Usno.rexx (c) 1989 Steve Poling.  Freely distributable to all, keep it
that way.  Kudos, to Jeremy Farrance who provided critical sections of
code to make usno.rexx work in all situations. 

Usno.rexx was written by Steve Poling as an excercize in AREXX
programming.  The date of this release 1.0 28 aug 89.  You may not
find this program terribly useful if:

 - You have no interest in AREXX
 - You don't own Baud Bandit (it might be converted to VLT, idunno)
 - You refuse to tolerate another program that does what AtomClock does.
   (AtomClock is a Modula-2 program (I haven't seen source) that also calls
   the Naval Observatory.  See section Usno vs AtomClock for more.)

Being something of an astronomy buff I was aware of the US Naval
Observatory's (USNO) various contribution to amateur astronomy for us
computerized folk.  One of the services of USNO is to distribute
accurate time codes.  If you call 1(202)653-0351, a USNO computer will
answer and it will send a series of pairs of lines of the form:

	jjjjj ddd hhmmss UTC 
	*

The actual output is not Js, Xs, etc. but digits.  The meaning of those digits
is as follows:
	jjjjj stands for the 5 least significant digits of the Julian date.
	ddd   stands for the number of days since Jan 1st of this year. 
	hhmmss stands for the Hours Minutes Seconds of right now
The UTC indicates that they aren't talking Washington DC
clock-on-the-wall time.  The UTC is roughly the same as GMT or Zulu
give or take a leap second or two, I think. 

Note that if the USNO changes their format, their phone number or
their baud rate, this program will have to change.  

This is my first rexx program so please be gentle in criticism.

Many times I was confronted with problems, and the only solution I
could find was an ugly, brute force solution.  I hope that some kind
soul will view this code with compassion, and show me a better way to
do some of these things.   (Jeremy was the first such benefactor.)  I
will enumerate the problems and I will incorporate your suggestions in
subsequent releases of Usno.rexx. 

- I never did get DIAL to work, I couldn't tell which BaudBandit commands
  returned status codes or not.  Frustrating as heck.
- I had a SEND command, but no way to GET chars directly from port as
  I wanted.   Had to resort to a RAM file capture.  PULL didn't do
  what I wanted.

Many thanks belong to Art Steinmetz who's program I studied while
writing this one.  (I didn't have source, I saw how it ran.)  More
thanks belong to Jeremy Farrance who offered helpful suggestions and
then Jeremy took my pre-release code and improved it drastically.
Finally thanks go to Jean Meeus who's book Astronomical Formulae for
Calculators provided the algorithm for Julian to calendar date
conversion. 

AtomClock VS Usno.rexx
You are probably wondering how Usno.rexx fits into the eternal scheme
of things.  Expecially since the problem is already, essentially
solved.  I don't think of the two programs as being competitors.  Each
serves a different purpose:

Usno - to teach ME rexx and program interfacing. PERIOD.  It sets the
       	the clock, too.  Maybe teach you something, too?
AtomClock - to set the amigados system clock, and whatever else Art 
	Steinmetz wanted from it.

Relative strengths:

AtomClock - Workbench support.  Critical variables are held in the
tooltypes of the icon, where they can be easily modified.  This is a
superior approach.  I'll bet AtomClock is more accurate and faster.
AtomClock is compiled, to it takes less core, etc. 

Usno.rexx - has none of those things.  The USNO phone number, its baud
rate, the modem control stuff are all hard-coded in the rexx source.
I considered putting in stuff to read those params out of an icon
file, but hey, the language is interpreted.  Everyone's got the
source, people can read comments, they can change it themselves w/o
too much hassle.  I just saved myself the programming to do all that
stuff unrelated to the primary mission of USNO.REXX.  You'll note that
unlike AtomClock, usno.rexx sets the date and year.

I leave as an excercize to the student: Modify USNO.REXX to set the
system hardware clock after it sets AmigaDog's time. 

LAST WORD: (At last!)

I've also provided for your pleasure the programs Julian.rexx and
DeJulian.rexx.  These programs do Julian date conversions in exactly
the reverse of what you'd expect. 

Cheers, 
Steve Poling, 28-Aug-1989, 
47767 241 013150 UTC