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S K Y G L O B E
A
Shareware
Product
of
Copyright (c) 1992
3.1
KlassM
SoftWare
Mark A Haney
Congratulations! You are the proud owner of a copy of SkyGlobe 3.1,
the
fun and easy educational astronomy program. SkyGlobe is distributed
as
Shareware to reach the widest possible audience, so let's take care
of the legalities first.
SkyGlobe is copyrighted material. You are granted permission to use
SkyGlobe, and to make as many backup copies for your own purposes as
you want. If you are not a registered user, you are permitted to use
SkyGlobe on a trial basis to see if you find it useful. If you
decide
to keep and use SkyGlobe, your copy should be registered.
You are encouraged to distribute copies of SkyGlobe, subject to the
following conditions:
1) All files, except for the file SKYGLOBE.REG, are
distributed together and unaltered.
2) No charge is made for the software.
(A small fee for media and handling is permissible.)
Anyone who receives a copy of SkyGlobe from you should register
their copy if they decide to keep it and use it.
As I am now a member of the Association of Shareware Professionals,
I have included a copy of their standard Shareware and license
wording, as well as the Ombudsman statement and my support policy,
at the end of this documentation file.
SkyGlobe was originally developed with registered Shareware. Thank
you for supporting the Shareware concept by registering your copy of
S K Y G L O B E ! ! !
_______
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|
(R)
--|
|
|------------------|
____|__ | Association of
| |
|_| Shareware
|__|
o
|
Professionals
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MEMBER
SKYGLOBE
3.1
ORDER
FORM
June 11,
1992
Please use this form to register a copy of SkyGlobe 3.1.
Registration ($20) provides you with the following benefits:
1) A copy of the newest version of SkyGlobe, customized with your
Home Town as the default city, and without the beginning pause
or UNREGISTERED notice.
2) A professionally printed SkyGlobe manual.
3) Automatic notification of new releases and other products.
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Circle Disk Type:
...............................................
5.25"
Circle Default Video Mode: VGA
3.5"
or
EGA
or
CGA
or
Hercules
Please make checks ($20) payable to KlassM SoftWare. This includes
shipping.
For your convenience, I now accept VISA/MasterCard, with a form below.
International customers need pay only $20, which includes airmail
shipping. For those of you without VISA/MasterCard, US dollar checks
drawn on a US bank are safest for me. However, to avoid excessive bank
charges, you might try international money orders or US currency. As a
last resort, I can accept foreign currency, or international checks
denominated in the currency of the issuing bank. Unfortunately, I am
not able to accept Eurocheques. Thank you for your cooperation.
Mail to: KlassM SoftWare
284 142nd AVE
Caledonia, MI 49316-9604
Or call 1 800 968-4994
(US and Canada only)
24 hours, 7 days a week
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Signature:_______________________________________________
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Amount:__________ Expiration:______
Thanks, and I hope you enjoy SkyGlobe!
-3Table of Contents
Welcome Page...................................................1
Order Form.....................................................2
Table of Contents..............................................3
SkyGlobe 3.1 Files.............................................3
Quick Starting Instructions....................................4
About the Reference Card.......................................5
Time and Date Commands.........................................5
Where are We Looking? (SkyGlobe Directions)....................6
Moving Around (Cursor Keys and More)...........................6
What Do We See? (Stars and Zooms)..............................6
The Planets....................................................7
Precession.....................................................8
Finding Planets, Stars, and Constellations.....................9
Printing.......................................................9
Lines and Labels..............................................10
Keeping Track (Screen Displays)...............................11
Mousing Around................................................11
Changing Viewing Locations....................................11
Special Command Modes (SPACE, Home, and End)..................12
Changing Your Environment.....................................13
Memory Requirements...........................................14
Using SkyGlobe with Windows...................................14
The SkyGlobe Projection.......................................14
Saying Goodbye................................................14
Thanks for Your Support!......................................14
SkyGlobe Background...........................................15
SkyGlobe Background continued.................................16
Questions & Answers...........................................17
Questions & Answers continued.................................18
Questions & Answers III.......................................19
SkyGlobe Command List.........................................20
Definition of Shareware.......................................21
Support Policy................................................21
Disclaimer....................................................22
Ombudsman Statement (Help from the ASP).......................22
SkyGlobe 3.1 Files
SKYGLOBE.EXE
stars.
SKY8000.DAT
SKY10000.DAT
SKYGLOBE.DOC
README
SKYGLOBE.ICO
FILE_ID.DIZ
Standalone executable file, containing data for 7000
Data for additional 8000 stars (7001-15000).
Data for additional 10000 stars (15001-25000).
This file.
Program description and late news.
A Windows 3.1 icon for SkyGlobe.
A description file for BBSs and catalogs.
-4Quick
Starting
Instructions
These instructions will enable you to get SkyGlobe up and
running as quickly as possible. Then you can return to the
manual to learn about some of SkyGlobe's advanced features.
SKYGLOBE.EXE is the only file that is absolutely necessary
in order to run SkyGlobe. If you wish to see more than 7000 stars,
you will need the files SKY8000.DAT and SKY10000.DAT as well.
Make certain these files are in the currently active directory,
type SKYGLOBE, and press the Enter key.
If you are a registered user of SkyGlobe, all you need to do
is type GO and press Enter. SkyGlobe will determine your choice of
video adapter and location from the file SKYGLOBE.REG. You can override the video settings from the command line by using a command such
as SKYGLOBE E, for instance, to start SkyGlobe in EGA mode. Other
choices are V for VGA, C for CGA, H for Hercules, M for monochrome,
S for SVGA VESA mode, S2 for SVGA mode 6Ah, S3 for Tseng SVGA
mode 29h, S4 for Trident, and S5 for Paradise chips.
When you type GO and press Enter, you will be quickly presented
with a view of the southern sky for the current time and date. In the
middle of the top of the screen will be a welcome and copyright
message,
which will disappear when you press your first command key. Most of
the
commands in SkyGlobe require only a single keypress.
Let's try a few of the commands. First press 'A' to start the
automatic increment of time. The time, as indicated in the upperlefthand corner of the screen, will begin to change by five minutes.
