, the short-wave
time data service provided by the U.S. government.

OPERATION:
Five basic commands are supported, which may be entered either
on the command line or, if no command is specified, from a menu
within the program.

reads the real time clock, and sets the DOS clock.

reads the DOS clock, and sets the real time clock.

sets BOTH the real time clock and the DOS clock from
the keyboard.

sets BOTH the real time clock and the DOS clock from
serial data transmitted by the Heathkit "World's Most
Accurate Clock." Be sure to read SETUP for additional
configuration required for this option.

views the time data from the Heathkit "World's Most
Accurate Clock" until a key is pressed. It does NOT
alter either of the system clocks. Be sure to read
SETUP for additional configuration required for this
option.

SETUP:
Commands , and require NO configuration.

Commands and require the installation of an RS232
serial line from the Heathkit "World's Most Accurate Clock"
to the computer. See the clock manual for wiring information.
Be sure to set the DIP switch inside the clock for the AUTO
mode, which provides CONTINUOUS output from the clock. The
other mode would require manipulating the DTR line to request
clock data, and is NOT supported by the program. Also be sure
to select an appropriate baud rate and program the correct year
using the DIP switches inside the clock.

The program must be informed of the baud rate and the COM port
in either of two ways:

1) You may invoke the program and provide the configuration info
on the command line as follows:

RTCLOCK W COM3 2400 [enter]

Allowable choices here are W or V for the program mode,
COM1 thru COM4 for the data port, and 300, 600, 1200, 2400,
4800, or 9600 for the baud rate. Other choices or missing
info will produce an error message.

2) You may create an ASCII text file (an example is included
in this distribution) with the port and baud rate on the
SAME line. Name this file RTCLOCK.CNF and place it in the
same directory from which the program will be run. An
example of the file contents would be:

COM3 2400

Note: The parameters must be on the SAME line.

Please also note that, if you enter the program with NOTHING on
the command line (i.e., menu mode) you MUST provide RTCLOCK.CNF
in order to use the W or V options, as these cannot be entered
from the menu. A sample RTCLOCK.CNF is included with this
distribution.

SERIAL SETUP:
This release supports COM ports 1 thru 4 and functions entirely
without interrupts. This allows you to avoid the common problem
of "interrupt sharing," where COM1 and COM3 share IRQ4, while
COM2 and COM4 share IRQ3.

We recommend that you set your serial I/O card for NO interrupts
for the port selected for use with RTCLOCK to avoid possible con-
flicts with other serial devices. However, the program will run
properly even in the event that interrupts are present on the port.

CONCLUSION:
Your comments and suggestions are welcome. Please contact the
Charlatan's Cabin BBS (213) 654-7337 and leave a comment to the
Sysop (that's me.)

A brief warning: TEST the clock hookup using a communications
program, such as Qmodem, to verify that it's hooked up and sending
data correctly. RTCLOCK will simply TIME OUT if there is no output
from the clock in the W or V mode.
If the clock IS connected, but it cannot produce the correct time,
the program WILL gracefully exit with a message, so it can safely
be used in a batch file, provided the serial line is present.

Michael Conley