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READ.ME
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1988-02-03
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SILICON SKY
Larry Adkins
I. Introduction
Silicon Sky is a program which turns your $3,000 IBM computer
into a $3.50 planisphere! Actually, SILICON SKY does a lot
more than your garden variety planisphere. SILICON SKY
displays a quite realistic representation of the celestial
sphere as seen from any latitude on earth for any date and
looking in any direction. The program will display the
location of the sun, moon and planets and will show the
correct phase of the moon. Finally, it identifies the
constellations visible on the screen by marking out their
boundaries. Instructions for use are given in the following
sections.
II. Initialization
SILICON SKY should work on any IBM or IBM compatible
with either a color graphics (CGA) or an enhanced graphics
(EGA) adaptor card. However, you must first initialize the
program. If you have an 8087 math coprocessor type "INIT87"
and return to begin the initialization. If you do not have a
math coprocessor, simply type "INIT" and return. The
initialization program will ask you whether you have an EGA
or CGA graphics card, the name of your default observing site
(up to 30 letters), the latitude of your default observing
site, the time zone of the default observing site, and
whether or not you want to hear "Cricket" sounds. Cricket
sounds occur after sundown when the program is operated in
the PLANETARIUM mode (see below). I would suggest that you
try it with crickets sounds at first. If you find them
annoying simply re-run "INT" or "INIT87" and turn them off.
The disk is released with the following defaults:
Graphics Card: CGA
Default Observing Site: SOUTHERN CALIFORNIA
Default Latitude: 34 degrees
Time Zone: 8 (PST)
Cricket Sounds: Yes
III. Running SILICON SKY
To run SILICON SKY type "GO87" if you have an 8087 chip
or "GO" if you don't, and hit the return. You will see a
screen with the SILICON SKY logo and the words "STAR DATA
LOADING". This will take from 15 seconds to 30 seconds,
depending on whether you are loading from a hard disk or a
floppy (floppies take longer). Note: the program reads
information from the disk from time to time during execution;
therefore, the disk must remain in the drive (or be on a hard
disk) while the program is running.
MODE SELECTION
After the star data has been loaded you will be offered
two options:
1. Stars+Solar System Objects
2. Planetarium
If you select the first option, one screen will be
displayed for the particular date and time you specify. To
see another date and time you will have to enter new data.
The Planetarium mode, on the other hand, will display a
sequence of screens at an interval you select, beginning with
a specified date and time. If you are running the program
for the first time, I would suggest starting with option 1.
LATITUDE SELECTION
The next option is latitude. Two options are available
here, the default location selected during initialization or
some other latitude. Any other latitude on Earth will work
from -90 to +90. If a latitude other than the default has
been selected, you will need to hit the enter key after
typing in the numbers.
DIRECTION OF OBSERVATION AND TIME FUNCTIONS
The next screen prompts for direction of observation -
north, south, east, or west. After one direction has been
selected, you will be prompted for date and time data. If
a latitude other than the default has been selected the
program will prompt you for a time zone from -12 to +12
(Greenwich is 0).
PROGRAM EXECUTION
The sky will now be plotted on the screen. When the
plotting is finished there will be a line at the bottom
representing the horizon and curved lines at the top
representing the top of the celestial sphere. The display is
roughly the field of vision the average person would have
looking at the horizon.
How long this takes will depend on your system. A
"plain vanilla" IBM PC without a math coprocessor will take
about 20 seconds to paint the stars on the screen for most
horizons. It will take an additional 40 seconds or so for
the program to examine all of the stars in the data file.
Thus, after the program begins to run it will be about one
minute before it is ready to accept new instructions.
If you have a math coprocessor or an AT the execution
time reduces to a mere seven seconds!
SCREEN MENU
After the stars have been plotted, a menu will appear at
the bottom of the screen. Any option on the menu can be
accessed simply by pressing the appropriate number. For
example, first option simply removes the menu. Thus,
pressing "1" will result in an unadorned display of the sky.
----THE MENU CAN ALWAYS BE RE-ACCESSED BY PRESSING----
---- THE "ESC" KEY ----
The options and their functions are as follows:
1. REMOVE MENU: Shows sky without menu.
2. OPTIONS: Input new data (latitude, date,
viewpoint.
3. SOLAR DATA: Displays coordinates of sun,
moon and planets along with date and time
data.
4. CONSTELLATIONS: Displays constellations
visible in the CENTRAL AREA of the
screen. The selection of a particular
constellation will plot its boundaries
on the display. [Note: DATA IS AVAILABLE
FOR ONLY 35 CONSTELLATIONS AT PRESENT]
5. PLANETS: Identifies solar system objects.
The sun and moon are labeled. Planets
are identified by a circle drawn around
them.
6. SCROLL: This feature allows you to scroll
around the celestial sphere. Pressing
the appropriate arrow allows you to
scroll 360 degrees around the horizon or
up from the horizon to overhead.
9. RETURN TO DOS: Terminates the program.
IV. Upgrades
This program is being distributed as shareware, and it is
requested that you register your copy by sending $10.00 to the
address below. Payment of the registration fee will entitle
you to the next upgrade. As the program stands now there are
only 35 constellations in the data file. In the next version
this will be extended to include all 88 constellations. I
also plan to include
-- Coordinates
-- Deep Sky Objects
-- Milky Way Boundaries
-- A more detailed manual
Please send registration fee to :
Larry Adkins
17652 Wellington Ave.
Tustin, CA 92680