Press 'Shift-A' to reverse direction, then press 'A' again to stop
the movement. Press 'B' for Brightness a few times and watch more
stars appear. Most actions in SkyGlobe are reversed by using the
Shift key. Press 'Shift-B', and watch the dimmest stars vanish. Try
'Z' and 'Shift-Z' to Zoom in and out.
Want to set a specific time or date? Try 'M', 'H', 'D' and 'T'
for Month, Hour, Day and Time (in minutes). Change the number of
Constellation Lines displayed by pressing 'C'. Use the cursor keys
to change the Viewing Direction and Elevation. And if you ever need
to use your computer for something besides SkyGlobe, press 'Q' to
return to DOS.
I hope this quick introduction has gotten you well started with
SkyGlobe. More detailed descriptions of the commands appear throughout the following pages. Have fun!
-5Time and Date Commands
SkyGlobe provides many ways to change the Time or Date of the
displayed sky view. You can change the Time forward or backward by a
minute or an hour. The Date can be changed forward or backward by a
day, a month, a year, a century, or a millenium. Except for tiny
changes which are corrected for by leap years, only the planets
generally change from year to year. Over great time spans, precession, the wobbling of the Earth's axis, becomes evident.
Use the table below to help you remember:
1
1
1
1
1
1
1
Minute
Hour
Day
Month (30 days)
Year
Century
MilleniUm
Forward
Press 'T'
'H'
'D'
'M'
'Y'
'J'
'U'
Backward
Press 'Shift-T'
'Shift-H'
'Shift-D'
'Shift-M'
'Shift-Y'
'Shift-J'
'Shift-U'
One of SkyGlobe's most useful features is the Auto-Increment
mode. This gives you the ability to simulate the passage of time on
your computer. To enter or exit this mode, press 'A'. The sky view
will begin to change in a manner that depends on the Auto-Increment
parameters. Use 'Alt-A' to change the increment type from Time to
Date and back. Use 'Shift-A' to change the direction of increment
from Forward to Backward and back. You can also change the speed of
increment. Press '>' to increase the speed, and '<' to slow back down.
Only the active increment type, either Time or Date, is affected by
the '>' and '<' keys.
There are two ways to quickly activate some special AutoIncrement modes. Press 'R' to enter (or disable) Real-Time mode.
This will synchronize the Time and Date to the system clock. You
still have control over all commands except those related to Time
and Date. Press 'Shift-R', and the Increment speed will be set to
one Sidereal day, or about 1436 minutes. This has the effect of
seeming to freeze the star and constellation display, while allowing
the planets to continue their progress along the ecliptic. This is
useful for learning about retrograde motion, as well as teaching
something about the relative speeds of motions of the planets.
If you would like to see what the sky will look like in the
far future, or are more interested in the ancient past, the 'J',
'Shift-J', 'U', and 'Shift-U' keys will Jump the Date by a century
or change it by a milleniUm. This will give you the chance to learn
about the wobbling of the Earth's axis called precession, which is
described in greater detail later.
-6Where
Are
We
Looking?
Now let's learn about how SkyGlobe interprets directions. The
program assumes you are standing outside and that your eyes are
facing the same direction your feet are pointing. This is the View
Direction. The display shows this direction in degrees, ranging from
0 for due north, through 180 degrees for due south, to 350 degrees
for 10 degrees west of north. The View Direction is also indicated
by abbreviations in the parameter display, as well as along the
Horizon line by initials.
The View Elevation ranges from 0 degrees to 90. The Horizon appears as a straight line at the 0 degree setting. It might help to
imagine that you are extremely short for this one, so that the ground
covers the lower half of your eyes, but is transparent. The 90 degree
setting is like looking straight overhead at the Zenith.
Moving
Around
SkyGlobe provides many convenient methods for rapidly changing
the sky view. The up and down arrow keys change the View Elevation
by 5 degrees. The right and left arrow keys work with the View
Direction. When the View Elevation is near the Horizon these keys
work about as you expect, but nearer to the Zenith they rotate the
view more than they move it. This is correct when you remember that
the View Direction stands for where your feet are pointing. PgUp and
PgDn change Elevation in multiple jumps. Use Alt or Ctrl with the
arrow keys to change the direction in smaller amounts. Finally, you
can
change the View Direction instantly to compass points by pressing
'N', 'S', 'E', or 'W'.
What
Do
We
See?
Lots and lots of stars! You can change the number of stars
displayed by pressing 'B' for Brightness to increase the number, or
'Shift-B' to decrease it. The number of stars added or deleted from
the display depends on the number currently displayed. After the
number of stars currently displayed is an indication of the limiting
magnitude this number represents. This is the magnitude of the dimmest
star displayed.
SkyGlobe allows you to adjust the magnification of your sky
view. At a nominal magnification of 1, with the Inflated projection
chosen, (this is the program default) half of the celestial sphere
is visible. Since the eye can focus on far less area than this, a
certain amount of distortion is evident at low magnifications. Still,
you can use these views to quickly find areas of interest. The center
of the screen is always the most accurate portion. Use 'Z' to increase
the magnification and 'Shift-Z' to decrease it. In common with many
SkyGlobe commands, as described below, you can use 'Alt-Z' and 'CtrlZ'
for smaller increments, and 'Home-Z' and 'End-Z' to quickly maximize
or minimize the Zoom index.
-7The
Planets
You can use SkyGlobe to learn something about the way the
planets move around the Sun. The very word 'Planet' is derived from
the Greek word for wanderer. The ancients, who spent more time outof-doors than we do, noticed that a few bright 'stars' seemed to
move against the 'fixed' background of the rest of the heavens.
(Here I mean fixed with respect to each other; they were acquainted
with the slow progression from one season to the next of the whole
'sphere'.) They soon worked out the repetitive patterns the different 'stars' followed. We will learn how to simulate this motion
shortly, but first we need to talk about some SkyGlobe features
that are relevant.
Although the stars don't really change much from one year to
the next, the planets do. Notice the year displayed on the Date
display in the upper left-hand corner. If this Time and Date are
not displayed, press F2 to turn this display on. Use 'Y' or 'Sh-Y'
to increase or decrease the year. You can use F3 to turn on the
planet display, and to turn on planet labels. EGA/VGA color users
see the planets in more or less appropriate colors. You may need
to change the Time or Date to see your favorite planet.
