 Check out the bookstore at IRBS.com |
|
|
|
|||||
|
||||||
Subject: RAM vs. ROM for Celestial Calculators
From: Luis Soltero (lsoltero@XXX.XXX)
Date: Tue Jan 04 2000 - 17:10:12 EST
Hi Everyone,
This is my first posting so I hope it goes well. A few weeks ago while
perusing the
roninhouse navigation list archive I ran into a series of postings concerned
with the
RAM vs ROM issue in celestial calculators. At the time I was not a member
of
the mailing list so I sent the following e-mail to Bill Murdoch. Anyway, I
think
my mail mesg to Bill is of general interest so I include it here.
Thanks,
--luis
Hi Bill,
This is Luis Soltero the author of the Starpath StarPilot.
It was fun discovering a fellow navigator who has implemented
celestial stuff on the TI calculator series. Prior to my most recent
search on the net I was under the impression that I had been the
only one.
I started the StarPilot project in the summer of 96 and implemented
early versions on the TI-80, TI-81, TI-82 and TI-83. At one point I
released into the Share Ware domain a preliminary version called NavTI-8X
which ran on both the 86 and 82. These products have both been
retracted from the SW since I no longer have time to support them.
Anyway, There are a few items in your e-mail
( http://www.irbs.com/lists/navigation/1999/0918.html) that I would like
to clarify. Since I dont know how to subscribe to the navigational
e-mail list I thought I would write directly to you. It would be great
if you could post this for me.
The key sequence for finding the version number on the 86 is
[2nd][mode][alpha][s]
if at this time you hit [enter] the memory will be erased. It is very
unlikely that anyone will hit this sequence by accident.
Unlike the 82, the 86 will print a mesg on the screen when the 4AAA
batteries get low. Like the 82 the screen gets dimmer as the batteries
loose charge requiring you to increase the brightness of the display
with [2nd][up arrow]. When the brightness level hits 8 or so the
calculator will print a mesg on the screen to tell you to change out
the batteries. The unit will not run on the lithium battery alone. The
lithium battery is strictly used to backup the memory if the main
batteries go dead. The battery systems are totally independent and
the AAAs can be left out of the unit for an extended period without
impacting the charge of the Lithium backup battery or loosing memory.
As you know the 4AAA batteries last for ever. I purchased my
TI-86 in 1997 have used it extensively in the development of
the StarPilot product and on average change out the AAA batteries
once a year. Only 3 sets of batteries have been used in the complete
development of the product and I use my unit A LOT!
To reset the memory on the calculator you must execute
[2nd][mem][f3][f1][f4].
Again unlikely to happen by accident.
Starpath encourages customers to buy the Ti GraphLink cable by selling them
at a reduced price ($19.95) In the very unlikely event of memory loss you
can reload the software from any computer. This could be done from an
internet
cafe any where in the world by simply hooking up the cable to the system.
The
TI Graph Link software as well as the StarPilot is available for download
over
the internet at NO cost i.e. for Free.
AAA batteries are readily available world wide unlike the CR... Li batteries
(used
exclusively in some of the ROM based celestial calculators) which
can be difficult to find in the 3rd world. I have even purchased batteries
in Kuna Yala
San Blas Panama where roads, electricity and the wheel have not yet been
discovered.
Another strong point for the 86 is that it is readily available world wide.
So, if you happen to
drop the thing in the water during the Americas Cup 2000 in Australia,
simply walk down
to the local TI reseller buy a new one, stop by the Internet cafe on the way
back to your
boat and you are in business. Needless to say this mode of recovery is not
available from manufacturers
of ROM based systems.
Please keep in mind that the TI-86 is designed for high school kids and is a
robust durable
unit. I have launched my 86 across the boat during a particular rough
passage cracked the cover and
continued doing sight reductions with out a problem. Replacement covers in
a multitude of
colors are available directly from TI and their distributors and an
indestructible padded water proof
box is available for the StarPilot from Starpath if you wish to take better
care of your unit
than I do mine.
Finally, StarPilot updates are available for free over the internet. As new
features are added
to the software customers can easily update their units by simply
downloading the latest
software over the internet. If you feel that a feature is missing in the
StarPilot simply send
us an e-mail. If we feel that the feature is useful to the public in
general we will implement
it and make it available to every one. We have done this for customers
several times
already. For example, The original StarPilot did not implement Sun
Amplitudes or a comprehensive
ETA function. It now does thanks to our users and these features are
available via
download over the internet as version 1.53.
The StarPilot web page has come a long way since its initial release Nov 5.
I invite you
to browse the StarPilot page at
http://www.starpath.com/catalog/tools/1863.htm.
Thanks for our consideration and your e-mailed comments are welcome.
Sincerely,
Luis Soltero, Ph.D.
StarPilot development team
Starpath School of Navigation
|