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C O S M O S Planetarium Simulator Version 6.11L Copyright 1988 11/1/88 by Gene W. Lee 1. Introduction Cosmos is a program which provides astronomical simulations the same way a planetarium does. Cosmos will show the past, present and future skies as viewed from Earth. It also shows the position of the planets in orbit around the Sun and gives specific data about the celestial bodies. Program options allow the user to select date/time of display, direction of view, viewer's latitude and longitude, screen updating parameters and much more. Using the display updating parameters Cosmos can display a complete days movement of the heavens, or demonstrate the retrograde motion of the planets by displaying the sky at the same time each consecutive day. Cosmos was written on a UNISYS IT with EGA graphics and a 80287. The program is intended to run on any DOS system that has VGA, EGA, or CGA graphics. Although the program will run in CGA mode, the display is very poor because of the lack of resolution and colors. If you must use CGA mode, try forcing Monochrome Hires mode. See program call options for details. The program will also run with or without a math co-processor, however, it is painfully slow without one because of the intense floating point arithmetic involved. If the version number displayed on the first screen ends with an 'L', this version of Cosmos is being distributed as a Limited Demonstration version. Its limitation is only that is will work only for the years 1986 through 1988. The Full Function version will work between the years 1700 and 2500. The full function version also includes over 2000 stars and messier objects. The Full Function version can be requested by sending a support donation using the form at the end of this document. 2. Horizon Display Description The Horizon display attempts to show the sky as seen from Earth when looking in specified direction at a specific time of day. The left side of the display is what would be seen over your left shoulder as is the right side over your right shoulder. The top of of the display shows what you would see directly over your head. You must realize that distortion increases as you approach the edges of the arc. Another way to think of what the display is representing is image you are sitting in the middle of the planetarium. You see in front of you half of the dome. The difference is that at the planetarium your field of view would not be large large enough to see the complete half dome all at one time, and with the program the complete half dome is plotted on the screen. The Moon is drawn in its approximate phase with the New Moon represented with an empty circle. The drawing of the phase of the Moon is rounded to the nearest quarter ( New, First Quarter, Half, Third Quarter, Full, etc.). By using menu selections you can control the brightness of the stars, direction of view, select Real Time display or a User defined time, change the update rate of the display and much more. As in all displays the Escape key exits from the display. See the Display Help menu for more information. Note that the time and date displayed at the top of the screen represent Local Time and assume that the system clock is set to daylight savings time when applicable ( see technical notes for more details on daylight savings time ). When 'Leave Trails' is turned on the time/date displayed on the left are the start time and the time/date on the right are the current time. CONTROL KEYS for this display are: p: Pause the updating of this display and put the display in PICK mode (See Pick Mode). Escape: Exit Pause/Pick Mode. s: Pick Star while in Pick Mode. Any key press releases pick. h: Highlight the constellation that contains the object that has been Picked. l: Dump current screen to an IBM compatible printer. (Option in Development Mode) 2.1 Pick Mode When in the horizon display mode the user has the option of picking an object (non-planet) on the display to find out what it is. If the cursor is within the capture range of an object it will lock on to that object and display information about it. If the cursor is not within the capture range of an object the Altitude/Azimuth and Right Ascension/Declination of the spot selected is displayed. After an object has been Picked, the user has the option of highlighting the constellation that contains the object that has been picked. HOW TO USE THIS FEATURE: While in the horizon display mode, press the 'p' key to enter Pick mode. After all objects on the display have been updated to reflect the displayed time, Pick mode will be entered. Move the cursor around the screen by pressing the arrow keys. For finer cursor movement press the SHIFT key along with an arrow key. When the cursor is pointing at the desired object press 's' to select. If the cursor is within the capture range of an object the cursor will first be repositioned to point at the object. A pop up window will then appear which will provide details about the object. Included in this information is -Altitude and Azimuth (See Technical notes for definition). -Right Ascension and Declination. -Apparent Magnitude of the object. -Constellation the object is part of. -Name of the object if known. -Spectral Type of the object. -Object Type (Star,Double star, nebula, etc.). If an object was selected the user has the option to Highlight the constellation containing this object. To highlight press 'h'. Any other key will release pop up window. 