












                            "THE EARTH CENTERED UNIVERSE"
                            "THE EARTH CENTERED UNIVERSE"
                            "THE EARTH CENTERED UNIVERSE"
                             Sky Visualization Software
                             Sky Visualization Software
                             Sky Visualization Software

                                    User's Manual
                                    User's Manual
                                    User's Manual

                                     Version 1.1
                          Shareware and Registered Versions
                               Released in March 1992

                            for Microsoft(R) Windows 3.0





















                                     Written by:
                                    David J. Lane
                                 4-26 Randall Avenue
                                Halifax, Nova Scotia
                                   Canada B3M 1E2
                            Compuserve E-Mail: 71601,247
                       Internet E-Mail: lane@oceanroutes.ns.ca

                                 Manual Revision 1.0





                                  TABLE OF CONTENTS
                                  TABLE OF CONTENTS
                                  TABLE OF CONTENTS

                 1. Getting Started ..................................4
                 1.1 Registration of ECU .............................4
                 1.2 System Requirements .............................5
                 1.2 Installation Instructions .......................6
                 1.3 Starting ECU ....................................7
                 2. Introduction .....................................7
                 2.1 The Status Display ..............................8
                 2.2 The Sky Display .................................9
                 2.3 Mouse Operations ................................10
                 2.3.1 Left Mouse Button .............................10
                 2.3.1 Right Mouse Button ............................11
                 2.4 On-Screen Controls ..............................11
                 3. Menu Selections ..................................12
                 3.1 File Menu .......................................13
                 3.1.1 Open... .......................................13
                 3.1.2 Save ..........................................13
                 3.1.3 Save As... ....................................14
                 3.1.4 Exit ..........................................14
                 3.2 Edit Menu .......................................14
                 3.3 Set Menu ........................................14
                 3.3.1 Time ..........................................14
                 3.3.1.1 Enter Local Time ............................14
                 3.3.1.2 Enter Universal Time ........................15
                 3.3.1.3 Use System Time .............................15
                 3.3.1.4 Local Time Format ...........................15
                 3.3.1.5 Daylight Savings ............................15
                 3.3.2 Geographic Location ...........................15
                 3.3.2.1 By Latitude/Longitude .......................15
                 3.3.2.2 By City/Town ................................16
                 3.3.3 Solar System ..................................16
                 3.3.3.1 High Accuracy Calculations ..................16
                 3.3.3.2 Precess to Sky Display ......................17
                 3.3.3.3 Nutation ....................................17
                 3.3.3.4 Aberration ..................................17
                 3.3.3.5 Light Travel Time ...........................17
                 3.3.3.6 Observer's Parallax .........................17
                 3.3.4 Define Comet Orbit ............................18
                 3.3.5 Sky Background Color ..........................19
                 3.4 Field Menu ......................................19
                 3.4.1 Magnitude Limits... ...........................19
                 3.4.2 Object Selection... ...........................19
                 3.4.3 Planets... ....................................20
                 3.4.4 Sun ...........................................20
                 3.4.5 Moon ..........................................20
                 3.4.6 Grid ..........................................20
                 3.4.7 Lines/Points ..................................20
                 3.4.8 Labels ........................................21
                 3.4.9 Zoom In Full ..................................21
                 3.4.10 Zoom Out Full ................................21
                 3.5 Center Menu .....................................21
                 3.5.1 On RA/Dec... ..................................21
                 3.5.2 On Constellation... ...........................22


                                          2





                 3.5.3 On Bright Star... .............................22
                 3.5.4 On Messier Object... ..........................22
                 3.5.5 On Solar System Object ........................22
                 3.5.6 On Point on Horizon ...........................22
                 3.5.7 On Database Search... .........................23
                 3.6 Animation Menu ..................................23
                 3.6.1 Start .........................................24
                 3.6.2 Stop ..........................................24
                 3.6.3 Forward One Step ..............................24
                 3.6.4 Reverse One Step ..............................24
                 3.6.5 Trails On .....................................24
                 3.6.6 Maximum Trails... .............................24
                 3.6.7 Lock On Current RA/Dec ........................25
                 3.6.8 Lock On Current Azim/Alt ......................25
                 3.6.9 Lock On Solar System Object ...................25
                 3.6.10 Time Direction ...............................25
                 3.6.11 Time Step ....................................25
                 3.6.12 Animation Speed... ...........................26
                 3.7 About Menu ......................................26
                 4. Databases ........................................26
                 4.1 Stellar Database ................................26
                 4.2 Deep Sky Database ...............................27
                 5. Identify Objects .................................31
                 6. Printing Star Charts .............................31
                 7. The Future of ECU ................................32































                                          3







            1. Getting Started
            1. Getting Started
            1. Getting Started

                 Thank you for choosing to try "The Earth Centered
            Universe", ECU for short.  ECU is a Sky Visualization
            Program capable of simulating many of the phenomenon of the
            country night sky.  This includes the stars, planets, sun,
            and moon, comets, and "deep sky" objects.  ECU is designed
            as an observing tool for the observing amateur astronomer,
            but is equally useful to the "armchair" astronomer or other
            interested person.

                 Many of the concepts and terms used in this manual are
            common in amateur astronomy, but may not be familiar to all
            users.  The author recommends the purchase of a good
            beginner book in astronomy as a guide to the understanding
            of the concepts provided by this program.  An excellent
            beginner's book is: NIGHTWATCH: An Equinox Guide to Viewing
                                NIGHTWATCH: An Equinox Guide to Viewing
                                NIGHTWATCH: An Equinox Guide to Viewing
            the Universe
            the Universe
            the Universe by Terence Dickinson, which is available in
            most well stocked bookstores or libraries.

                 ECU is designed to operate on a PC from within the
            Microsoft(R) Windows 3.0 environment.  This environment
            provides all of the "tools" necessary to support a highly
            graphical program like ECU.  This manual assumes the user is
            familiar with the operation of typical Windows 3.0 programs.

                 ECU was written, because of the obvious lack of good,
            reasonably priced astronomy programs.  Most "commercial"
            software products (and the author has purchased three of the
            high profile programs) suffer from very awkward (not
            intuitive at all) user interfaces and ssllloooowwwww
                                                  ssllloooowwwww
                                                  ssllloooowwwww
            operation (especially without a math processor).  ECU,
            therefore, attempts to fill an obvious need.


            1.1 Registration of ECU
            1.1 Registration of ECU
            1.1 Registration of ECU

                 A large amount of effort in software development has
            gone into this, the first release, of "The Earth Centered
            Universe".  This included a round of beta testing and user
            feedback which resulted in many changes and a wish list from
            Earth to the Moon.

                 In order to ensure that ECU is supported and greatly
            improved in the future, I ask that you register ECU.
            Registration will bring a laser printed manual and an
            enhanced version of ECU.  This enhanced version includes
            several databases, which are too large to distribute by
            normal shareware methods (bulletin board systems).  Also,
            several computational enhancements (which require one of the
            database files) are enabled in the REGISTERED VERSION.



                                          4





                 I ensure you that the SHAREWARE VERSION is not
                                                            not
                                                            not
            "crippled" software.  It only lacks some of the advanced
            features, such as identification of stars, descriptions of
            "deep sky" objects, ultra-high accuracy solar system
            calculations (lower accuracy versions are included), comets,
            etc.  The executable file is the same.

                 A form is provided at the back of this manual for
            registering ECU.

                 The author would be most pleased in hearing your
            comments and suggestions for improvements of ECU or this
            manual.  ECU is a SHAREWARE product, thus is user supported.
            I can be reached at any of the addresses (post office and e-
            mail) listed on the cover page of this manual.


            1.2 System Requirements
            1.2 System Requirements
            1.2 System Requirements

                 As stated in section 1.0, ECU operates within the
            Microsoft(R) Windows 3.0 environment.  It will not run under
            DOS alone.  However, it has been tested for operation in the
            soon to be released OS/2 2.0.  The minimum system
            requirements are listed below:

            Hardware:           286/386/486 100% PC Compatible Computer
            Math Co-processor:  80x87 supported, but not required
            Software:           DOS 3.x or higher
                                Microsoft Windows 3.0 or higher
                                (standard or enhanced mode)
            Memory:             Minimum 600K bytes free from
                                within Windows
            Disk Capacity:      SHAREWARE VERSION - 450K bytes
                                REGISTERED VERSION - 1.8M bytes
                                WITH FULL SAO STAR DATABASE - TBD
            Graphics Card:      An EGA or better graphics card
            Monitor:            Color required for good screen displays
            Mouse:              Windows compatible

                 ECU has been tested with slower 286-based computers and
            operates perfectly satisfactorily with them.  In fact it
            operates faster on a 286 computer than many commercial
            programs operate on the author's 386!

