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- S K Y G L O B E 3.0
-
- A Shareware Product of Klassm Software
-
- Copyright (c) 1992 Mark A Haney
-
-
-
-
-
- Congratulations! You have a fully registered copy of Skyglobe, 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.
-
- 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
- at the end of this 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 ! ! !
-
-
- _______
- ____|__ | (R)
- --| | |-------------------
- | ____|__ | Association of
- | | |_| Shareware
- |__| o | Professionals
- -----| | |---------------------
- |___|___| MEMBER
-
- February 9, 1992
- SKYGLOBE 3.0 ORDER FORM
-
- Your friends can use this form to register a copy of SkyGlobe 3.0.
-
- Registration ($20) will entitle you to the following:
-
- 1) A copy of SkyGlobe with your Home Town as the default city.
- 2) A Handy SkyGlobe Reference Card.
-
-
- Shipping Address: Name:
- ........................................
- Street:
- ......................................
- City, ST, ZIP
- ................................
-
- Home Town:
- (Up to three permitted) .............................................
-
-
- Disk Type: 5 1/4" 3 1/2"
- (circle one)
-
- Default Video Mode: CGA Hercules EGA VGA
- (circle one)
-
-
-
- Please make checks ($20) payable to Klassm Software.
- MI residents must add 4% sales tax, for a total of $20.80.
-
- 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
-
-
- Credit Card Authorization Form:
-
- Card #__ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __
-
- Signature:_______________________________________________
-
- Date of Authorization:___________ Amount:__________ Expiration:______
-
-
- Thanks, and I hope you enjoy SkyGlobe!
-
-
-
- -3-
-
-
-
- Quick 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 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.
-
-
- As a fully 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, S for SVGA, and S2
- for alternate SVGA mode.
- 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 upper-
- lefthand 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 change the time? 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 started with
- SkyGlobe. More detailed descriptions of the commands appear in
- the following pages. Have fun!
-
-
- -4-
-
-
- SkyGlobe Command Descriptions
-
- As a registered user of SkyGlobe, you received a Handy Reference Card
- that will remind you of SkyGlobe commands. The inside of the Reference
- Card contains two lists of the 300 brightest stars, as well as lists
- of the constellations and Messier Objects. These lists will help you
- when using the Find object command.
-
-
- Time 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, or a century. Except for tiny changes due to
- leap years, only the planets change from year to year.
- Use the table below:
-
- Forward Backward
- 1 Minute Press 'T' Press 'Shift-T'
- 1 Hour 'H' 'Shift-H'
- 1 Day 'D' 'Shift-D'
- 1 Month (30 days) 'M' 'Shift-M'
- 1 Year 'Y' 'Shift-Y'
- 1 Century 'J' 'Shift-J'
-
-
- 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 com-
- puter. 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 '>' key '<' keys.
- V3.0 of SkyGlobe adds two new features to the Auto-Increment mode.
- 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 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.
-
-
- -5-
-
-
- Where 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 direction your feet are pointing. This is the View Dir-
- ection. 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 ap-
- pears 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.
-
-
- Lines And Labels
-
- One of the most useful features of SkyGlobe is its ability to
- quickly and easily change the lines and labels that help our eyes
- and minds make sense of the vastness of the sky. This can be very
- helpful to the novice just learning the 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. The constellations also have
- abbreviations available for display. Use 'F9' to display these three-
- letter abbreviations. The 1000 brightest stars can be labelled by
- using 'F8' to see more labels, and keep pressing it until the labels
- disappear if you want to see fewer, or use 'Shift-F8'.
- V3.0 of SkyGlobe has added the capability to display either an
- outline or a filled region to represent the Milky Way. Press 'K' or
- 'Shift-K' to scroll through the levels of display, which affect the
- types, brightnesses, and colors of the lines and regions.
-
-
- Messier Objects
-
- Labels for the Messier Object can be turned on or off with the
- 'F4' key. Use the Reference Card to learn the names of the important
- objects.
-
-
- -6-
-
-
- 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.
-
- 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 new 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.
-
- Keeping 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.
-
-
-
- -7-
-
- The 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 out-
- of-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 diff-
- erent '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 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. These planetary positions are now calculated on the fly in
- SkyGlobe 3.0. This is a bit slower and less accurate than previous ver-
- sions of SkyGlobe, but the added flexibility of dispensing with the
- data files is more than worth it. 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, 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.
- 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 al-
- ways 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 3.0 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. Currently the years
- are limited to the range 1900-2099, but this range will be greatly ex-
- panded shortly.
-
-
- -8-
-
- What Is A Toggle?
-
- Many of the display features in SkyGlobe can be instantly
- turned off or turned back on by pressing a single function key.
- A list follows.
-
- F5-Horizon line F9-Constellation Labels
- F6-Ecliptic line F10-Constellation Lines
-
- We haven't yet discussed a few features mentioned in the above
- function key list. SkyGlobe can display Right Ascension, Declination
- and Ecliptic lines to help you orient yourself on the celestial sphere.
- Notice how the Ecliptic passes through the constellations of the
- Zodiac, and how Orion lies right across the celestial equator.
- Try looking north with Auto-Increment mode on. Watch how the sphere
- appears to rotate, and how Polaris, very near the celestial pole,
- seems almost motionless.
-
- Using the Alt-key in conjunction with the function keys can be
- used to control some of the more obscure parameters in SkyGlobe 3.0.
-
- Alt-F1 reduces the display to stars and constellation lines only.
- Alt-F2 reduces the display to stars only.
- Alt-F3 gradually changes the background color from black to blue.
- Alt-F5 turns off the mouse position display, independently of the
- F2 Parameter Index. This makes mouse centering impossible.