3. Orbital Display Description The Orbital Display attempts to show the position of the planets as they orbit the Sun. The view is from above the plane of the system with planets moving counter clockwise around the Sun. By using the control keys you can zoom in toward the Sun or back away from it. The 't' key toggles whether the planets leave a trail as they move. The control keys will also allow you to freeze the motion of the planets. As in all displays the Escape key exits from the display. See the Display Help menu for more information. Note that the time and date displayed at the top of the screen represent Local Time land and assume system clock is set to daylight savings time when applicable ( see technical notes for more details on daylight savings time ). When 'Leave Trails' is turned on the time/date displayed on the left are the start time and the time/date on the right are the current time. CONTROL KEYS for this display are: p: Pause the updating of this display t: Toggles whether planets leave a trail as they move +: Zooms in on the Sun -: Zooms out from the Sun l: Dump current screen to an IBM compatible printer. (Option in Development Mode) 4. Planet Position Display This screen provides numerical information about the planets, Sun and Moon's position as views from Earth. The right ascension and declination for each body is given along with its Altitude and Azimuth. Each time a key is pressed ( excluding the Escape key ) the display time is updated according to the *Update Mode and the fields are re-calculated and re-displayed. * Refer to Update Mode description of the Setup Time Menu. 5. Planet Distance Display This screen provides numerical information about the planets and Sun. It currently displays the distance from the Earth to each of the Planets and the distance from each of the Planets to the Sun. The distance is measured in Astronomical Units (AUs) and in Millions of miles. AUs are equal to 149.6 Million Kilometers or 92.96 Million Miles. Each time a key is pressed ( excluding the Escape key ) the display time is updated according to the *Update Mode and the fields are re-calculated and re-displayed. * Refer to Update Mode description of the Setup Time Menu. 6. Planet Rise Times Display This screen provides numerical information about the planets, Moon and Sun rise and set times. This display shows the rise and set time of each of the planets, the Sun and the Moon. The Total Rise column gives the amount of time the body is above the horizon. The Phase of each of the bodies is also listed. Each time a key is pressed ( excluding the Escape key ) the display time is updated according to the *Update Mode and the fields are re-calculated and re-displayed. * Refer to Update Mode description of the Setup Time Menu. 7. Menu Descriptions This section will describe the purpose and function of each of the menu screens. a. Main Menu DISPLAY TYPE is filled in with the type of display you wish to see. (Refer to description of each display type) 1 -Horizon 2 -Orbital 3 -Planetary Data 4 -Distance Data 9 -Help Menu for Display Control 0 -Exit Program VIEW DIRECTION is used to select which way you are looking when using the Horizon Display. Direction is the same as its measured using a magnetic compass. LEAVE TRAIL selects whether the bodies on the Horizon and Orbital display leave a trail behind them as they move. SETUP TIME MENU is used to change the display time, update mode and update rate. SETUP LOCATION MENU allows definition of where the observer is located on the Earth. SETUP STARS MENU is used to change parameters dealing with how stars are displayed on the Horizon Display. SETUP PLANETS MENU is used to enable/disable the display of each planet (including Sun and Moon). RESTORE MENU SETUP will reread menu.sav file and re-load the default menu setup that the program start up with. SAVE MENU SETUP will save the current state of the menu selections and definitions. NOTE: The saved menu configuration is read in at program startup. This will enable you to set such things as your longitude and latitude and have them come up as the default every time you run the program. Example, Go through all the menus setting up the parameters the way you they apply to your specific situation. Then select "Save Menu Setup" by entering a "y" on the Save Menu Setup line followed by pressing the Escape key. From now on the menus will be setup this way every time you start the program. b. Star Setup Menu This menu is used to configure how stars will be displayed when viewing the Horizon Display. Stars can be turned on and off and their apparent magnitude can be adjusted. DISPLAY STARS selects whether or not stars are displayed on the Horizon Display ( Note: our Sun is not considered in the set of stars but is treated more like a planet) FIRST CUTOFF, Stars with magnitudes between minus infinity and the First Cutoff are displayed in a high intensity white. SECOND CUTOFF, stars with magnitudes between the first cutoff and the second cutoff are displayed in a medium intensity white. THIRD CUTOFF, stars with magnitudes between the second cutoff and the third cutoff are displayed in a low intensity white. Stars with magnitudes dimmer than the third cutoff are not displayed. These cutoff values allow the user to limit the stars displayed to the stars that can actually be seen due to the amount of ambient city lights where they are located. HIGHLIGHT CONSTELLATIONS determines whether or not the constellation that the PICKED star is in is highlighted (See Pick Mode). c. Time Setup Menu This menu is used to define the time for which the display in drawn and to define how much time each consecutive display is advanced. UPDATE MODE, If System Clock (0) mode is selected then the system's clock is used to derive the time for each consecutive display and the value of Update Rate is ignored. Values other than System Clock use the User Defined Time described below and are incremented each consecutive display by adding the Update Rate to the displayed time according to the display mode. A Sidereal Day is one revolution of the Earth with reference to the stars ( instead of the Sun ). It is approximately equal to 23 hours and 56 minutes. A Lunar Day is one revolution of the Earth with reference to the Moon ( instead of the Sun ). It is approximately equal to 1 day and 50 minutes. UPDATE RATE defines how much time is added to each consecutive display. It is used when ever the 'System Clock' Update Mode is NOT selected. See Update Mode definition. MONTH, DAY, YEAR, HOUR, MIN, SEC are used as the User Defined Time. See Update Mode. * NOTE *: User defined time is specified in Local Time including Daylight Savings Time when applicable. d. Location Setup Menu This menu allows the user to define where they are located on the planet Earth. This information is not used in the Orbital Display. LONGITUDE is the observer's longitude on Earth. This value is used in the Horizon Display. West of the Prime Meridian is positive and East is negative. Example: Mpls, Mn. is approximately +90 Columbus, Ohio is approx. +80 LATITUDE is the observer's latitude on Earth. This value is used in the Horizon Display. North of the Equator is positive and South is negative. Example: Mpls, Mn. is approximately +45 Columbus, Ohio is approx. +40 TIME ZONE describes the difference between Greenwich time and local time. Example : Central Time is a +6. Eastern Time is a +5. e. Planet Setup Menu This menu is used to select which bodies will appear on the displays. Select 'y' to enable the display of each body and 'n' to disable it. Yes Carl Sagan, I know, the Sun and Moon are not really planets. 8. Files used by the program This section describes the files used by Cosmos. It explains their usage and where applicable, their format. a. STARFILE This file contains the star data used by Cosmos. Cosmos will read as many of the stars listed in the file as will fit into the available memory on your system. This file is in binary format and contains the following information. - Right Ascension of the object. - Declination of the object. - Magnitude (apparent) of the object. - Which constellation the object belongs to. This information is shown when a star is PICKED on the horizon screen. - The name of the object. This information is shown when a star is PICKED on the horizon screen. - Object Type which gives the type of body the object is. i.e. - Star, Double Star, Nebula, etc. This information is shown when a star is PICKED on the horizon screen. - Spectral Type of the object. This information is shown when a star is PICKED on the horizon screen. b. *.BGI Files These files contain information that the program uses to implement the different graphics modes. *No longer needed. c. *.CHR Files These files contain information that the program uses to implement the different character fonts. *No longer needed. d. MENU.SAV This is the file used to save the current setup of the menus. Refer to it's definition under the Save Setup section of the Main Menu description. Every time Cosmos is started, this file is read ( if it exists ) and the menu default parameter are loaded from it. This file is also read to re-load the default menu parameters on the 'restore default menu' option. e. COSMOS.DOC This document in non-wordstar format. f. COSMOS.WS This document in wordstar format. g. COSMOS.EXE The executable program. 