Now that we have seen the planets, let's see how they move.
Change the Viewing Direction to South and the Time to 12:00 noon.
Turn off Daylight Time by pressing 'V'. Set Auto-Increment Type to
Date by pressing 'Alt-A' if needed. Now press 'A' and watch the show.
If you want to see how the planets stick near the ecliptic, make sure
its display is turned on, by pressing F6 if needed. Since your
location
may not fall exactly on the Standard Time meridian, the Sun may not be
due South for you at Civil noon. Also notice how it wanders from side
to side throughout the year, as the Earth speeds and slows down along
its slightly elliptical orbit.
Notice how Mercury and Venus stay close to the Sun. Mars has
positively weird behavior, since it is outside the Earth's orbit, but
relatively close by. It also has an eccentric orbit. The other outside
planets drift more slowly against the background of the stars. You
may see more clearly how the moon goes through its phases, being always in New Moon phase when near the Sun. Move to Midnight, and the
Moon will be in Full phase when it shows up in the South. Since the
orbit of the Moon is inclined at about 5 degrees to the ecliptic, it
wanders above and below it each month. This motion, which rotates
through an 18 year cycle, accounts for the periodicity of eclipses.
SkyGlobe 3.1 uses calculated planetary positions to allow for planet
display without the need for data tables. For instance, take a look
at the solar eclipse of July 11, 1991. Slowly step through the hours,
and watch how the moon gradually overtakes the Sun.
Another interesting way to watch the motion of the planets is
with
the Sidereal Time mode of the Auto-Increment feature. Find a direction
and a time and date that contain some planets, and press 'Shift-R'.
The
time will begin incrementing by 23 hours 56 minutes, or one sidereal
day. The planets, especially the Sun, Moon, and inner planets, will
begin to drift against the unmoving background of the stars.
-8Precession
One pattern that is difficult to explain with words and books,
but
which lends itself perfectly to the animation features of SkyGlobe, is
the 25,800 year wobble of the Earth's axis called precession. We think
of the North Star as constant and unchanging--there's even a
Shakespeare
quote to that effect!--but in fact it is a lucky accident for us that
Polaris, a 2nd magnitude star, is so very close to the north celestial
pole. (SkyGlobe trivia: Polaris used to be the defining star of the
magnitude scale until it was discovered to be slightly variable. It
was set equal to magnitude 2.0 exactly, and all other brightnesses
were
compared to it using a logarithmic scale.) Our North Star will
gradually
come even closer than its current three-quarters of degree to the
actual
pole until about 2100, when it will start to draw away. Stargazers of
the future will use stars such as Errai, Alderamin, Deneb, Delta
Cygni,
Vega, Thuban, and Kochab as their North Stars, as well as some lesserknown lights. Some of these are better fits than others. The pattern
will then begin to repeat in about 27900AD, when Polaris will again be
very close to the pole. The same sequence extends into the past.
But enough of this exposition; a SkyGlobe view is worth a
thousand
words! First we need to find a view where the celestial north pole is
easy to see. Press 'N' to instantly choose a viewing direction of
North,
and use the Zoom features and up or down arrows to select a view which
comfortably displays the coming together of the RA-Dec lines at the
pole.
You could also try 'F' and use the menus to find Polaris. You may find
it helpful to change your latitude with 'Alt-N' or 'Alt-S' to an even
number, so the pole falls on top of a hash mark. One nice option is to
change your location to the North Pole and look toward the Zenith.
So far, so good, we can look at the north celestial pole. Big
Deal,
you say? Press the Space bar to enter Turbo mode, and then select 'U'
to continually increment the Date by one milleniUm. The algorithm that
precesses the view gets a little slow for faraway dates, especially
without a math coprecessor, so we want the biggest changes we can get.
Polaris and the RA-Dec lines for the current epoch will start to spin
off to the side, and the new North Stars will come in from the other
side. If you start this with the mouse on top of the old pole it will
help to show us the changes happening. The RA-Dec coords displayed
will
stay fairly near to 90 degrees Declination, with some error creeping
in,
while Polaris gets further and further away. If you move the mouse
cursor
on top of Polaris again--you may want to turn off Turbo for this--you
will notice it is no longer near the new celestial pole. You can also
use the 'J' key to Jump by a century instead of a milleniUm, and use
the Shift keys to go backwards.
We are limited to about one cycle in each direction, mostly since
it gets pretty slow going toward the endpoints. The planets are still
displayed throughout this range, but I wouldn't plan a trip to them
based on these coordinates. They are approximately correct for as far
back and forward as I have data. I have followed the astronomical convention of using the Julian calendar backward indefinitely, even
though
no one was using our month names tens of thousands years ago.
-9Finding
Planets, Stars,
And
Constellations
Let's say you wish to find a planet, or perhaps your favorite
constellation. Press 'F' to access the Find menu. Use the cursor keys
to navigate the menus, using PgDn and PgUp to choose other pages for
other types of Objects. The display will be re-centered at the chosen
object, if it is visible from your latitude. If necessary, the time
will
be incremented until the object is above the horizon. The next time
you use the menus, the last chosen object will be under the menu
cursor.
Rather than going through the menus, you can quickly identify
many
stars by placing the mouse cursor over them. If they are among the
brightest 300 stars, their name will appear in the lower left-hand
corner, if the mouse is on. If you press the left mouse button, the
display will re-center at the mouse cursor. Press the right button
to return the center of the display to old mouse position. The action
of the mouse cursor will appear somewhat erratic during Auto-Increment
modes, since its position is only updated once per display in these
modes. You may prefer not to move it, or to turn it off with F11 or
Alt-F5.
I would like to say a few words here about nomenclature. The
names of the constellations are well standardized. Many of the
strange names in the southern sky are Latinized names of scientific
implements, since these constellations were named, (by the Western
world, that is), in the beginning of the Industrial Age. Most of the
northern constellation names go back much further. We use the
genitive,
or possessive, form of the constellation name to denote star names.
For example, Alpha Centauri means the first star of Centaurus. The
stars were generally enumerated in order of brightness. Since star
brightnesses change with time, this correlation is not always exact.
Many stars also have popular names, which are not standardized nearly
as well as constellations. Most of the names are Arabic in origin.