                 The use of a math co-processor is supported, but not
            required.  With most commercial programs, this statement
            means that it works, but is untolerably slow!  ECU's sky
            drawing routines are written entirely in integer math, thus
            operate quickly with or without the math processor.  During
            development, the author's computer did not have a math co-
            processor.

                 The math processor, however, does speed up planet, sun,
            moon, and comet orbit calculations significantly.


                                          5





            1.2 Installation Instructions
            1.2 Installation Instructions
            1.2 Installation Instructions

                 ECU is distributed as one file (ECU.ZIP
                                                 ECU.ZIP
                                                 ECU.ZIP) in ZIP
                                                             ZIP
                                                             ZIP
            compressed format.  Any ZIP extraction program, such as
            PKUNZIP
            PKUNZIP
            PKUNZIP from PKWare, Inc., can be used to extract the
            individual files from the compressed file.  The compressed
            file contains the following files for the SHAREWARE and
            REGISTERED VERSIONS:

                                  SHAREWARE VERSION

            ECU.EXE        - the main executable program file
            ECU.CFG        - the default configuration file
            SAO1.ECU       - the main star file
            SAC1.ECU       - the main "deep sky" object file
            CONS.ECU       - the constellation data file
            LABELS.ECU     - the text labels data file
            LOCATION.ECU   - the geographic location data file
            MANUAL.TXT     - this manual


                                 REGISTERED VERSION

            ALL ABOVE FILES PLUS:

            SAO2.ECU       - the secondary star file
            SAC2.ECU       - the secondary "deep sky" object file
            PTERMS.ECU     - the orbital terms used for high accuracy
                             calculations
            PINDEX.ECU     - the index file for PTERMS.ECU

                 Installation of ECU is straight forward.  The example
            below assumes the use of PKUNZIP 
                                     PKUNZIP 
                                     PKUNZIP (it must be in the path),
            that your hard disk is drive 'C', and your floppy disk is
            drive 'A'.  You can install ECU from DOS or from a "DOS
            Window" within Windows 3.0.

                                               TYPE
                                               TYPE
                                               TYPE

            1. Log to your hard disk:          C: <return>
                                               C: <return>
                                               C: <return>
            2. Make a directory to store ECU:  MD \ECU <return>
                                               MD \ECU <return>
                                               MD \ECU <return>
            3. Change to the ECU directory:    CD \ECU <return>
                                               CD \ECU <return>
                                               CD \ECU <return>
            4. Install the ECU disk in drive 'A'
            5. Extract the files from ECU.ZIP: PKUNZIP A:ECU <return>
                                               PKUNZIP A:ECU <return>
                                               PKUNZIP A:ECU <return>
            6. Start Windows:                  WIN <return>
                                               WIN <return>
                                               WIN <return>
               (ignore if already running)
            7. Start the "File Manager"        use the mouse
                                               use the mouse
                                               use the mouse
            8. Open the ECU directory such that the ECU.EXE file is
               visible.
            9. Arrange the screen so that ECU.EXE and a suitable program
               group in the "Program Manager" are both visible.
            10.Drag ECU.EXE from the "File Manager" to the "Program
               Manager".  A colorful Icon should appear.
            11.  Proceed to section 1.3: Starting ECU.


                                          6







            1.3 Starting ECU
            1.3 Starting ECU
            1.3 Starting ECU

                 ECU is started by double-clicking the ECU Icon.
            Loading ECU typically takes less than 15 seconds, however,
            the SHAREWARE version takes somewhat longer the first time
            it is started.  This is because the file MATH.ECU needs to
            be created.  This file is used by ECU to speed up its sky
            drawing functions.  It is not distributed in the SHAREWARE
            version so as to reduce the "download" time (and therefore
            the cost) of ECU from bulletin boards.  Subsequent startups
            will occur normally.

                 Before the "main window" appears, several data files,
            plus the configuration file are loaded into memory.  If any
            problem is encountered while loading ECU (due to bad or
            missing files, not enough memory, etc.), a small dialog box
            displaying a descriptive message is displayed on the screen.
            Pressing 'OK' will return control to Windows 3.0.

                 If all is successful, the opening screen will appear
            greeting the user with a colorful display of the
            constellation of ORION.

                 At this time, only one copy of ECU can be running at
            any one time.  If the user attempts to run a second copy of
            ECU, a small dialog box will appear describing the problem.

                 The ECU "main window" always begins centered on the
            screen, however, it is designed it operate "full screen".
            Press the "maximize" button to facilitate this.

                 By default, ECU always uses the configuration file
            "ECU.CFG" located in the current directory.  If a file name
            is specified on the command line, ECU uses the specified
            file.  This is useful for setting up ECU 'icons' to quickly
            bring up saved astronomical events.

                 I suggest you read sections 2. and 3. next, which
            introduce the operation of the program, and address all of
            the menu selections.  If you just want to explore, that's
            fine, too.  I think you will find ECU quite intuitive.
            Section 4. then describes the built-in databases.


            2. Introduction
            2. Introduction
            2. Introduction

                 This section assumes that ECU is installed and is
            running.  As indicated in Section 1.3, ECU runs optimally
            "full screen", which is obtained by pressing the "maximize"
            button.




                                          7





                 Mouse operations are integral to the operation of ECU,
            and will be described in Section 2.3.  The on-screen
            controls, such as the check boxes and scroll bars will be
            described in Section 2.4 and the menu selections in Section
            3.  But first, the on-screen status displays and sky display
            area will be described.


            2.1 The Status Display
            2.1 The Status Display
            2.1 The Status Display

                 The left portion of the ECU window is used up by the
            status display area.  This area is contains the following
            items:

            a)   Geographic Location
                 Geographic Location
                 Geographic Location - the top line shows the city where
                 the observer is located.  If a city was not selected
                 (but rather a specific latitude/longitude was entered),
                 the message "By Lat/Long" will be displayed.
                 Immediately below, the latitude (Lat) and longitude
                 (Long) of the observer is displayed as degrees and
                 minutes.  Positive latitudes are North of the equator
                 and positive longitudes are West of the Greenwich
                 meridian.  To set your geographic location, see section
                 3.3.2, which describes the "Set -> Geographic Location"
                 menu selections.

            b)   Local Mean Time (LMT)
                 Local Mean Time (LMT)
                 Local Mean Time (LMT) - contains the date and time of
                 the local civil time.  The date is always in the format
                 year/month/date.  The time is either displayed as hh:mm
                 in 24 hour time or hh:mmpm in am/pm format.  See
                 section 3.3.1.4.

            c)   Greenwich Mean Time (GMT)
                 Greenwich Mean Time (GMT)
                 Greenwich Mean Time (GMT) - contains the date and time
                 at the Greenwich meridian.  The date is always in the
                 format year/month/date.  The time is always displayed
                 as hh:mm in 24 hour time format.

            d)   Right Ascension (RA)
                 Right Ascension (RA)
                 Right Ascension (RA) - contains the right ascension of
                 the center of the sky display.  It is formatted in
                 hours and minutes as hh:mm.m.

            e)   Declination (Dec)
                 Declination (Dec)
                 Declination (Dec) - contains the declination of the
                 center of the sky display.  It is formatted in degrees
                 and minutes as +dd mm'.

            f)   Azimuth (Azim)
                 Azimuth (Azim)
                 Azimuth (Azim) - contains the azimuth of the center of
                 the sky display.  The azimuth is the angle, in degrees
                 and minutes, from the Northern horizon towards the East
                 at the current Date and Time and Geographic Location.

            g)   Altitude (Alt)
                 Altitude (Alt)
                 Altitude (Alt) - contains the altitude of the center of
                 the sky display.  The altitude is the angle, in degrees
                 and minutes, measured vertically from the horizon at
                 the current Date and Time and Geographic Location.


                                          8






            h)   Field Size (Field)
                 Field Size (Field)
                 Field Size (Field) - contains the number of vertical
                 degrees currently shown in the sky display.  The
                 minimum field size is 1 degree and the maximum is about
                 60 degrees.

            i)   Magnitude (Mag)
                 Magnitude (Mag)
                 Magnitude (Mag) - contains the minimum magnitude for
                 which stars are displayed in the sky display.  This
                 number is usually the same as that set in the "Set ->
                 Magnitude Limits..." menu selection.  If the field size
                 is larger than 25 degrees the minimum stellar magnitude
                 is 6.5 and if larger than 45 degrees, the minimum is
                 5.5.  See section 3.4.1, which describes the "Set ->
                 Magnitude Limits..." menu selection.


            2.2 The Sky Display
            2.2 The Sky Display
            2.2 The Sky Display

                 The right portion of the ECU window is the sky display
            area.  The sky display area displays celestial objects using
            one of two "projections".  These two projections were
            selected for speed of their speed of calculation, however
            there is some distortion at the limits of their usefulness.