9. Technical Notes a. GMT Time / Local Time /Daylight Savings Time Cosmos thinks in terms of Greenwich Mean Time but interfaces with the user in Local Time. Cosmos uses the value you set in TIME ZONE ( see the Location Menu ) to make this correction. Your system clock should be set to the correct local time. This includes daylight savings time if applicable. If daylight savings time is not instituted where you are or you do not want to set your system's clock in daylight saving time, Cosmos can be called with the 'n' option. This will instruct the program not to make any corrections for daylight savings time and will expect the clock to be set to Local Standard time. NOTE: Daylight Savings Time is assumed to begin on the FIRST Sunday of April and end on the LAST Sunday of October. b. Phase The phase of a body is defined as follows: ( using the Moon phases as an example ) 0,360 degrees is the New Moon. 270 degrees is the first half ( Waxing half ). 180 degrees is the full Moon. 90 degrees is the last half ( Waning half ). This applies to all other solar system bodies. vc. Altitude and Azimuth Altitude and Azimuth describe the elevation and compass direction from the observer. Altitude is measured in degrees above the horizon. 0.0 is on the horizon and 90.0 is straight up. A negative altitude implies that the object is below the horizon. Azimuth is measured in degrees from North. 0.0 is North, 90.0 is East, 180.0 is South and 270.0 is West. d. AU Astronomical Units Astronomical Units are a measure of length which are roughly equal to the radius of the Earth's orbit around the Sun at its farthest point. 1 AU = 149.6 Million kilometers. e. Formulas used by the program The formulas used by this program were derived using the book 'Practical astronomy with your calculator' written by Duffet Smith, Peter. Published by Press Syndicate of the University of Cambridge 1979, 1981. f. Development System This program was written using Turbo-C 1.5 on a Unisys IT with an Ega display and a 80287. g. Program Accuracy The accuracy of the positions calculated and plotted vary at most by a couple of minutes of arc. This will produce plots that are well within the needs of an amateur astronomers. h. Astronomical Experiments These are just some of the ways you can use Cosmos to watch the heavens move. Many more are possible, its up to your imagination. -- Watch a complete day go by in minutes. To see the Sun, Moon and the planets traverse the sky while you watch it a simple task. To see this motion set the Update Mode to "Increment by minutes" and set the Update Rate to four or five. Turn off the stars to increase the display update speed. Look at the southern horizon and watch the days go by. -- Watch the stars circle the North Star as the Earth rotates through a day. The North Star is approximately aligned with the Earth's axis of rotation. If you photograph the northern sky with long exposures you will get a picture with the stars forming concentric circles around the North Star. To create this picture using Cosmos, set up the horizon display to view the northern sky from a northern latitude. Turn on "Bodies Leave Trails". Set the Update Mode to "Increment Minutes" and the Update Rate to about 5. As you watch each frame of the display progress the concentric circles appear. -- Watch the Sun's height in the sky at noon change through out the year. As the Earth travels around the Sun the angle between an observer on the Earth and the Sun changes. On the Winter Solstice the Sun is low in the sky at noon and on the Summer Solstice it reaches its high point. To see this you can use the program to display the position of the Sun every day at noon. Set the "Bodies Leave Trails" to YES. Set the Update Mode to Increment Day and set the Update Rate to one. Displaying the southern horizon you will see the Sun Rise as Summer approaches and then began to fall as Fall leads to Winter. -- Watch the movement of the Sun during a Summer day above the Arctic Circle. At latitudes above the Arctic Circle the Sun will not set on the longest day of the year, June 21. To recreate this 24 hour day set the viewers latitude to a value between 66.5 and 90.0. Set the time of display to be June 21 of any year. This can be accomplished by setting the Update Mode to Increment Minutes and the Update Rate to about five. If you watch the Suns movement during one full day you will notice that the sun did not rise and set but rather that it followed a path of equal height around the horizon. If you display Planetary Data (from the main menu) you will notice that the Rise/Set time for the Sun is "Never Sets". -- Watch the retrograde motion