This reflects the fact that the Arabic world maintained and developed
astronomical knowledge while Europe was struggling through the Dark
Ages. You may want to take my lists with a grain of salt. Fifty-seven
stars have been chosen for celestial navigation purposes by the
various
authorities, and labels for these stars appear in a different color
in EGA and VGA color modes.
Printing
A snapshot of the screen may be printed with the use of the 'P'
command. You will be prompted to choose a printer type, and the output
will be directed to either LPT1 or LPT2, depending on the setting
chosen
with Alt-F7. No matter your video type, a display will be created in
VGA
resolution for dot-matrix printing, or SVGA resolution for HPcompatible
laser printing.
-10Lines
And
Labels
One of the most useful features of
quickly and easily change the lines and
and minds make sense of the vastness of
helpful to the novice just learning the
SkyGlobe is its ability to
labels that help our eyes
the sky. This can be very
stars.
Use the 'C' key to increase the number of Constellation Lines
displayed. As always, use the Shift key to reduce the number of lines.
The Constellation Lines have been grouped by importance, with some
constellations having several classes of lines, such as the extra
lines
that change the Big Dipper into Ursa Major, the Great Bear. You can
instantly turn on or off these lines with F10, which is a good way to
learn the star patterns underneath the constellations.
There are also several choices for labelling the constellations.
Use F9 to roll through No labels-abbreviations-Small font full namesLarge font full names-No labels again.
The 1000 brightest stars can be labelled with numbers that represent their brightness standing, and the three hundred brightest stars
can be labelled with their names. Use F8 to roll through No LabelsNumbers-Small font names-Large font names-No Labels again. To change
the number of stars to label, use F11 or Shift-F11. For those of you
without this key, try Shift-F8, Home-F8, or End-F8.
The F5 command rolls through the Horizon Line, Zenith cross, and
Hash-Mark displays.
The F6 command toggles the Ecliptic Line Display.
Two levels of display are supported for RA-Dec grid lines, which
can be controlled with the F7 key. These lines act somewhat like latitude and longitude lines on the globe of the Earth. Try looking due
North in Auto mode with the lines on, and watch the celestial sphere
rotate. This helps show how the Pole Star appears almost motionless.
The Messier Objects--a list of 110 Deep Sky Objects compiled by
Charles Messier--can be labelled with descriptive icons or the letter
plus the appropriate number. The different types of objects are: open
clusters, globular clusters, nebulas, spiral galaxies, and elliptical
galaxies, which should be self-explanatory when you see them.
A beautiful representation of the Milky Way can be controlled
with
the 'K' key. This key will roll through: No display-Outlines only-Gray
shaded regions-Blue shaded regions. You can adjust the brightness of
the
shaded regions (VGA and SVGA only) with 'Alt-K' for the inner region
and
'Ctrl-K' for the outer.
You can place a frame around the rectangular screen display or
the round SkyGlobe with the 'O' command. The choices roll through No
Display- Rectangular frame-Round frame-Rectangular and Round framesOff.
You can roll through all fifteen displayable colors for these lines
with
'Shift-O'.
-11Keeping Track
SkyGlobe has two handy on-screen displays to help the user. The
left-hand display will help you keep track of settings such as the
Zoom
Index, and will remind you of the Viewing Location. By pressing F2 you
can see the Auto-Increment parameters, the Print parameters and other
miscellaneous information. This display can be blanked by pressing F2
yet again, or use Shift-F2 to peel off one screen at a time.
A Help screen appears on the right-hand side of the screen. This
display will remind you of the single-key commands of SkyGlobe. Press
F1, and the function key assignments appear (on non-CGA machines). One
more F1, and the list of alternate function keys shows up. Press F1
again to turn off the Help display.
Mousing Around
SkyGlobe displays some handy information about the position of
the
mouse cursor. The RA-Dec coordinates of the mouse cursor, along with
the
name of any object underneath it, will be displayed in the lower lefthand corner of the screen. If the object is a star, its magnitude is
displayed. The height and direction of the cursor, which are called
the Altitude and Azimuth, are also displayed. If you wish to re-center
the display at the spot of the mouse cursor, press the button. As long
as the chosen spot is visible from your location at some time, the
spot
under the mouse cursor will become the new center of the screen.
Pressing
the right mouse button will return the screen to the position before
the
left button was pressed. You can control the position display with F11
or Alt-F5.
Changing
Viewing
Locations
One of the most popular pastimes for new astronomers is seeing
what the sky looks like from other places. Perhaps you're thinking
of moving, and want to make sure the stars will still be interesting
to view from your prospective new home. (They will be!) Press 'L' to
pull up a menu of locations from which to choose. Your current view
will be left untouched at the bottom of the screen. Use the cursor
keys to select any location you wish. Once you make your new choice
you will return to the program with all your other parameters just
the way you left them. Since SkyGlobe 3.1 now has over 230 locations,
there are two pages of locations to choose from. Use the 'End' key to
quickly go to the spot that changes between pages.
You can also use 'Home-L', 'End-L', 'Alt-L', and 'Ctrl-L' to
choose locations from the menu without actually using it. The first
two select the first location on the menu, normally Caledonia MI, and
the Equator. The last two move either one down or one up on the menu.
If you wish to move a small amount in a compass direction, try
'Alt-N', 'Alt-S', 'Alt-E' or 'Alt-W'. Then you can change locations
without ever taking your eyes off the current display. The east and
west moves simply have the effect of changing the local time by 1
minute. The north-south changes are 1/4 degree, about 17 miles.
-12Special Command Modes
The SPACE bar, Home and End keys, and Alt and Ctrl keys, have
special meaning in V3.1. These special command modes can be very
useful
to make using SkyGlobe even easier. Try them, you'll like them!
The SPACE bar activates Turbo mode, which takes the next keypress
and continually feeds it into the program, until the SPACE bar is
pressed
again. This feature is particularly useful with Zoom, direction, and
Time
and Date commands. Try it with 'J' or 'U' while facing North to see a
great demonstration of precession.
The Home and End keys, for many commands, take the next keypress,
and either minimize or maximize the program parameter altered by that
key.
These are helpful for Zoom and Brightness, and are convenient ways to
set
the Time and Date to even numbers, such as midnight or Jan 1.