                 When displaying the sky from -45 to +45 degrees
            Declination, a simple modified Mercator projection is used.
            This projection causes the objects at high Declinations to
            be distorted (spread-out), most noticeable in constellations
            like Ursa Major (the big dipper).  This is the same
            distortion that makes Canada appear much larger than the
            United States on world maps with similar projections (Canada
            is only about 10% larger).

                 When displaying the sky either North of +45 or South of
            -45 degrees in Declination, the Zenithal Equidistant
                                            Zenithal Equidistant
                                            Zenithal Equidistant
            Projection
            Projection
            Projection is used.  This projection is quite good, but does
            spread out objects a bit at low Declinations.

                 With both projections, North is always up (South is
            down) and East is to the right (West is to the left).

                 The objects and items displayed in the sky display area
            are listed below.  Each will be discussed in detail in
            sections 3. and 2.4 by the specific menu selection or screen
            resource which controls their operation.

            a)   Grid
                 Grid
                 Grid - the coordinate grid helps illustrate the sky
                 projections just described.  Lines of Right Ascension
                 are drawn every hour (course grid) or every 20 minutes
                 (fine grid).  Lines of Declination are drawn every 10
                 degrees (course grid) or every 5 degrees (fine grid).





                                          9





            b)   Stars
                 Stars
                 Stars - stars are displayed as varying sized dots
                 according to the star's brightness.  The larger the
                 dot, the brighter the star.

            c)   Lines
                 Lines
                 Lines - there are many lines displayed by ECU.  These
                 include the constellation lines, horizon line, and
                 ecliptic line.  Markers are also displayed at the
                 Zenith (the overhead point) and the North and South
                 poles.

            d)   Labels
                 Labels
                 Labels - there are text labels displayed for solar
                 system objects, bright stars names, Messier objects,
                 constellation names, and labels for the ecliptic and
                 horizon lines, and markers.

            e)   Solar System objects
                 Solar System objects
                 Solar System objects - the planets, sun, moon, and
                 comets are displayed.  The sun and moon are displayed
                 to their correct size and the phase of the moon is
                 shown.  Planets are displayed as either a point or by
                 their standard symbol.  Comets as displayed as points.
                 Comets are not available in the SHAREWARE VERSION of
                 ECU.

            f)   Deep sky objects
                 Deep sky objects
                 Deep sky objects - deep sky objects are displayed in
                 six different categories.  These are Galaxies, Open
                 Clusters, Globular Clusters, Bright Nebulae, Planetary
                 Nebulae, and Other; each displayed using a different
                 symbol.  


            2.3 Mouse Operations
            2.3 Mouse Operations
            2.3 Mouse Operations

                 The mouse forms a vital part of the ECU user interface
            and has many uses from within ECU.  The cursor (the shape of
            the mouse pointer) is used to inform the user of how the
            mouse is currently being used.  If it is a cross-hair, it is
            used for selecting a window, identifying an object,
            centering, or measuring an angle.  The cursor is always a
            cross-hair while in the sky display area.  If it is an
            arrow, it is used for operating the scroll bars or buttons.

                 Each mouse button will be described separately in the
            next two sections.


            2.3.1 Left Mouse Button
            2.3.1 Left Mouse Button
            2.3.1 Left Mouse Button

                 The left mouse button, while the cursor is in the sky
            display area, is used for the following functions.

            a)   Select an object
                 Select an object
                 Select an object - if the left mouse button is pressed
                 (and released) within a few pixels of the center of an
                 object, a dialog box, called the "Identify Object"
                 dialog box, will appear identifying and describing the


                                         10





                 object.  Section 5. details the contents of the
                 "Identify Object" dialog box.  A cross-hair will appear
                 on the screen identifying the object currently
                 selected.  The dialog box is always placed in the
                 diagonally opposite corner from the object selected, so
                 that it doesn't cover the object selected.  The dialog
                 box can, of course, be moved about the screen as the
                 user wishes.

                      If more than one object is in the vicinity, the
                 "Next" button can be pressed to update the dialog box
                 with new information for the next object.

                      The dialog box can be terminated in four ways.  If
                 the "Quit" button is pressed, the dialog box will
                 terminate immediately.  If another object is selected,
                 the current dialog box will be replaced with a new one.
                 If the left mouse button is pressed while the cursor is
                 not near an object, the dialog box will terminate.
                 Finally, the <ESC> key can be pressed.

            b)   Zoom a window
                 Zoom a window
                 Zoom a window - the second function performed by the
                 left mouse button is its ability to draw a rectangle on
                 the screen which is used to re-position and re-scale
                 the sky display.  The rectangle is drawn by positioning
                 the mouse at one corner, dragging the mouse (with the
                 left mouse button pressed) to another corner, and then
                 releasing the button.  The center of the rectangle
                 defines the new display center and the vertical height
                 is used to scale the display.


            2.3.1 Right Mouse Button
            2.3.1 Right Mouse Button
            2.3.1 Right Mouse Button

                 The right mouse button, while the cursor is in the sky
            display area, is used for the following functions.

            a)   Center the mouse position
                 Center the mouse position
                 Center the mouse position - if the right mouse button
                 is pressed (and released), the current mouse position
                 will become the center of the sky display at the
                 current scale.  This feature is very useful for quickly
                 "panning" about the sky.

            b)   Measure an angle
                 Measure an angle
                 Measure an angle - the second function performed by the
                 right mouse button is its ability to measure angles on
                 the sky.  Angles are measured by positioning the mouse
                 at one location, dragging the mouse (with the right
                 mouse button pressed) to another location, and then
                 releasing the button.  A dialog box will appear which
                 displays the angular measure between the two points in
                 degrees.


            2.4 On-Screen Controls
            2.4 On-Screen Controls
            2.4 On-Screen Controls


                                         11






                 The on-screen controls include the scroll bars, zoom
            buttons, check boxes, and time step arrows and buttons.
            Each is described below:

            a)   Scroll Bars
                 Scroll Bars
                 Scroll Bars - Two scroll bars are used to rapidly move
                 the center of the sky display about the celestial
                 sphere.  The vertical bar is used to change the
                 Declination.  +90 degrees is at the top; -90 degrees is
                 at the bottom.  Pressing the end arrows will move the
                 pointer (and the sky display) by one degree and
                 pressing along the bar will move the pointer by 10
                 degrees.  The horizontal bar is used to change the
                 Right Ascension.  23 hours 59 minutes is at the left; 0
                 hours is at the right.  Pressing the end arrows will
                 move the pointer by 4 minutes and pressing along the
                 bar will move the pointer by one hour.  When sliding
                 the scroll bars by dragging the pointer, observe at the
                 Right Ascension and Declination displays to know when
                 to stop.

            b)   Zoom buttons
                 Zoom buttons
                 Zoom buttons - the zoom buttons, identified as "zoom
                 in" and "zoom out", are used to change the scale of the
                 sky display.  Each press of the respective button
                 changes the scale by a factor of two.

            c)   Check boxes
                 Check boxes
                 Check boxes - the six check boxes: Stars, Deep Sky,
                 Solar System, Grid, Lines, and Labels are used to
                 toggle whether the respective item is displayed in the
                 sky display.

            d)   Time step arrows and buttons
                 Time step arrows and buttons
                 Time step arrows and buttons - the time buttons "+" and
                 "-" are used to change the current time by the amount
                 shown at the immediate left.  Pressing the black arrows
                 causes the amount at which the time changes to be
                 altered in steps from a minimum of 1 minute to a
                 maximum of 4 years.


            3. Menu Selections
            3. Menu Selections
            3. Menu Selections

                 The menu selections control most of the features of ECU
            and are divided into seven categories as listed below.  Each
            is described in detail in the identified sections:

            a)   File
                 File
                 File - the file menu handles the loading and saving of
                 the configuration settings of ECU (see section 3.1).

            b)   Edit
                 Edit
                 Edit - edit allows the last operation to be nullified
                 (see section 3.2).

            c)   Set
                 Set
                 Set - the set menu allows the time, geographic
                 location, sky display color, comet orbits, and
                 calculation settings to be adjusted (see section 3.3).


                                         12






            d)   Field
                 Field
                 Field - the field menu controls if and how the stars,
                 deep sky objects, planets, sun/moon, grid, lines, and
                 labels are displayed.  It also allows for a full "zoom
                 in" or "zoom out" (see section 3.4).

            e)   Center
                 Center
                 Center - the center menu allows many ways to set the
                 center of the sky display.  These ways include
                 centering on a specified Right Ascension/Declination, a
                 constellation, a bright star, a Messier object, a Solar
                 System object, a point on the local horizon, or by a
                 text search of the databases (see section 3.5).

            f)   Animation
                 Animation
                 Animation - the animation menu controls the various
                 features of the animation mode (see section 3.6).

            g)   About
                 About
                 About - the about menu lists the program credits, the
                 version number, etc. (see section 3.7).
             