of the planets. The retrograde motion of the planets refers to the way they wander through the constellations from night to night. In fact, the word planet means wanderer. To see this motion, set the Update Mode to "Increment Sidereal Day" and set the Update rate to two or three. This mode updates the display by the same amount of time it takes the stars to return to the same position in the sky each consecutive night. Turning off the display of the Moon and Sun is recommended for this experiment If you set "Bodies Leave Trails" the planets will draw their paths through the stars as they move. A recommended Date/Location setup for this display is; look at the southern horizon from North America at Midnight on September first. With Stars displayed it can take up to fifteen minutes (with math co-processor)to get an interesting display. i. History of Enhancements Revision 5.73 5-9-88 First Public Release Revision 5.74 5-25-88 New Memory Model allows all stars in starfile to fit into memory. Problem with program stating "Rename program to cosmos.exe" when DOS switch char is changed has been fixed. Attempted fix for intermittent math error on some systems was made. (time will tell) Revision 5.75 6-1-88 Program uses expanded star file which now includes star names/descriptions and also has more stars. Revision 5.76 6-11-88 Added menu selection to re-read the default menu setup from file MENU.SAV. Revision 5.77 6-14-88 Fixed two coding bugs which caused floating point math errors. Revision 5.78 6-20-88 Test of Star Pick functions (UNRELEASED) Revision 5.79 6-22-88 Changed format of starfile to binary file. Stars load in 1/4 the old load time. Revision 5.80 6-24-88 Fixed bug in program that incorrectly rounded star magnitude cutoff values to integers. Revision 5.81 6-25-88 Added constellation highlighting feature when a star is Picked (See horizon display for details). This new menu option causes old menu.sav files to become invalid. Execute Menu Save option again. Changed the color of Neptune so that it is different than Jupiter. Revision 5.82 6-26-88 First version to have Pick cursor working. Cursor shape needs more work. Revision 5.83 6-29-88 Method for highlighting constellations changed; no longer use menu option to determine whether or not to highlight. Instruction on how to use Pick Mode are now given interactively to the user. Revision 5.84 7-2-88 Program now uses and displays constellation names instead of IAU designation. Revision 5.85 7-3-88 Fixed problem that stars which are already plotted on the horizon display are erased because another star tries to plot on top of it. Fixed problem where pick display where it left out the negative sign on negative declinations. Revision 5.86 8-7-88 Combined Program Logo screen and the star reading screen into one Logo screen. Revision 5.87 8-14-88 Added 'Up' field to Planetary Data Display. This field contains an up-arrow if the body is above the horizon at the displayed time. Revision 5.88 8-18-88 First TEST version released with print out option on the horizon screen. Revision 5.89 8-29-88 Made changes to the horizon printout routine. Made Internal changes. Revision 5.90 9-6-88 Changed time printout on Horizon display to show start time and current time when 'leave trails' is on. This then shows how long it took to make the trails on the screen. Revision 5.91 9-9-88 Made same change as 5.90 to the Orbit display. Revision 6.00 9-10-88 Fix to compiler now allows program to be compiled using Huge model. This allowed the following enhancements. Put 'Display Help' function back in. Did more work on Horizon display printout feature. Added screen dump function to the Orbit display. Incorporated .BGI and .CHR files into the program, they are no longer needed. Added update incremet of 'Lunar Day' to time setup menu. Revision 6.01 9-12-88 Added 'Planet Distances' display. Revision 6.02 9-13-88 Changed 'Planet Distances' display to show distance of planets from Sun and from Earth. Revision 6.03 9-15-88 Added distance measurement of Miles on the 'Planets Distances' display. Revsion 6.04 9-16-88 Fixed memory allocation problem on systems with 256k of memory. Added messages to confirm writing and reading of the menu save file. Revision 6.05 9-17-88 Split out Planetary data display into three seperate displays. 