The Alt and Ctrl keys often work as smaller positive and negative
increments for the command with which they are used. Once again, Zoom
and direction commands work well with these keys.
Let's try an example that illustrates these features. First,
press
Home, followed by 'Z', to reset the Zoom Index to 1. You will have
noticed that you were prompted to enter the command to be used with
the Home feature. Now, press the SPACE bar. You will be prompted to
enter the Turbo key. Let's use the Alt feature here. Hold down the Alt
key, and press 'Z'. The display will slowly begin to expand, and a
message on the bottom of the screen will remind you to press the SPACE
bar when you wish to exit Turbo mode. Now try it for yourself! TurboAlt-arrow is a good choice, although you might want to try Ctrl-arrow
if you have trouble with the Alt-key combinations.
Using the Alt-key in conjunction with the function keys can be
used to control some of the more obscure parameters in SkyGlobe 3.1.
Alt-F1
Alt-F2
Alt-F3
Alt-F4
Alt-F5
Alt-F6
reduces the display to stars and constellation lines only.
reduces the display to stars only.
gradually changes the background color from black to blue.
enables Twilight Mode, which artificially brightens the
background when the Sun or Moon is above the horizon.
turns off the mouse position display, independently of the
F2 Parameter Index. This makes mouse centering impossible.
toggles the Precession flag. With the current range of only
200 years, this is not all that valuable, but it does work.
Alt-F7
Alt-F8
toggles the printer port between LPT1 and LPT2.
controls whether line feeds are added to carriage returns
while printing.
Alt-F10 controls the Aspect Ratio, useful for laptops and SVGAs.
The TAB key is used for an interesting SkyGlobe feature. It will
find the next sunrise or sunset, depending on the current situation.
This feature occasionally stutters if used continually, and please
don't tempt fate by using it too close to the poles, as your system
will probably lock up.
-13Changing Your Environment
SkyGlobe 3.1 adds the capability to customize many program
settings.
In VGA and SVGA color modes, you can brighten or dim the RA-Dec line
and
text colors with '+' and '-', and this bias can be saved in the .CF0
file
(explained below). The text color can be changed with '/', and you can
toggle between normal and reversed text with '.'. The Background color
can be changed from black through several shades of blue with Alt-F3.
You
can select a twilight mode with Alt-F4. This will artificially
brighten
the background color when either the Sun or the Moon is visible. The
type
of Time display, either AM/PM or 24-hour, can be toggled with '='.
Use of the number keys allows for the saving of current program
settings. Up to 10 different settings may be saved, one of which will
be used as the new program default. These keys will create the file
SKYGLOBE.CF#, where # is a digit 0 through 9. When SkyGlobe is
started,
it looks for the .CF0 file to get its initial settings. If you would
rather use the default settings, delete or REName this file. If you
want to use one of the other files, just use SKYGLOBE #, such as
SKYGLOBE 4 to use SKYGLOBE.CF4. This scheme allows for the use of
batch files, such as ECLIPSE.BAT=SKYGLOBE 1, where SKYGLOBE.CF1 has
been set up for July 11, 1991. These parameters can be mixed with
video
choices, as long as you separate the parameters with spaces. You can
load these .CF# files from directly within the program with the
Shifted
number keys.
If you are a registered user, the file SKYGLOBE.REG specifies up
to three custom locations. (For unregistered users, you can use configuration files to use a nearby location as a default, without the
need to go through the Location menu.) These custom locations will
occupy the top three spots in the Location menu. When your order was
filled, your Home Town was placed in the top spot, while Caledonia and
Roscommon occupy the next two. If you move, or you wish to change the
second and third cities, you may use any text editor to do so. But
PLEASE BE CAREFUL! Before you make any changes, you should make a copy
of the file. Then make certain you don't change the lengths of any
field or the whole file. The location name, latitude, and longitude
fields should be self-explanatory. The first three characters refer
to North-South, West-East, and Daylight Time, respectively. Use 'N'
or 'S', 'W' or 'E', and 'Y' or 'N' to specify the hemispheres, and
whether Daylight Time is used. The next two characters refer to the
time zone used. This number refers to the number of half-hours around
from the Greenwich meridian the standard meridian for the time zone
is.
Use 10 for Eastern Time, 12 for Central, 14 for Mountain, and 16 for
Pacific. European continental time is 46, not -2 or anything. You can
also use this method to specify a location if you are traveling, such
as an ocean voyage.
SKYGLOBE.REG also allows for the specification of either DOT or
LAS
default printer types, and either HER, CGA, EGA, or VGA default video
types. If your order didn't say, I let the program make its best
guess.
This can be overridden on the command line, as shown on page 4, or you
can edit the appropriate line in the .REG file.
-14Memory Requirements
This version of SkyGlobe requires about 440K of free memory to
to run in full-color mode. If SkyGlobe detects a low-memory condition,
its
first remedy is to try to run without loading SKY10000.DAT, then
without
SKY8000.DAT. If these remedies are insufficient to run in full-color
mode, SkyGlobe attempts to run in monochrome mode, which only requires
about 250K of free memory. If possible, SKY8000.DAT and SKY10000.DAT
are then loaded, since they require less memory than full color. I am
working on an 8-color mode (as opposed to the current 16 colors) which
will save 64K. This will lower the color memory requirement to about
366K,
which should be well within the range of most users.
Using SkyGlobe with Windows
SkyGlobe will work just fine under Windows in full-screen mode.
I have included a SKYGLOBE.ICO Windows icon. To install SkyGlobe and
use this icon, follow this procedure: Choose which Group you would to
install SkyGlobe in, and make it the active Group. Choose New from the
File menu and click OK to add a Program Item. Use the Browse feature
to
find the directory which contains the SKYGLOBE.EXE file. To use the
icon, select Properties, then Change Icon. You will have to type in
the name SKYGLOBE.ICO, then click on OK.
The SkyGlobe Projection
SkyGlobe 3.1 offers two projections for displaying the sky. The
original SkyGlobe projection is a simple orthographic one. The newer
projection, which is the program default, is a modified version of an
orthographic view, which stretches (or Inflates) the display to
preserve
realistic shapes near the edges. Use 'I' to toggle between the two.
Saying Goodbye
Finally, press 'Q' or ESC to return to DOS.