                 Many of the common menu items have "short cut" keyboard
            keys to allow quick access to their features.  The keys used
            are identified by an _________
                                 underline under the key used.  The Alt
            key is to be pressed in conjunction with the identified key.
            Also, some menu items identify their keyboard equivalent to
            the right in their menu item.


            3.1 File Menu
            3.1 File Menu
            3.1 File Menu

                 The File
                     File
                     File menu allows the configuration settings of ECU
            to be loaded (opened) and saved.  Virtually every setting in
            ECU is stored in the configuration file.  This allows ECU to
            be "set up" for a particular astronomical event and this
            event saved to a configuration file for later quick
            retrieval.


            3.1.1 Open...
            3.1.1 Open...
            3.1.1 Open...

                 The Open...
                     Open...
                     Open... menu selection presents a dialog box
            allowing a new configuration file selected, then
            subsequently loaded.  It defaults to file names with the
            extension ".cfg".  I will not detail the operation of this
            dialog box, since it is identical to every other MS-Windows
            application that has an Open... function.


            3.1.2 Save
            3.1.2 Save
            3.1.2 Save

                 The Save
                     Save
                     Save menu selection saves the current configuration
            settings to the current configuration file name.  The
            current file name is always displayed on the ECU Window
            title.



                                         13





            3.1.3 Save As...
            3.1.3 Save As...
            3.1.3 Save As...

                 The Save As...
                     Save As...
                     Save As... menu selection saves the current
            configuration settings to the file specified by the file
            name selected in the dialog box presented.  I will not
            detail the operation of this dialog box, since it is
            identical to every other MS-Windows application that has a
            Save As... function.


            3.1.4 Exit
            3.1.4 Exit
            3.1.4 Exit

                 The Exit
                     Exit
                     Exit menu selection is used to exit ECU.  If the
            configuration settings have changed, a message box appears
            ensuring that the user wishes to exit without saving.

                 ECU can also be exited by "double-clicking" on the
            Control-menu box or by selecting "Close" in the window's
            system menu.


            3.2 Edit Menu
            3.2 Edit Menu
            3.2 Edit Menu

                 The Edit
                     Edit
                     Edit menu currently has only one entry: Undo
                                                             Undo
                                                             Undo.  The
            Undo menu selection nullifies the last operation.  This is
            very useful when you have made a "slip of the mouse" and
            wish to get back to where you were.


            3.3 Set Menu
            3.3 Set Menu
            3.3 Set Menu

                 The Set
                     Set
                     Set menu allows the time, geographic location,
            Solar System calculation settings, comet orbits, and sky
            background color to be adjusted.  Each is described in the
            sections below.


            3.3.1 Time
            3.3.1 Time
            3.3.1 Time

                 The time can be set in one of three formats: local
            civil time, Universal time (GMT), or set to your pc's system
            clock (using local civil time).  The current time format
            used is identified in the Time
                                      Time
                                      Time menu selections sub-menu, by
            a check mark in front of the current mode.  The following
            sections describe the time settings.


            3.3.1.1 Enter Local Time
            3.3.1.1 Enter Local Time
            3.3.1.1 Enter Local Time

                 The Enter Local Time
                     Enter Local Time
                     Enter Local Time menu selection presents a dialog
            box allowing the user to enter the year, month, date, hour,
            and minute in local time format.  The year can be from 1000
            to 3000 AD and the hour must be in 24 hour format.  The time
            is always initialized to the current time.


                                         14






                 Ending the dialog box is accomplished by pressing the
            'OK' button.  Aborting, without changing the time, is
            accomplished by pressing 'Cancel'.  If an error is detected
            when ending the dialog box, a 'beep' will sound and the
            cursor will be placed at the offending field.


            3.3.1.2 Enter Universal Time
            3.3.1.2 Enter Universal Time
            3.3.1.2 Enter Universal Time

                 Entering the Universal time is accomplished identically
            to entering the local time.


            3.3.1.3 Use System Time
            3.3.1.3 Use System Time
            3.3.1.3 Use System Time

                 Selecting Use System Time
                           Use System Time
                           Use System Time causes ECU's time base to
            become synched to the pc's system clock.  This will cause
            the sky to update automatically once per minute, therefore
            simulating the actual sky's movements.

            3.3.1.4 Local Time Format
            3.3.1.4 Local Time Format
            3.3.1.4 Local Time Format

                 The local mean time (LMT) display in the status area is
            displayed in either 24 hour or am/pm format.  The Local Time
                                                              Local Time
                                                              Local Time
            Format
            Format
            Format menu selection is a sub-menu of AM/PM
                                                   AM/PM
                                                   AM/PM and 24 Hour
                                                             24 Hour
                                                             24 Hour
            selections, each selection setting the respective format.
            The current format is identified by a 'check mark'.


            3.3.1.5 Daylight Savings
            3.3.1.5 Daylight Savings
            3.3.1.5 Daylight Savings

                 The Daylight Savings
                     Daylight Savings
                     Daylight Savings menu selection toggles whether the
            current local time is to be interpreted as a daylight
            savings time.  It is used by ECU to convert from local time
            to Universal time.  If a 'check mark' is present, daylight
            savings mode is enabled.


            3.3.2 Geographic Location
            3.3.2 Geographic Location
            3.3.2 Geographic Location

                 The Geographic Location
                     Geographic Location
                     Geographic Location menu selection provides a sub-
            menu containing two methods of entering a location on the
            Earth's surface.  These are By Latitude/Longitude
                                        By Latitude/Longitude
                                        By Latitude/Longitude and By
                                                                  By
                                                                  By
            City/Town
            City/Town
            City/Town.


            3.3.2.1 By Latitude/Longitude
            3.3.2.1 By Latitude/Longitude
            3.3.2.1 By Latitude/Longitude

                 The By Latitude/Longitude
                     By Latitude/Longitude
                     By Latitude/Longitude menu selection presents a
            dialog box allowing the user to enter the latitude,
            longitude, and time zone of the location used in the sky
            display calculations.  The latitude is entered as degrees
            (North is positive, South is negative) and minutes.  The


                                         15





            longitude is also entered as degrees (West of the prime
            meridian is positive, East is negative) and minutes.  The
            time zone is entered in hours West of GMT (enter a negative
            for the Eastern hemisphere).  The location is always
            initialized to the current location.

                 Ending the dialog box is accomplished by pressing the
            'OK' button.  Aborting, without changing the location, is
            accomplished by pressing 'Cancel'.  If an error is detected
            when ending the dialog box, a 'beep' will sound and the
            cursor will be placed at the offending field.


            3.3.2.2 By City/Town
            3.3.2.2 By City/Town
            3.3.2.2 By City/Town

                 The By City/Town
                     By City/Town
                     By City/Town menu selection presents a dialog box
            allowing the user to select the location from a set of pre-
            defined locations.  A list box is presented containing the
            available list.  The user is to select the desired location,
            then exit the dialog box.

                 Ending the dialog box is accomplished by pressing the
            'OK' button.  Aborting, without changing the location, is
            accomplished by pressing 'Cancel'.

                 If your location is not in the list of available
            locations, you can use a text editor (the Windows NotePad
                                                              NotePad
                                                              NotePad
            will do fine) to edit the file LOCATION.ECU.  The file
            format is quite simple, as shown by the sample entries
            below:

            49.0 59.0 3.5 Corner Brook NFLD
            53.3 60.1 4 Goose Bay, LAB
            47.5 52.9 3.5 St. John's NFLD
            46.1 59.8 4 Sydney NS

                 The first three entries, which are separated by spaces,
            are the latitude (decimal degrees North of the Equator),
            longitude (decimal degrees West of the Prime meridian), and
            time zone (hours West of GMT).  The fourth entry is the name
            of the location.  The order of lines in the file does not
            matter since ECU sorts the file in order when it is loaded.


            3.3.3 Solar System
            3.3.3 Solar System
            3.3.3 Solar System

                 The Solar System menu selection provides a sub-menu
            allowing several calculation options pertaining to the Solar
            System to be changed.  A 'check mark' in front of a menu
            item indicates that it is enabled.  Each menu item is
            described below.


            3.3.3.1 High Accuracy Calculations
            3.3.3.1 High Accuracy Calculations
            3.3.3.1 High Accuracy Calculations


                                         16






                 This menu selection controls the precision of the solar
            system calculations.  The high accuracy calculations are not
            available when using the SHAREWARE VERSION of ECU.


            3.3.3.2 Precess to Sky Display
            3.3.3.2 Precess to Sky Display
            3.3.3.2 Precess to Sky Display

                 This menu selection controls whether the Solar System
            object positions and the horizon line are to be adjusted
            (due to the effect of precession of the Earth's axis of
            rotation) to match the J2000.0 coordinates used by the sky
            display.


