NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Calculator question
From: Bill Murdoch
Date: 2005 Feb 21, 09:53 EST
From: Bill Murdoch
Date: 2005 Feb 21, 09:53 EST
In a message dated 2/19/05 7:37:25 P.M. Eastern Standard Time,
FrankReedCT@AOL.COM writes:
The most recent TI-89 has something like 3 megabytes of memory. It can take simple programming and also relatively sophisticated code, and they do *symbolic* algebra, trig, and differentiation and integration, too. But no solar power
3 MB is far more memory than is really necessary for a celestial navigation
calculator unless you write software like one of Bill Gates's employees.
Here are the memory requirements used in a TI-82 program that I wrote in the
early 1990's using TI basic.
To input time and convert to a single unit - 468 bytes
To calculate a few time dependent constants - 227 bytes
To input a position - 400 bytes
To calculate almanac data to +/- 0.01 (2 S.D.) accuracy -
Sun - 650 bytes
Moon - 1448 bytes
93 stars - 1682 bytes for data and 632 bytes for the
program
Planets - 411 bytes
plus for each
planet:
Venus - 555 bytes
Mars - 964 bytes
Jupiter - 1451 bytes
Saturn - 1879 bytes
Input sextant and other sight data - 796 bytes
Convert R.A. to GHA - 146 bytes
Reduce the sight - 201 bytes
Display the azimuth and intercept - 191 bytes
The whole program which does almost everything I could think of
except lunars fits in a 28 KB memory.
I too think it would be nice to have solar power and be free of the
batteries.
Bill Murdoch