Thanks
For
Your
Support!
I hope you enjoy SkyGlobe! Since SkyGlobe is Shareware, you
are encouraged to please pass it on to anyone who may find it
interesting. Registered Users will automatically hear about future
updates. Any suggestions you may have will be greatly appreciated.
(Some future plans can be found on page 16.) I can be reached on
CompuServe as 76207,3377, or in care of the address on the order form.
Thanks, and have fun learning about the stars!
-15-
SkyGlobe and the Stars - Some Background Information
Why do we see different stars at different times? The Earth makes
one complete rotation every day. If there were no Sun we could see
that
the stars appear to make one complete revolution at the same time. The
North Star, Polaris (#51), is almost directly above the North Pole on
the Earth's axis of rotation. So the stars near the North Star (about
halfway up the northern sky in mid-northern latitudes) make tiny
little
circles every day. Farther away from the North Star the stars and the
constellations they form wheel across the sky in huge arcs before they
disappear below the horizon.
Why do we see different stars at different dates? Imagine
midnight
in April. The Sun is behind the Earth, and you are facing away from it
if you face due south. Now imagine midnight in October, six months
later.
You are still facing away from the Sun. But because the Earth has
moved
halfway around the Sun in its yearly orbit, you are looking in exactly
the opposite direction to the one you were in April. So different
stars
are visible at midnight, and the ones near the North Star have made
half
a revolution. If there were no Sun, you could see that at noon the
October
sky is the same as the midnight sky in April.
Before Standard Time Zones were instituted, the Sun was due south
at noon everywhere. That was what noon meant. Now that is true only if
you happen to live near the center of the time zone. If you live in
Michigan, the Sun is due south around 12:30 or so. In New York City,
which near the center line for the same time zone, the Sun reaches due
south a few minutes before noon, over a half hour earlier than in
Michigan. The Sun reaches due south somewhat later in Chicago than
in Michigan, but because Chicago is in the Central time zone this
occurs before 12:00PM. This has to be allowed for to make the display
correct, and is unique to each location. Daylight Saving Time is
handled
in a similar manner, and is indicated on the Time Display by the
letter
D before the time if Daylight Time is in use.
The sky can be viewed as a sphere with the Earth at the center,
and
the stars as fixed points on the sphere. Any attempt to represent this
3-dimensional space on a 2-dimensional surface inevitably introduces
some distortion. SkyGlobe uses a unique projection that can be
calculated
very rapidly and provides quite accurate rendering of shapes as they
appear in the sky, even near the edge of the display. The old orthographic projection used in earlier versions of SkyGlobe (and still
available through the use of the 'I' command) had fairly severe distortions near the edges, and was only slightly faster.
-16Background Continued
Another issue that must be dealt with is double stars. Perhaps as
many as half of all stars are actually multiple star systems. The
naked
eye frequently interprets two dim stars close together as one brighter
star. Many 'stars' that serve as end-points on constellation lines fit
into this category. If these stars were left dim and separate they
would
appear 'invisible' at low brightnesses and make constellation shapes
unrecognizable. At higher brightnesses and low magnifications these
stars
would be plotted on top of one another as points, still artificially
dim.
The solution is to combine magnitudes for these stars. The ordering of
stars in SkyGlobe reflects this combination, so at medium brightnesses
and magnifications the display is as realistic as possible. The dimmer
star is retained at its actual brightness, so at very high
magnifications
and brightnesses you will see one artificially bright star and one
correct
dim star.
SkyGlobe contains coordinates for 7000 stars in the file
SKYGLOBE.EXE.
This represents all the stars visible to the naked eye. These
coordinates
were obtained from Sky Catalogue 2000.0 with permission from the
publisher,
Sky Publishing Corp. This permission is gratefully appreciated. The
files
SKY8000.DAT and SKY10000.DAT contain another 8000 and 10000 stars.
SkyGlobe was programmed mostly in assembly language for maximum
speed.
Since there is necessarily a tradeoff between speed and accuracy, the
precision of the star coordinates was carefully matched to the
resolution
of the graphics display and the projection algorithm chosen.
Of course, no program is perfect. Any suggestions or bug reports
would be greatly appreciated, and if you have any problems getting
this
version of SkyGlobe up and running on your system, don't hesitate to
contact me. I can be reached at the address on the order form, or on
CompuServe at 76207,3377.
I have many plans for future enhancements to SkyGlobe. Actually,
many of these are already completed, such as constellation boundary
lines, and the ability to click on constellations and turn their lines
on and off individually. (No, not each line, just each constellation!)
As I was preparing for this update, which had a June 15 deadline for
the ASP mailing, I ran out of code space. That meant I had to make
some hard decisions, and some really neat but large features were
forced out this time, while some smaller ones were retained. Other
future plans include higher-resolution printing, more efficient use
of memory, expanded help, more stars, more DSOs, and an 'Observation
Alert' feature. I have also been working on a display of our Neighbor
Stars, tentatively called the Crystal Sphere, which looks pretty neat
already. This may be a standalone product someday, but it is more
likely to be an adjunct to SkyGlobe.
-17Questions and Answers
Why won't SkyGlobe run in color on my system?
There are two different answers to this question. Many people who
have color CGA systems expect SkyGlobe to run in color on their
systems.
Unfortunately, the resolution of CGA color mode is only 320x200, which
is
insufficient to produce the high quality display necessary for
SkyGlobe.
Those of you with EGA or better displays may be equally dismayed
if SkyGlobe comes up in monochrome mode on your system. This is due to
a lack of available memory, and you should notice a message to that
effect when SkyGlobe is started. (You can force monochrome mode with
SKYGLOBE M.) A full explanation of what is happening appears on page
14 of this document. One other possibility is that SkyGlobe may be
using the value in your SKYGLOBE.REG file to start up in CGA mode,
even though you now have a better display available. To change this,
either change your SKYGLOBE.REG file, using the instructions on page
13, or start SkyGlobe with SKYGLOBE V.
How can I speed up SkyGlobe?
There are really several answers to this question. SkyGlobe
always
does what you ask it to do as fast as it can. (We think it's pretty
fast!) The trick is to ask it to do things in a way that seems faster.