            3.3.3.3 Nutation
            3.3.3.3 Nutation
            3.3.3.3 Nutation

                 This menu selection controls whether the Solar System
            object positions (except the comets) are to be corrected for
            the effects of Nutation.  Nutation is at maximum, a 9 arc-
            second wobble in the precession circle primarily caused by
            the gravitational pull of the Moon.

                 Nutation can only be calculated when the High Accuracy
            Calculations selection is enabled.


            3.3.3.4 Aberration
            3.3.3.4 Aberration
            3.3.3.4 Aberration

                 This menu selection controls whether the Solar System
            object positions (except the comets) are to be corrected for
            the effects of Aberration.  Aberration is the apparent
            displacement of the position of an object due to the finite
            speed of light (whatever that means?).

                 Aberration can only be calculated when the High
            Accuracy selection is enabled.


            3.3.3.5 Light Travel Time
            3.3.3.5 Light Travel Time
            3.3.3.5 Light Travel Time

                 This menu selection controls whether the Solar System
            object positions (except the Moon) are to be corrected for
            the effects of the Light Travel Time.  The Light Travel Time
            correction recognizes that the observer sees an object at
            where it used to be in the past.

                 Light Travel Time corrections can only be calculated
            when the High Accuracy selection is enabled.


            3.3.3.6 Observer's Parallax
            3.3.3.6 Observer's Parallax
            3.3.3.6 Observer's Parallax




                                         17





                 This menu selection controls whether the Solar System
            object positions (except the comets) are to be corrected for
            the effects of the Observer's Parallax.  The Observer's
            Parallax is the effort of an apparent shift of an objects
            position for observers located at different locations on the
            Earth.  This effect is what causes the Solar Eclipses and
            Occultations of the Moon to be only observable from certain
            locations on the Earth's surface.  Be sure to enable this
            selection when simulating events which are location specific
            like solar eclipses.


            3.3.4 Define Comet Orbit
            3.3.4 Define Comet Orbit
            3.3.4 Define Comet Orbit

                 The Define Comet Orbit
                     Define Comet Orbit
                     Define Comet Orbit menu selection provides a sub-
            menu of the four comets which can be defined.  Each
            selection is identical except for the comet number.

                 Each sub-menu selection presents a dialog box allowing
            the orbital elements of a comet to be entered.  The
            following items can be entered.

            a)   Comet Name - a textual name that can be displayed next
                 to the comet in the sky display.
            b)   Date of Perihelion - the date of perihelion can be
                 entered as either decimal years or as year, month, and
                 decimal days.  If the month is set to zero, the decimal
                 years are used and the month and date are ignored.  If
                 the month is valid (1 to 12), the year, month, and date
                 are used.
            c)   Perihelion Distance - the distance of the comet to the
                 Sun in astronomical units (AU) at Perihelion.
            d)   Eccentricity - the eccentricity of the comet's orbit
                 from 0 to 1.
            e)   Longitude of Perihelion - the longitude, in degrees, of
                 the perihelion.
            f)   Longitude of Ascending Node - the longitude, in
                 degrees, of the ascending node.
            g)   Inclination of Orbit - the inclination of the orbit in
                 degrees.
            h)   Epoch of the Elements - the epoch of the elements,
                 either B1950.0 or J2000.0.
            i)   Magnitude Constants - the magnitude constants g and k,
                 are used to estimate the brightness of the comet.  Each
                 comet has a different set of constants.  Comet
                 brightness predictions are notoriously extremely
                 unreliable.
            g)   Enable Comet - this flag enables the comet for display.

                 Ending the dialog box is accomplished by pressing the
            'OK' button.  Aborting, without changing the comet orbital
            elements, is accomplished by pressing 'Cancel'.




                                         18





            3.3.5 Sky Background Color
            3.3.5 Sky Background Color
            3.3.5 Sky Background Color

                 The Sky Background Color
                     Sky Background Color
                     Sky Background Color menu selection provides a sub-
            menu allowing the sky background to be set to either black
            or white.  I find the black background more pleasing, but
            the white background is required for printing of sky charts.
            The current mode is identified by the 'check mark'.


            3.4 Field Menu
            3.4 Field Menu
            3.4 Field Menu

                 The Field
                     Field
                     Field menu controls various parameters pertaining
            to the sky display.  Each menu selection is described
            separately in the following sections.


            3.4.1 Magnitude Limits...
            3.4.1 Magnitude Limits...
            3.4.1 Magnitude Limits...

                 The Magnitude Limits...
                     Magnitude Limits...
                     Magnitude Limits... menu selection presents a
            dialog box allowing the user to set the limiting magnitude
            for stellar and deep sky objects.  The magnitude is set by
            dragging the scroll bars to the desired magnitude as
            displayed immediately below each scroll bar.

                 The actual stellar limiting magnitude is dependant on
            the field size, however, the setting here sets the upper
            limit.  If the deep sky magnitude limit is set to 20, all
            objects will be displayed, even those whose magnitude is
            unknown.

                 Pressing 'OK' exits the dialog box and activates the
            new magnitude limits.  Pressing 'Cancel' exits without
            making any changes.


            3.4.2 Object Selection...
            3.4.2 Object Selection...
            3.4.2 Object Selection...

                 The Object Selection...
                     Object Selection...
                     Object Selection... menu selection presents a
            dialog box allowing the user to select which types of deep
            sky objects are displayed.  The dialog box has 7 check
            boxes; one for each of Galaxies, Globular Clusters, Open
            Clusters, Bright Nebulae, Planetary Nebulae, Other, and
            Unknown Magnitudes.  If the check box of the respective
            object type is true, that type will be displayed (if deep
            sky objects are also 'turned on').

                 Note that the 'Unknown Magnitude' type allows for the
            display of objects whose magnitude is unknown, without
            littering the display with hundreds (or thousands) of faint
            objects, as would be the case if the limiting magnitude were
            set to 20 as described in Section 3.4.1.





                                         19





                 Pressing 'OK' exits the dialog box and activates the
            new object selections.  Pressing 'Cancel' exits without
            making any changes.


            3.4.3 Planets...
            3.4.3 Planets...
            3.4.3 Planets...

                 The Planets...
                     Planets...
                     Planets... menu selection presents a dialog box
            which allows the user to control various display parameters
            for the eight planets.  The three entries for each planet
            include a check box indicating if the respective planet is
            displayed, a set of radio buttons which determines if it is
            displayed as either a point or as the planet's symbol, and a
            check box indicating if the planet's name is also displayed.

                 Pressing 'OK' exits the dialog box and activates the
            new planets settings.  Pressing 'Cancel' exits without
            making any changes.


            3.4.4 Sun
            3.4.4 Sun
            3.4.4 Sun

                 The Sun
                     Sun
                     Sun menu selection toggles whether or not the Sun
            is displayed on the sky display.  If marked by a 'check
            mark', the Sun will be displayed (assuming the Solar System
            objects are also 'turned on').


            3.4.5 Moon
            3.4.5 Moon
            3.4.5 Moon

                 The Moon
                     Moon
                     Moon menu selection toggles whether or not the Moon
            is displayed on the sky display.  If marked by a 'check
            mark', the Moon will be displayed (assuming the Solar System
            objects are also 'turned on').


            3.4.6 Grid
            3.4.6 Grid
            3.4.6 Grid

                 The Grid
                     Grid
                     Grid menu selection provides a sub-menu allowing
            the resolution of the coordinate grid to be set.  If 'Fine'
            is selected, the grid will mark every 20 minutes in Right
            Ascension and every 5 degrees in Declination.  If 'Course'
            is selected, the grid will mark every 1 hour in Right
            Ascension and every 10 degrees in Declination.  A 'check
            mark' marks the current setting.


            3.4.7 Lines/Points
            3.4.7 Lines/Points
            3.4.7 Lines/Points

                 The Lines/Points
                     Lines/Points
                     Lines/Points menu selection provides a sub-menu
            allowing the user to toggle the display of lines and points
            on the sky display.  These include the constellation lines,
            ecliptic line, horizon line, zenith point, and celestial



                                         20





            pole points.  The current state of each line/point is
            indicated by a 'check mark' in front of the menu item.


            3.4.8 Labels
            3.4.8 Labels
            3.4.8 Labels

                 The Labels
                     Labels
                     Labels menu selection provides a sub-menu allowing
            the user to toggle the display of text labels on the sky
            display.  These include the constellation labels, bright
            star labels, Solar System labels, Messier labels, horizon
            line/zenith point labels (N,S,E,W, etc.), and ecliptic point
            labels (VE - vernal equinox, SS - summer solstice, etc.).
            The current state of each label is indicated by a 'check
            mark' in front of the menu item.


            3.4.9 Zoom In Full
            3.4.9 Zoom In Full
            3.4.9 Zoom In Full

                 The Zoom In Full
                     Zoom In Full
                     Zoom In Full menu selection causes the ECU sky
            display to zoom in to the minimum allowable field size,
            which is 1 degree in height.


