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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.