The first method involves asking SkyGlobe to do less work. Try
turning off everything you can do without, especially the Milky Way,
planets, and horizon line. Other possibilities: ecliptic, right
ascension and declination lines, extra constellation lines, and
dim stars. In addition, determining the location of the mouse
cursor tends to be a slow operation, so you may want to turn it
off by using F11 or Alt-F5.
The second method applies only to Auto-Increment mode. SkyGlobe
starts off changing the view five minutes at a time. You can increase
this rate by pressing '>'. Another way is to change the increment type
to Date mode by pressing 'Alt-A', Then increase the Date increment
rate
by pressing '>'.
Finally, you can use several of the helpful keyboard shortcuts
available in SkyGlobe to create just the view you desire. My personal
favorite is Turbo mode, which is entered by pressing the SPACE bar.
When you enter Turbo mode, the next key you press becomes the Turbo
command. This means it will be continually fed into the program, just
as if you were pressing it yourself. You can use this to zoom in with
Z or Alt-Z, and you can sit back and watch it happen, instead of
deciding
how many Zs to hit. When you are satisfied, just press the SPACE bar
again.
Try this with Alt-arrow keys, or Ctrl-arrows, since not all keyboards
are
the same. It's also convenient for Turbo-H or Turbo-M, if you really
want
to get to a Time or Date in a hurry.
The Home and End keys can save a lot of time as well. They
generally
go immediately to the minimum or maximum values of a command or
feature.
With Time or Date commands, this is the quickest way to go to midnight
or
-18Q & A continued
noon, or the first or 15th of the month, or January or July. End-B is
by
far the quickest way to turn on all the stars. Home-Z is the quickest
way
to return to the minimum Zoom, and you can follow it with SPACE-Z to
get
to some moderate value.
For changing direction quickly, you can't beat the N, S, E, and W
direction commands. PgUp and PgDn can change the View Elevation faster
than single arrow commands. Use the mouse button to quickly re-center
the
display at the position of the mouse cursor. And you can use Find to
center
the display at a particular object, instead of figuring out how to get
there with the right combination of arrow keys.
Why can't I get the new SkyGlobe to run from my hard drive?
If you have both the old SKYGLOBE.COM and the new SKYGLOBE.EXE in
the same sub-directory, you will not be able to run the new program.
You
either need to DELete SKYGLOBE.COM, or REName SKYGLOBE.COM SKY25.COM.
Why does the screen go blank when I try to start SkyGlobe?
If you attempt to start SkyGlobe in a video mode that is not
supported by your system, the usual result is a blank screen, perhaps
with the DOS prompt changing color. You will usually be able to get
back to DOS by pressing 'Q'. If you are attempting to use SVGA, you
may want to try SKYGLOBE S2, S3, S4, or S5 instead of SKYGLOBE S. The
normal mode used for SVGA is the VESA standard, and you may need to
load the VESA driver that came with your video card before starting
SkyGlobe. The S2 is an older commonly used mode (6Ah), S3 is for Tseng
chips, S4 is for Trident, and S5 is for Paradise. If you know you have
SVGA capability, but none of these will work for you, please contact
Klassm Software for further assistance. Otherwise, try working your
way up from CGA to EGA to VGA mode, to see if the program will work
in one of these modes, with SKYGLOBE C, SKYGLOBE E, and SKYGLOBE V.
For a Hercules monochrome system, try SKYGLOBE H.
Why does the display jump sometimes?
This is usually due to Daylight Time becoming active or
inactive.
SkyGlobe currently uses US average US dates for Daylight Time (Summer
Time) in Northern Hemisphere locations, and common Australian dates
for
the Southern Hemisphere. Policies vary from year to year and place to
place. Although it was Benjamin Franklin who first proposed Daylight
Time, it wasn't widely used in the US until WWI in 1918. Therefore,
even for locations that customarily use Daylight Time today, I
normally
deactivate it before that date. At any time, you can force Daylight
Time
with Shift-V. If it is active when you don't want it, press V to deactivate it.
One other time the display jumps is during the changeover from
the Julian to the Gregorian calendar. This took place at many
different
times in different countries, but SkyGlobe assumes that Oct 4, 1582,
was
followed by Oct 15, 1582.
-19Questions & Answers III
Is there a version of SkyGlobe for the Macintosh?
Since so much of SkyGlobe depends on assembly language
programming,
porting the program to the Macintosh would be a major undertaking. Now
that V3.1 has some of the front end programmed in C, one small step
for
SkyGlobe has been taken in the portable code direction, but there are
no
immediate plans at the moment to work on a Macintosh version. There
are
still too many improvements to be made in the DOS world!
Why does SkyGlobe always start with the same date, instead of today?
You must have a Configuration file setup for a particular time
and
date. Many people wish to save their own default settings for zoom,
brightness, etc., but still wish to have SkyGlobe come up with the
system
time and date. To do this, press '0' to create a new default
configuration,
but make sure to press '1' when asked whether to use current or system
time. If you wish to save a setup for an eclipse or a birthday, use 19
as the Configuration file number, press '0' to use Current as the
time,
and use SKYGLOBE 1 (or whatever) to start up with the appropriate
settings.
What about Caps Lock?
SkyGlobe attempts to ignore Caps Lock, so the Shift Commands will
operate properly. If for some reason you find some commands behaving
backwards, perhaps SkyGlobe is having trouble identifying the Caps
Lock
state, so you may want to turn it off.
Why does the time change sometimes when I Find an object?
If the desired object is not currently above the horizon, but it
will
be sometime during the next 24 hours, the time will be incremented
until
the object just clears the horizon. It is possible that you are more
interested in the date that an object will appear over the horizon for
a given time. You might be able to use Sidereal Time mode to your
advantage here, but there is currently no way to select for date instead of
time, or to defeat the time increment feature.
Why won't SkyGlobe print properly on my system?
When you press 'P', you will be prompted to choose between 9-pin
dot
matrix, 24-pin dot matrix, and laser printers. The printout will be
directed to the printer port you have chosen, LPT1 if you didn't
change
it, and will insert line feeds for the dot matrix printers. You can
change
the port with Alt-F7, and the line feed state with Alt-F8. The aspect
ratio of the printout should be correct, but the current printout may
not quite fill the page. Printing will continue to be improved in
future
releases of SkyGlobe.