            3.4.10 Zoom Out Full
            3.4.10 Zoom Out Full
            3.4.10 Zoom Out Full

                 The Zoom Out Full
                     Zoom Out Full
                     Zoom Out Full menu selection causes the ECU sky
            display to zoom out to the maximum allowable field size,
            which is about 60 degrees in height.


            3.5 Center Menu
            3.5 Center Menu
            3.5 Center Menu

                 The Center
                     Center
                     Center menu allows the user to quickly center on
            most objects in ECU's databases.  This includes centering on
            a specified Right Ascension/Declination, a constellation, a
            bright star, Messier object, Solar System object, a point on
            the local horizon, or on a text search of the databases.
            When an object is centered on the sky display, a cross-hair
            is used to mark it.  Each centering menu selection is
            described separately below.


            3.5.1 On RA/Dec...
            3.5.1 On RA/Dec...
            3.5.1 On RA/Dec...

                 The On RA/Dec...
                     On RA/Dec...
                     On RA/Dec... menu selection presents a dialog box
            allowing the user enter a specific Right Ascension and
            Declination to center the sky display on.  The Right
            Ascension is entered as hours and minutes.  The Declination
            is entered as degrees and minutes.

                 Ending the dialog box is accomplished by pressing the
            'OK' button.  Aborting, without changing the sky display, is
            accomplished by pressing 'Cancel'.  If an error is detected



                                         21





            when ending the dialog box, a 'beep' will sound and the
            cursor will be placed at the offending field.

                 When the dialog box ends, ECU centers the sky display
            at the coordinates entered.


            3.5.2 On Constellation...
            3.5.2 On Constellation...
            3.5.2 On Constellation...

                 The On Constellation...
                     On Constellation...
                     On Constellation... menu selection presents a
            dialog box allowing the user to select a constellation to
            center the sky display on.  A list box is presented
            containing the available list of 88 constellations in
            alphabetical order.  The user is to select the desired
            constellation, then exit the dialog box.  ECU then centers
            the sky display on the selected constellation.


            3.5.3 On Bright Star...
            3.5.3 On Bright Star...
            3.5.3 On Bright Star...

                 The On Bright Star...
                     On Bright Star...
                     On Bright Star... menu selection presents a dialog
            box allowing the user to select a bright star to center the
            sky display on.  A list box is presented containing the
            available list of bright stars in alphabetical order.  The
            user is to select the desired bright star, then exit the
            dialog box.  ECU then centers the sky display on the
            selected bright star.


            3.5.4 On Messier Object...
            3.5.4 On Messier Object...
            3.5.4 On Messier Object...

                 The On Messier Object...
                     On Messier Object...
                     On Messier Object... menu selection presents a
            dialog box allowing the user to select a Messier Object to
            center the sky display on.  A list box is presented
            containing the available list of 110 Messier objects in
            numerical order.  The user is to select the desired object,
            then exit the dialog box.  ECU then centers the sky display
            on the selected Messier object.


            3.5.5 On Solar System Object
            3.5.5 On Solar System Object
            3.5.5 On Solar System Object

                 The On Solar System Object
                     On Solar System Object
                     On Solar System Object menu selection contains a
            sub-menu of all the Solar System objects (Sun, Moon,
            Planets, and Comets).  The menu item selected is centered on
            the sky display.


            3.5.6 On Point on Horizon
            3.5.6 On Point on Horizon
            3.5.6 On Point on Horizon

                 The On Point on Horizon
                     On Point on Horizon
                     On Point on Horizon menu selection contains a sub-
            menu of all the cardinal points on the local horizon plus
            the Zenith (the overhead point).  The menu item selected
            becomes centered on the sky display.


                                         22







            3.5.7 On Database Search...
            3.5.7 On Database Search...
            3.5.7 On Database Search...

                 The On Database Search...
                     On Database Search...
                     On Database Search... menu selection is used to
            search the ECU databases for a specified object.  If a match
            is found, the specified object is centered on the sky
            display.  The user is presented with a dialog box which
            prompts for a line of text.  If the 'OK' button is pressed,
            the search commences.  The line of text entered is
            immediately converted to upper case to avoid ambiguities and
            all spaces are removed.  The object types which can be
            searched for are listed below:

            a)   Constellations - the 88 constellations can be searched
                 by entering their complete formal name (eg. 'Ursa
                 Major').
            b)   Bright Stars - bright stars can be searched by entering
                 their complete formal name (eg. 'Deneb').
            c)   Stars - any star in the database can be searched by
                 entering its Smithsonian Astrophysical Observatory
                 (SAO) catalog number with the prefix 'SAO'.  For
                 example, to find the SAO star number 49898, enter
                 'SAO49898'.  Note that entering 'sao  49898' would be
                 just as effective because the case of the input and
                 spaces are ignored.  Searching for SAO stars is not
                 available in the SHAREWARE VERSION of ECU.
            d)   Deep Sky Objects - deep sky objects can be searched by
                 entering either their primary name or 'Other Names:' as
                 stored in the SAC deep sky database (see Section 4.).
                 For example, the Andromeda Galaxy can be found by
                 entering either its official name 'NGC224' or its
                 common name (other name) 'M31'.  Searching for deep sky
                 objects is not available in the SHAREWARE VERSION of
                 ECU.

                 If the search is not successful, a message box will
            appear informing the user of this.


            3.6 Animation Menu
            3.6 Animation Menu
            3.6 Animation Menu

                 The Animation
                     Animation
                     Animation menu controls all of the functions of
            ECU's animation mode.  The animation mode is used to
            simulate astronomical events which are affected by changes
            in the time.  The animation mode has the following features.

            a)   Time can be automatically stepped in any step from 1
                 minute to 4 years.
            b)   Time can be stepped in either forward or reverse.
            c)   The time between time steps can be set from 0 to 60
                 seconds.
            d)   The solar system objects can be trailed with dots drawn
                 behind them.


                                         23





            e)   The number of dots used in the trail can be set from 10
                 to 255.
            e)   The sky display can be made to 'lock' on any solar
                 system object, or point with reference to the local
                 horizon.
            f)   The time can be manually stepped, either forward or in
                 reverse.
            g)   All of the features of ECU can be used while the
                 animation mode is running due to the multi-tasking
                 nature of Windows, and thus of ECU.

                 Animation mode is best learned by experimentation,
            however, the menu items which control the animation mode are
            described in the sections below.


            3.6.1 Start
            3.6.1 Start
            3.6.1 Start

                 The Start
                     Start
                     Start menu selection starts the animation mode.  If
            a 'check mark' preceeds the menu selection, animation mode
            is running.

            3.6.2 Stop
            3.6.2 Stop
            3.6.2 Stop

                 The Stop
                     Stop
                     Stop menu selection stops the animation mode.  The
            ESC key can also be used to stop the animation mode.


            3.6.3 Forward One Step
            3.6.3 Forward One Step
            3.6.3 Forward One Step

                 The Forward One Step
                     Forward One Step
                     Forward One Step menu selection steps the time
            forward by one time step.  The time step is displayed to the
            left of the time step buttons in the status area.  This menu
            selection can also be executed by pressing the '+' key or
            the '+' button.


            3.6.4 Reverse One Step
            3.6.4 Reverse One Step
            3.6.4 Reverse One Step

                 The Reverse One Step
                     Reverse One Step
                     Reverse One Step menu selection steps the time in
            reverse by one time step.  The time step is displayed to the
            left of the time step buttons in the status area.  This menu
            selection can also be executed by pressing the '-' key or
            the '-' button.


            3.6.5 Trails On
            3.6.5 Trails On
            3.6.5 Trails On

                 The Trails On
                     Trails On
                     Trails On menu selection enables the drawing of
            trails behind the Solar System objects.  If the trails are
            enabled, a 'check mark' will preceed this menu selection.


            3.6.6 Maximum Trails...
            3.6.6 Maximum Trails...
            3.6.6 Maximum Trails...


                                         24






                 The Maximum Trails...
                     Maximum Trails...
                     Maximum Trails... menu selection presents a dialog
            box allowing the user to enter the number of trails (10 to
            255) to be drawn behind Solar System Objects.

                 Ending the dialog box is accomplished by pressing the
            'OK' button.  Aborting, without changing, is accomplished by
            pressing 'Cancel'.  If an error is detected when ending the
            dialog box, a 'beep' will sound and the cursor will be
            placed at the offending field.


            3.6.7 Lock On Current RA/Dec
            3.6.7 Lock On Current RA/Dec
            3.6.7 Lock On Current RA/Dec

                 The Lock On Current RA/Dec
                     Lock On Current RA/Dec
                     Lock On Current RA/Dec menu selection causes the
            animation mode to be locked on the current Right Ascension
            and Declination.  In fact, it turns 'lock mode' off.  If
            locked on the current RA/Dec, a 'check mark' will
            immediately preceed this menu selection.


