
NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
RAM vs. ROM for Celestial Calculators
From: Luis Soltero
Date: 2000 Jan 04, 3:10 PM
From: Luis Soltero
Date: 2000 Jan 04, 3:10 PM
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 These products have both been retracted from the SW since I no longer have time to support them.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.i-DEADLINK-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