-20SkyGlobe Command List
A-Auto-Increment Mode
commands
B-Brightness
C-Constellation Lines
D-Date
E-East
F-Find Object
H-Hour
I-Inflate
J-Jump Year
K-MilKy Way
L-Location
M-Month
N-North
O-Outline
P-Print
Q-Quit
R-Real-Time
S-South
T-Time (Minute)
U-MilleniUm
V-Daylight Time
W-West
X-Mirror Image
Y-Year
Z-Zoom
Space->Turbo mode
Left Mouse Button
Right Mouse Button
TAB
to reverse operation of the
command.
Use Home with many commands
to minimize the associated
feature of the command.
Use End with many commands
to maximize the associated
feature of the command.
Use Alt with many commands
to increment the associated
feature a small positive
amount.
Use Ctrl with many commands
to increment the associated
feature a small negative
amount.
Continually feeds the next keypress to SkyGlobe.
ReCenter Display at Mouse Cursor position.
ReCenter Display at old Mouse Cursor position.
F1-Help
F2-Parameter Display
F3-Planets
F4-Messier Objects
F5-Horizon
F6-Ecliptic
F7-RA-Dec Lines
F8-Star Labels (type)
F9-Constellation Labels
F10-Constellation Lines
F11-Mouse Display
F12-Star Labels (number)
0-9
Shift 0-9
Use Shift with most
Save Configuration
Load Configuration
Alt-F1
Alt-F2
Alt-F3
Alt-F4
Alt-F5
Alt-F6
Alt-F7
Alt-F8
Reduce display to Stars & Lines
Reduce display to Stars only
Background
Twilight Mode
Mouse Display
Precession Toggle
Printer Port
Add Line Feeds?
Alt-F10 Aspect Ratio
(0=New Program Default)
Find next sunset or sunrise
+
=
/
.
Alt-F
Brighten Gray Colors
Dim Gray Colors
Toggle AM-PM/24 hour Time Display
Text Color
Reverse Text Toggle
Flip Hemisphere
-21DEFINITION OF SHAREWARE
Shareware distribution gives users a chance to try software
before buying it. If you try a Shareware program and continue
using it, you are expected to register. Individual programs
differ on details -- some request registration while others
require it, some specify a maximum trial period. With
registration, you get anything from the simple right to continue
using the software to an updated program with printed manual.
Copyright laws apply to both Shareware and commercial software,
and the copyright holder retains all rights, with a few specific
exceptions as stated below. Shareware authors are accomplished
programmers, just like commercial authors, and the programs are
of comparable quality. (In both cases, there are good programs
and bad ones!) The main difference is in the method of
distribution. The author specifically grants the right to copy
and distribute the software, either to all and sundry or to a
specific group. For example, some authors require written
permission before a commercial disk vendor may copy their
Shareware.
Shareware is a distribution method, not a type of software. You
should find software that suits your needs and pocketbook,
whether it's commercial or Shareware. The Shareware system makes
fitting your needs easier, because you can try before you buy.
And because the overhead is low, prices are low also. Shareware
has the ultimate money-back guarantee -- if you don't use the
product, you don't pay for it.
Support Policy
We at KlassM SoftWare are totally committed to offering the most
bang for the byte in astronomy software. We are proud of SkyGlobe,
and we want to make sure it works for you. If you have any problems,
please contact us at the address on the order form, or leave me a
note on CompuServe at 76207,3377. Since registered users have had
the opportunity to try SkyGlobe before they pay for it, we shouldn't
have too many problems. If some version change has made it impossible
to run SkyGlobe on your system, I will either do what I can to make
it work for you, or refund your money.
-22DISCLAIMER - AGREEMENT
Users of SkyGlobe 3.1 must accept this disclaimer of warranty: "SkyGlobe
3.1 is supplied as is. The author disclaims all warranties, expressed or
implied, including, without limitation, the warranties of merchantability
and of fitness for any purpose. The author assumes no liability for
damages,
direct or consequential, which may result from the use of SkyGlobe 3.1."
SkyGlobe 3.1 is a "shareware program" and is provided at no charge to the
user for evaluation. Feel free to share it with your friends, but please
do not give it away altered or as part of another system. The essence of
"user-supported" software is to provide personal computer users with
quality
software without high prices, and yet to provide incentive for
programmers
to continue to develop new products. If you find this program useful and
find that you are using SkyGlobe 3.1 and continue to use SkyGlobe 3.1
after
a reasonable trial period, you must make a registration payment of $20 to
KlassM SoftWare. The $20 registration fee will license one copy for use
on
any one computer at any one time. You must treat this software just like
a book. An example is that this software may be used by any number of
people and may be freely moved from one computer location to another, so
long as there is no possibility of it being used at one location while
it's being used at another. Just as a book cannot be read by two
different
persons at the same time.
Commercial users of SkyGlobe 3.1 must register and pay for their copies
of
SkyGlobe 3.1 within 30 days of first use or their license is withdrawn.
Site-License arrangements may be made by contacting Klassm Software.
Anyone distributing SkyGlobe 3.1 for any kind of remuneration must first
contact KlassM SoftWare at the address below for authorization. This
authorization will be automatically granted to distributors recognized
by the (ASP) as adhering to its guidelines for shareware distributors,
and such distributors may begin offering SkyGlobe 3.1 immediately
(However
KlassM SoftWare must still be advised so that the distributor can be kept
up-to-date with the latest version of SkyGlobe 3.1.).
You are encouraged to pass a copy of SkyGlobe 3.1 along to your friends
for evaluation. Please encourage them to register their copy if they
find
that they can use it. All registered users will receive a copy of the
latest version of the SkyGlobe 3.1 system.
Ombudsman Statement
"This program is produced by a member of the Association of Shareware
Professionals (ASP). ASP wants to make sure that the shareware
principle works for you. If you are unable to resolve a
shareware-related problem with an ASP member by contacting the member
directly, ASP may be able to help. The ASP Ombudsman can help you
resolve a dispute or problem with an ASP member, but does not provide
technical support for members' products. Please write to the ASP
Ombudsman at 545 Grover Road, Muskegon, MI 49442 or send a CompuServe
message via CompuServe Mail to ASP Ombudsman 70007,3536."