- Alt-F6 toggles the Precession flag. With current range of only 200
- years, this in not all that valuable, but it does work.
- Alt-F7 toggles the printer port from LPT1 to LPT2.
- Alt-F8 controls whether line feeds are added to carriage returns
- while printing.
-
- Special Command Modes
-
- The SPACE bar, Home and End keys, and Alt and Ctrl keys, have special
- meaning in V3.0, as described on the Reference Card. The SPACE bar acti-
- vates Turbo mode, which takes the next keypress and continually feeds it
- into the program, until the SPACE bar is pressed again. The Home and End
- keys, for many commands, take the next keypress, and either minimize or
- maximize the program parameter altered by that key. The Alt and Ctrl keys
- often work as very small positive and negative increments for the command
- with which they are used. To illustrate this, 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.
-
-
- -9-
-
-
- Finding 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 cursor.
-
- 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.
-
-
- -10-
-
- 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!) Rather than
- quitting the program and choosing a different location from the menu,
- simply press 'L'. 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 3.0 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.
- 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. You
- may instantly change your location between the North and South Hemi-
- spheres by pressing 'Alt-F' to Flip between the two.
-
-
- Changing Your Environment
-
- No, this section has nothing to do with blowing up oil wells.
- SkyGlobe 3.0 adds the capability to customize many program settings.
- The file SKYGLOBE.REG allows you to specify three custom locations.
- These 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. 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.
- 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.
-
-
- -11-
-
- 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 LPT1. No matter your video type, a display will be
- created in VGA resolution for dot-matrix printing, or SVGA resolution
- for HP-compatible laser printing.
-
- What Else Is There?
-
- Only a few miscellaneous tidbits remain. In VGA and SVGA color modes,
- you can brighten or dim the colors with '+' and '-', and this bias can be
- saved in the .CF0 file. The text color can be changed with '/'. The type
- of Time display, either AM/PM or 24-hour, can be changed with '='. (I know
- these particular keys are meaningless, I ran out of useful mnemonics.)
- When Real-Time mode is active, an 'R' appears next to the time, or an 'S'
- for Sidereal Time. Daylight time is indicated with a 'D'.
-
- V3.0 of SkyGlobe now adds support for a mouse. The RA-Dec coordinates
- of the mouse cursor, along with the name of any object underneath it, will
- be displayed in the lower left-hand corner of the screen. 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.
-
- SkyGlobe 3.0 now offers a new projection for displaying the sky,
- which has become the default projection. It leaves the center, or more
- accurate, portion of the original SkyGlobe projection intact, but
- Inflates or stretches the edge portion, allowing for a more realistic
- portrayal of shapes near the edge. Use 'I' to toggle between the new
- and old projections.
-
- Finally, press 'Q' or ESC to return to DOS.
-
-
-
- Thanks For Your Support!
-
- I hope you enjoy SkyGlobe! As a fully registered user, 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.
- 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!
-
- -12-
-
-
-
- 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 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 ortho-
- graphic projection used in earlier versions of SkyGlobe (and still
- available through the use of the 'I' command) had fairly severe dis-
- tortions near the edges, and was only slightly faster.
-
- -13-
-
-
- Background 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 SKY7000.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,
- respectively.
-
- 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
- new version up and running on your system, don't hesitate to contact me.
- I can be reached at the address on the order form and Reference Card, or
- on CompuServe at 76207,3377.
-
-
-
- Thank you for supporting Shareware and...
-
-
- S K Y G L O B E ! ! !
-
-
- -14-
-
-
- Some Frequently Asked Questions
-
-
- How can I speed up SkyGlobe?
-
- There are really two 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 'F2' or 'Shift-F2'.
- 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 '>'.
-
- Why doesn't anything happen when I press 'V'?
-
- Either the date is not appropriate for Daylight Saving Time, or
- you chose a location that does not use it.
-
- Why do I get garbage when I try to print?
-
- When you print the screen by choosing 'P', you will be prompted
- to choose the appropriate printer type, either 9-pin, 24-pin, or
- HP-compatible laser printing. The only difference between the two
- dot-matrix modes is the line-spacing, and it is possible that the
- 9-pin choice will work better for some 24-pin printers. If you try
- print in laser mode on a dot-matrix printer, or vice versa, the results
- will be unsatisfactory. Printing on other devices, such as ink-jet or
- bubble-jet printers, should work, as long as you choose the correct
- mode that is emulated by your printer. If your printer is not connected
- to LPT1, you will not be able to print.
-
- 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 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 mode is a commonly used non-VESA mode supported by many cards. More
- SVGA support for other cards will be available soon; contact Klassm
- Software for an update if you are still having trouble. 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.
-
-
- DEFINITION 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.
-
-
- DISCLAIMER - AGREEMENT
-
- Users of SkyGlobe 3.0 must accept this disclaimer of warranty:
- "SkyGlobe 3.0 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 conse-
- quential, which may result from the use of SkyGlobe 3.0."
-
- SkyGlobe 3.0 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 3.0 and continue to use
- SkyGlobe 3.0 after a reasonable trial period, you must make a reg-
- istration 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 3.0 must register and pay for their
- copies of SkyGlobe 3.0 within 30 days of first use or their license
- is withdrawn. Site-License arrangements may be made by con-
- tacting Klassm Software.
-
- Anyone distributing SkyGlobe 3.0 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 3.0 immediately (However Klassm Software must still be
- advised so that the distributor can be kept up-to-date with the
- latest version of SkyGlobe 3.0.).
-
- You are encouraged to pass a copy of SkyGlobe 3.0 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 3.0
- system.
-
-
-
-