            3.6.8 Lock On Current Azim/Alt
            3.6.8 Lock On Current Azim/Alt
            3.6.8 Lock On Current Azim/Alt

                 The Lock On Current Azim/Alt
                     Lock On Current Azim/Alt
                     Lock On Current Azim/Alt menu selection causes the
            animation mode to be locked on the current altitude and
            azimuth, with respect to the local horizon.  This feature is
            very useful for 'watching' a particular horizon as the
            constellations rise or set, or as a planet such as Mercury
            crests above the horizon.  If locked on the current
            Azim/Alt, a 'check mark' will immediately preceed this menu
            selection.


            3.6.9 Lock On Solar System Object
            3.6.9 Lock On Solar System Object
            3.6.9 Lock On Solar System Object

                 The Lock On Solar System Object
                     Lock On Solar System Object
                     Lock On Solar System Object menu selection presents
            a sub-menu of all the Solar System objects (Sun, Moon,
            Planets, and Comets).  The menu item selected becomes locked
            to the center of the sky display in animation mode.  A
            'check mark' will immediately preceed the Solar System
            object locked.


            3.6.10 Time Direction
            3.6.10 Time Direction
            3.6.10 Time Direction

                 The Time Direction
                     Time Direction
                     Time Direction menu selection presents a sub-menu
            of the selections: Forward
                               Forward
                               Forward and Reverse
                                           Reverse
                                           Reverse.  These selections
            control the direction in which time is stepped when the
            animation mode is running.  A 'check mark' will immediately
            preceed the time direction setting.


            3.6.11 Time Step
            3.6.11 Time Step
            3.6.11 Time Step



                                         25





                 The Time Step
                     Time Step
                     Time Step menu selection presents a sub-menu of the
            selections: Increase
                        Increase
                        Increase and Decrease
                                     Decrease
                                     Decrease.  These selections
            increase or decrease, by one notch, the amount of the
            animation mode time step.  The current time step is shown as
            the third sub-menu item.  These two selections are
            duplicates of the time step arrows in the status area.


            3.6.12 Animation Speed...
            3.6.12 Animation Speed...
            3.6.12 Animation Speed...

                 The Animation Speed...
                     Animation Speed...
                     Animation Speed... menu selection presents a dialog
            box allowing the user enter the number of seconds between
            animation mode updates (0 to 60 seconds).

                 Ending the dialog box is accomplished by pressing the
            'OK' button.  Aborting, without changing, is accomplished by
            pressing 'Cancel'.  If an error is detected when ending the
            dialog box, a 'beep' will sound and the cursor will be
            placed at the offending field.


            3.7 About Menu
            3.7 About Menu
            3.7 About Menu

                 The About
                     About
                     About menu has two entries.  The first selection,
            ECU...
            ECU...
            ECU..., presents a message box identifying ECU, its version
            number, its copyright notice, and how to contact the author.

                 The second selection, Willman-Bell...
                                       Willman-Bell...
                                       Willman-Bell..., presents a
            message box identifying that ECU contains source code that
            which is copyrighted by Jeffrey Sax.  The source code
            referred to, provides high accuracy astronomical
            calculations based on the algorithms described in the book:
            Astronomical Algorithms by Jean Meuss
            Astronomical Algorithms by Jean Meuss
            Astronomical Algorithms by Jean Meuss (distributed by
            Willman-Bell).  The message given in the message box is a
            requirement of distributing programs containing Jeffrey's
            source code.


            4. Databases
            4. Databases
            4. Databases

                 This section will describe the databases built-in to
            ECU.  ECU contains several databases.  The databases which
            will be covered in this section are the stellar database and
            the deep sky database.  Other databases include the label,
            constellation line, and geographic location databases.


            4.1 Stellar Database
            4.1 Stellar Database
            4.1 Stellar Database

                 The stellar database (files SAO1.ECU and SAO2.ECU) is a
            sub-set of the Smithsonian Astrophysical Observatory (SAO)
            Star Catalog.  The entire catalog contains some 260,000
            stars of which ECU uses the brightest 12,155 members of the
            catalog, which includes all stars to magnitude 6.8.


                                         26






                 The database contains the magnitude (visual, if
            available), Right Ascension, Declination, catalog number,
            and spectral classification of each star in the database.
            The Right Ascension and Declination are in J2000.0
            coordinates and are displayed on the sky display using this
            epoch.  The SHAREWARE VERSION of ECU does not know star's
            catalog number or spectral classification.


            4.2 Deep Sky Database
            4.2 Deep Sky Database
            4.2 Deep Sky Database

                 The deep sky database (files SAC1.ECU and SAC2.ECU)
            contains a complete database of 10367 deep sky objects.  The
            members of the Saguaro Astronomy Club (SAC) (pronounced sa-
            war-oh) of Phoenix, Arizona have provided much of the effort
            to compile this database (database version 5.2).  The
            database includes the entire NGC catalog, plus other
            interesting deep sky objects.  Selected fields of the SAC
            database were extracted for use in ECU.  Only the object
            type, magnitude, and position are available with the
            SHAREWARE VERSION of ECU.  These fields are described below:

            a)   Object Name - usually the NGC number, but for objects
                 with no NGC value, other catalogs are used.  The
                 abbreviations listed below are used to represent the
                 other catalogs.

            Abell - George Abell (planetary nebulae and galaxy clusters)
            AM - Arp-Madore (globular clusters)
            Antalova - (open clusters)
            Bark - Barkhatova (open clusters)
            B - Barnard (dark nebulae)
            Basel - (open clusters)
            Berk - Berkeley (open clusters)
            Be - Bernes (dark nebulae)
            Biur - Biurakan (open clusters)
            Blanco - (open clusters)
            Bochum - (open clusters)
            Ced - Cederblad (bright nebulae)
            Cr - Collinder (open clusters)
            Czernik - (open clusters)
            Do - Dolidze (open clusters)
            DoDz - Dolidze-Dzimselejsvili (open clusters)
            Dun - Dunlop (globular clusters)
            Fein - Feinstein (open clusters)
            Frolov - (open clusters)
            Gum - (bright nebulae)
            H - William Herschel (globular clusters)
            Haffner - (open clusters)
            Harvard - (open clusters)
            He - Henize (planetary nebulae)
            Hogg - (open clusters)
            HP - Haute Provence (globular clusters)


                                         27





            Hu - Humason (planetary nebulae)
            IC - 1st and 2nd Index Catalogs to the NGC
                 (All types of objects except dark nebulae)
            Isk - Iskudarian (open clusters)
            J - Jonckheere (planetary nebulae)
            K - Kohoutek (planetary nebulae)
            King - (open clusters)
            Lac - Lacaille (globular clusters)
            Loden - (open clusters)
            LDN - Lynds (dark nebulae)
            Lynga - (open clusters)
            M - Messier (all types of objects except dark nebula)
            Mrk - Markarian (open clusters and galaxies)
            Mel - Melotte (open clusters)
            M1 - Minkowski (planetary nebulae)
            NGC - New General Catalog of Nebulae & Clusters of Stars.
                  (All types of objects except dark nebulae)
            Pal - Palomar (globular clusters)
            Pismis - (open clusters)
            PK - Perek & Kohoutek (planetary nebulae)
            RCW - Rodgers, Campbell, & Whiteoak (bright nebulae)
            Roslund - (open clusters)
            Ru - Ruprecht (open clusters)
            Sa - Sandqvist (dark nebulae)
            Sher - (open clusters)
            Sh - Sharpless (bright nebulae)
            SL - Sandqvist & Lindroos (dark nebulae)
            Steph - Stephenson (open clusters)
            Stock - (open clusters)
            Ter - Terzan (globular clusters)
            Tombaugh - (open clusters)
            Ton - Tonantzintla (globular clusters)
            Tr - Trumpler (open clusters)
            UGC - Uppsala General Catalog (galaxies)
            UKS - United Kingdom Schmidt (globular clusters)
            Upgren - (open clusters)
            vdB - van den Bergh (open clusters, bright nebulae)
            vdBH - van den Bergh & Herbst (bright nebulae)
            vdB-Ha - van den Bergh-Hagen (open clusters)
            Vy - Vyssotsky (planetary nebulae)
            Waterloo - (open clusters)
            Westr - Westerlund (open clusters)

            b)   Other Name - contains other catalog designations that
                 the object is known by.  The same abbreviations as in
                 a) are used.

            c)   Object Type - the type of object from the list below.

