
      ASTRO
  Benjamin Moody
   ------------

1. What is Astro?

 Astro will be a Flash Application for the TI-83+ which will draw maps of
stars, planets, and satellites.  The user inputs his or her location and
time, and a map of the brightest objects is displayed. Astro will include
a feature to display the names and/or designations of objects, and be able
to zoom in on a certain area of the sky to show more detail.  Astro uses a
large database of fixed stars, star names, and constellations, which composes
most of the Flash ROM space allocated for the application, and will also be
able to use external data files created on a PC from standard format online
catalogs.

2. How to use Astro

 Astro is currently only usable from TI's Flash Debugger.  The program must
be assembled into Intel Hex format (included with this ZIP file) and loaded
into the Debugger as an Application.

 Upon starting Astro, a blank screen will be shown, with a large circle.
This represents the horizon.  North is up, south is down, east is left,
west is right.  The program then commences to plot stars, using your last
session's settings, or the default settings (London, midnight Jan. 1, 2000.)
This may take a while.  You can stop it by pressing ON.  The following
options are currently available from the main screen:

  Y=      Displays Select Objects screen. (Sun, moon, and planets are
            not yet implemented.)

  WINDOW  Displays Set Location screen.  You must know your latitude and
            longitude in degrees and minutes.

  ZOOM    Displays Set Time screen.  Use + and - to change fields.  Time
            zones are counted from GMT and go east.  You should also
            subtract one from your time zone if you are in Daylight Savings
            Time. Date is in American format (mm/dd/yyyy.)

  MODE    Displays Maximum Magnitude screen.  Change using + and -. Stars
            dimmer than this will not be drawn. (Low values speed up the
            drawing a lot!)

  ENTER   Toggles Info Cursor mode.  This will cycle through the names of
            the brightest visible stars using the up and down keys.

 Pressing 2nd [QUIT] from any screen will exit that screen.  After leaving
one of these screens, the sky will be redrawn with the new settings.  As
the screen is drawn, the 3-letter abbreviation of each constellation will
appear as it is drawn.

3. Future Plans

 Astro is not yet complete.  In the future, I plan to add several things:

  - Ability to locate sun and moon
  - Ability to draw planets
  - Zooming in on a section of sky
  - Pointing to objects with the info cursor
    - Identifying lesser objects by designations
    - Details on a star: magnitude, position, coordinates, etc.
    - Details on planets: distance, position
  - Ability to load external files
    - External star databases
    - Asteroids, comets
    - Earth orbit satellites
    - PC side program to create external files

 Please e-mail me if you have any suggestions, comments, questions, etc.

---
Benjamin Moody
benjamin@ecg.mit.edu
 