1-Planet Positions 2-Planet distances and 3-Planet rise/set times. Revision 6.06 9-18-88 Added check in display printout routine to check for printer being off line. Revision 6.07 9-21-88 Cosmos now displays the update mode and rate at the bottom of the horizon display. Revision 6.08 9-23-88 Total-Rise-Time column added to the Rise-Times display. Revision 6.09 10-1-88 Cursor (in pick mode) now screen wraps instead of stopping at the screen edges. Revision 6.10 10-22-88 Enhance program to use COSMOS environment variable. ( see Program Call section of document ) Revision 6.11 11-1-88 Added Monochrome (640x200) mode as a valid display mode. j. Caveats Since this program was written on an Ega system, the displays were optimized to look best in EGA and VGA modes. Although the program does run in CGA mode, the display is of extremely low quality ( due to the low resolution ) and is not useful if any detail is required. The program is very math intensive and needs a math co-processor to run effectively. The program will run without math co-processor support, however the program becomes limited in its display updating due to the long calculation times of the math emulation routines. If you have a math co-processor and are interested in seeing just how slow this program will run without it, do the following. Before executing Cosmos ( at the DOS prompt ), type "set 87=n". The program, when run, will detect this value and use floating point emulation routines instead of the math chip. Now that you have seen what a good investment your math co-processor is, you can re-enable it by exiting Cosmos and typing "set 87=y". NOTE: the " (Quotes) were not supposed to be typed in. k. Program Call After moving to the directory which contains Cosmos.exe, the .BGI and .CHR files, menu.sav and the starfile, the program should be called as follows: COSMOS {-options} Current options are: n -Do not correct for Daylight Savings Time. v -Force VGA display mode. (640x480, 16 colors) e -Force EGA display mode. (640x350, 16 colors) c -Force CGA display mode. (320x200, 4 colors, palette 1) m -Force Monochrome display Mode. (640x200, 2 colors) Examples: cosmos -n { Would turn off DST correction } cosmos -vn or cosmos -v -n { Would turn off DST correction AND force the program to override the detected graphics mode and use VGA graphics display mode instead. *** NOTE ***: OPTIONS ARE CASE SENSITIVE. If there is an environment variable COSMOS set, the program will use its value as the path to access the files used by the program. As an example, add the line SET COSMOS=C:\COSMOS\ to the autoexec.bat file (assuming the directory c:\cosmos contains the cosmos program and all its related files). Now change to any other directory, say the root directory. Execute the cosmos program (c:\cosmos\cosmos). Cosmos will now be able to find its files even though you are not in the cosmos directory. 10. Copyright Notice Everyone who purchase the full-function version will be notified of updates and enhancements to the program. If the version number displayed on the first screen ends with an 'L', this version of Cosmos is being distributed as a Limited Demonstration version. Its limitation is only that is will work only for the years 1986 through 1988. The Full Function version will work between the years 1700 and 2500. The full function version also includes over 2000 stars and messier objects. The Full Function version can be requested by sending a support donation using the form at the end of this document. Limitations on distribution and use include the following: No responsibilities for the operation of Cosmos is assumed or implied by its author. The user of Cosmos uses the program at their own risk. The author assumes no responsibly for damages caused by use of this program. This program and its documentation may not be distributed if any changes have been made. The copyright notice and statement of authorship must not be modified or removed. All copies of the Full-Function (Unlimited) version must be registered and may not be distributed. Cosmos may not be distributed for profit. Use the following form to purchase the Full-Function (Unlimited) version of Cosmos. Remit to: Gene W. Lee Order Form 7500 Colorado Ave N. 6.11 Brooklyn Park, Mn. 55443 Please send: ____ Cosmos Disk (Full-Function Version)....... @ $ 25.00 ea. $ ____ (includes program and manual on disk) (Minnesota residents please add 6.0% sales tax) Tax ____ Total $ ______ Payment by: ( ) Check ( ) Money Order Name: ____________________________________________________________ Organization: ________________________________________________________ Address: ____________________________________________________________ : ____________________________________________________________ : ____________________________________________________________ Day Phone: _________________________ Eve: ___________________________ ORDERS OUTSIDE THE US: Use check or Money Order drawn on US bank in US dollars. Add $5 (per copy) for non-US shipping of orders containing disks and manuals. Sorry, no C.O.D. orders will be accepted. WARNING: YOU MAY NOT USE COSMOS WITHIN YOUR ORGANIZATION WITHOUT A PURCHASE OR LICENSE ARRANGEMENT. WARNING: The author assumes no responsibility for damages caused by uses of this program. PRICES SUBJECT TO CHANGE WITHOUT NOTICE. System Type Survey Computer Type ______________________________________________ System Memory _______ Monitor Type ____________ Math Chip _______