            Asterism
            Bright Nebula
            Cluster with Nebulosity
            Dark Nebula
            Galaxy cluster


                                         28





            Galaxy
            Globular Cluster
            Diffuse Nebula in a Galaxy
            Globular Cluster in a Galaxy
            Cluster with Nebulosity in a Galaxy
            Cluster with Nebulosity in the LMC
            Diffuse Nebula in the LMC
            Globular Cluster in the LMC
            Open cluster in the LMC
            Nonexistent in RNGC
                 (means Sulentic and Tifft couldn't find it on the POSS
                 plates for inclusion in the RNGC)
            Open Cluster
            Planetary Nebula
            Cluster with Nebulosity in the SMC
            Diffuse Nebula in the SMC
            Globular Cluster in the SMC
            Open cluster in the SMC
            Quasar
            Unverified Southern Object
            Multiple Star

            d)   Position - the object's position, Right Ascension and
                 Declination, in the J2000.0 epoch.

            e)   Magnitude - the object's brightness to the nearest
                 tenth.  There are many objects which have no published
                 magnitude; they are listed as ??.?.  Dark nebulae
                 obviously have no magnitude, so they are also listed as
                 ??.?.

            f)   Description - a visual description of the object.  Most
                 of these are from the NGC, some are from prominent
                 amateurs.  Back issues of Deep Sky Magazine, Astronomy
                 magazine, Sky and Telescope magazine and Burnham's
                 Celestial Handbook are used as a source of some of
                 these descriptions.  The  descriptions use the
                 abbreviations from the NGC and Burnham's.  They are
                 given below:

            !    remarkable object   !!   very remarkable object
            am   among               n    north
            att  attached            N    nucleus
            bet  between             neb  nebula, nebulosity
            B    bright              P w  paired with
            b    brighter            p    pretty (before F,B,L or S)
            C    compressed          p    preceding
            c    considerably        P    poor
            Cl   cluster             R    round
            D    double              Ri   rich
            def  defined             r    not well resolved, mottled
            deg  degrees             rr   partially resolved
            diam diameter            rrr  well resolved
            dif  diffuse             S    small


                                         29





            E    elongated           s    suddenly
            e    extremely           s    south
            er   easily resolved     sc   scattered
            F    faint               susp suspected
            f    following           st   star or stellar
            g    gradually           v    very
            iF   irregular figure    var  variable
            inv  involved            nf   north following
            irr  irregular           np   north preceding
            L    large               sf   south following
            l    little              sp   south preceding
            mag  magnitude           11m  11th magnitude
            M    middle              8... 8th magnitude and fainter
            m    much                9...13 9th to 13th magnitude

            g)   Size - the size of the object in minutes of arc (') or
                 seconds of arc (").

            h)   Class - the class of the object.  Several professional
                 classification schemes are contained here.

            Trumpler type for open clusters
            Trumpler type for open clusters
            Trumpler type for open clusters

            Concentration
            I.   Detached, strong concentration toward the center
            II.  Detached, weak concentration toward the center
            III. Detached, no concentration toward the center
            IV.  Not well detached from surrounding star field

            Range in brightness
            1.  Small 2.  Moderate range  3.  Large range

            Richness
            p  Poor (<50 stars)
            m  Moderately rich (50-100 stars)
            r  Rich (>100 stars)

            An "n" following the Trumpler type denotes nebulosity in
            cluster

            Shapley-Sawyer concentration rating for globular clusters
            Shapley-Sawyer concentration rating for globular clusters
            Shapley-Sawyer concentration rating for globular clusters

            The values range from 1 to 12, smaller numbers are more
            concentrated clusters.

            Vorontsov-Velyaminov type for planetary nebulae
            Vorontsov-Velyaminov type for planetary nebulae
            Vorontsov-Velyaminov type for planetary nebulae

            1.  Stellar
            2.  Smooth disk (a, brighter center; b, uniform brightness;
                c, traces of ring structure)
            3.  Irregular disk (a, very irregular brightness;
                b, traces of ring structure)
            4.  Ring structure
            5.  Irregular form similar to diffuse nebula


                                         30





            6.  Anomalous form, no regular structure

            Some very complex forms may combine two types.

            Hubble type for galaxies
            Hubble type for galaxies
            Hubble type for galaxies

            E  elliptical, E0 is roundest to E7 is flattest
               subgroups; 'd'is dwarf, 'c'is supergiant,
               'D' has diffuse halo
            S  Spiral, 'a' has tightly wound arms, 'b' has moderately
               wound arms and 'c' has loosely wound arms
            SB Spiral with central bar
            Ir Irregular


            5. Identify Objects
            5. Identify Objects
            5. Identify Objects

                 The identify objects dialog box contains various
            information pertaining to the currently selected object.
            The information common to all object types includes the
            Right Ascension and Declination, and the Altitude and
            Azimuth with reference to the local horizon.  Each object
            type is listed below with each one's specific information
            displayed in the identify objects dialog box.

            a)   Sun - the sun's distance, in astronomical units; and
                 its size, in minutes of arc are displayed.

            b)   Moon - the moon's distance from the Earth, in
                 kilometres; its size, in minutes of arc; its age, in
                 days; and its phase are displayed.

            c)   Planets - the planet's magnitude; its distance from the
                 Earth, in astronomical units; its size, in seconds of
                 arc; and its phase (0 to 1) are displayed.

            d)   Comets - the comet's magnitude; and its distance from
                 the Earth and the Sun in astronomical units are
                 displayed.

            e)   Stars - the star's magnitude; and its spectral
                 classification are displayed.

            f)   Deep Sky Objects - the object's magnitude (if known);
                 its primary and other names; its description; its size;
                 and its object class are displayed.  See section 4.2.


            6. Printing Star Charts
            6. Printing Star Charts
            6. Printing Star Charts

                 ECU current does not currently support the direct
            printing of star charts.  However, the SHAREWARE graphics
            program "Paint Shop", produces excellent charts with ECU.
            The procedure that I use is listed below.


                                         31






            a)   Start up Paint Shop.
            b)   Set up ECU as desired in "full screen" mode.
            c)   Switch Sky Background Color to White.
            d)   Use the Control Menu's "Switch To..." selection to
                 Select Paint Shop.
            e)   Use Paint Shop's "Capture" menu to grab ECU's full
                 screen, or part there of.
            f)   Use Paint Shop's "Print" selection to print out the
                 results.


            7. The Future of ECU
            7. The Future of ECU
            7. The Future of ECU

                 The future of ECU depends on you.  If you register it,
            it gives me the signal that you are using it, which will
            give me lots of incentive to improve it (if no one uses it,
            why improve it?).  Below is a partial list of the features
            which are coming in future releases of ECU.

            -  add the position angle into moon phases
            -  add menu times for zoom to 10,20,and 40 degree field
            -  change the deep sky symbols
            -  add rise, set, and transit times to Identify Object mode
            -  add dialog boxes for label and lines settings
            -  add a flag for controlling calculation of atmospheric
               refraction
            -  provide full EGA compatibility
            -  add Dreyer deep sky object description help dialog box
            -  add an observing list output of objects currently on the
               screen
            -  add Earth's shadow for simulating lunar eclipses
            -  add ability to paste the screen to the clipboard
            -  add direct sky chart printing
            -  add planet empheris printer output
            -  add full Smithsonian Astrophysical Observatory (SAO) star
               database (259k stars) integrated with Yale Bright Star
               Catalog
            -  provide more realistic star brightness displays using a
               combination of white/black and greys
            -  add a cross reference from SAO to star names, Flamsteed#,
               and Bayer letter
            -  Hubble Guide Star Catalog CDROM support
            -  add text labels on the coordinate grid
            -  add ability for the user to add objects
            -  add ability to set the colors of nearly everything, plus
               a red mode for dark adaptation in observatory use
            -  allow the user to add descriptions (an observing log) of
               stars and deep sky objects
            -  add display of Jupiter's moons
            -  add display of Saturn's moons/rings
            -  add the SAC double star database support




                                         32






                                  REGISTRATION FORM
                            "The Earth Centered Universe"
                            for Microsoft(R) Windows 3.0
                                        (ECU)
                                SHAREWARE VERSION 1.1
                                 Released March 1992

            NAME: _____________________________________________________

            STREET: ___________________________________________________

            CITY: _____________________________________________________

            PROVINCE/STATE: ___________________________________________

            POSTAL/ZIP CODE: __________________________________________

            TELEPHONE NUMBER (S): _____________________________________

            ECU Registration:   $35US.................... _________

                                $40CDN................... _________

            Optional Complete SAO Star Catalog:
            (available by May 1, 1992)

                                $30US.................... _________

                                $35CDN................... _________

            Minor upgrade:      $10US.................... _________

                                $12CDN................... _________

            Total:         (  ) US or (  ) CDN............ _________

            Disk size:     (  ) 3.5" 1.44M     (  ) 5.25" 1.2M
                           (  ) 3.5" 720K


                 Payment may be made by postal money order or certified
            check (Canadians may use a personal check) to:

                      David Lane
                      4-26 Randall Avenue
                      Halifax, Nova Scotia
                      Canada B3M 1E2

                 Please support the continued improvement of ECU by
            registering it now!





                                         33