Libris Britannia 4/science library(b).zip/science library(b)/ASTRONOM/2935A.ZIP/DS3D1.EXE/TEXT.TXT

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>CATALOG & ORDER FORM

     DAVID CHANDLER CO., P.O. BOX 309, LA VERNE, CA 91750 / [phone]
      (All items authored and published by David Chandler except as noted)
                           (Prices subject to change)

 DEEP SPACE 3-D, Ver 3.0 -- 3-Disk Set with 3-D Viewer
     Single User Registration                          $  79   _____   ______
     Site Registration (Per building)                  $ 159   _____   ______

 UPGRADE from version 2.0, 2.1, or 2.1a                $  25   _____   ______
 UPGRADE from version 1.3 or earlier                   $  30   _____   ______

 LARGE TABLE-TOP 3-D VIEWER KIT                        $  35   _____   ______
     (For viewing pairs of 8-1/2 x 11 printouts in stereo)


 DEEP SPACE 3-D, Ver 3.0 (Unregistered Shareware Copy--2 Disks)
-    (With $15 coupon toward registration price)       $  15   _____   ______

 (Only registered versions of the program can access the additional data files)

 STAR DATABASE FILES--(SST01 through SST06 come with registration)
                                                         (New Reduced Prices)
 SST07 through SST41 (134,053 Stars to Mag 8.9)        $  35   _____   ______
 SST42 through SST77 (248,709 Stars to Mag 10+)        $  35   _____   ______
       (SST07 through SST77 purchased at one time)     $  65   _____   ______


 ORBITAL ELEMENTS FOR OVER 1100 COMETS dating back to 240 BC, based on Brian
-Marsden's "Catalog of Cometary Orbits" (and more)     $ 15    _____   ______

 COMET WATCH--A newsletter giving finder charts and orbital elements that can
     be used with DEEP SPACE 3-D.  15 issues per volume, "Vol 0" gives extra
     background information and lots of data to get started.

                                             Vol 0   $ 10 ea   _____   ______
    _____ Volumes starting with the current Volume   $ 10 ea   _____   ______
   3-D viewer, when ordered with Comet Watch         $  5 ea   _____   ______
-   (Overseas Subscriptions: $ 15 / Viewer: $  5)              _____   ______


                               OTHER IBM SOFTWARE

 PLANETS IN THE CLASSROOM, IBM Version (Not Shareware) -- A program for
     understanding planetary motion, specifically designed for teachers, but of
     interest to amateur astronomers as well.  Comes with a manual of classroom
     exercises appropriate for various levels from elementary through college.
                                                       $  39   _____   ______

 ALGOL, IAU TELEGRAMS, and CELL -- Three special purpose programs.  ALGOL
     computes the dates and times of the minima of the eclipsing binary star
     Algol in local time.  TELEGRAMS takes input from a menu and encodes
     telegrams in the proper format to report discoveries of comets, novas,
     supernovas, etc. to the Center for Astronomical Telegrams.  CELL
     rigorously calculates the parameters for designing 9-point and 18-point
     telescope mirror cells.
                                                       $  10   _____   ______
-

                       BOOKS AND CHARTS by David Chandler

 THE NIGHT SKY / A specially designed low distortion rotating star chart for
     anyone who really wants to get to know the sky.  This practical, take-
     it-out-and-use-it star finder is the real backbone of our product line.
     Over 1/4 million copies are in circulation.  Astronomy educators are its
     most vocal fans:

        "The Night Sky is not just another planisphere.  I think The Night Sky
     is the finest and easiest to use star finding aid in existence."
                     -- Jack Horkheimer, T.V.'s "Star Hustler" and Planetarium
                        Director at the Miami Museum of Science.
                                                      $ 5.95   _____   ______
                              Latitude or nearest large city   ______________

-     (Teachers: Ask for "Sample Classroom Exercises using The Night Sky")

 EXPLORING THE NIGHT SKY WITH BINOCULARS -- (Illustrated by Don Davis)
     A written companion to THE NIGHT SKY that leads the beginner from naked
     eye astronomy to the ideal "first telescope": a pair of binoculars.  It
     covers both what to see and the significance of what is seen.  This book
     was written with adults in mind, but it received honorable mention in the
     Older Children's Division of the New York Academy of Sciences Children's
     Science Book Awards.

        "From the creator of what I consider to be the best planisphere
     available (The Night Sky), comes Exploring the Night Sky with Binoculars,
     a companion to that star dial.  Taken together, the two items--plus a pair
     of binoculars--constitute the best introduction to observational astronomy
     you could ask for."
              --John Mood, Astronomy Magazine.        $ 5.95   _____   ______
              (Star Dial and Book ordered together)     $ 10   _____   ______

------------------------------------------------------------------------------
                                       7.75% Sales Tax (in CA only)    ______

   ** Overseas **      Large 3-D Viewer: (Air) $ 35, (Surface) $ 13    ______

   ** Overseas **  All other items, add: (Air) $  5, (Surface) $  2    ______

                                                              TOTAL:   ______
  (Checks must be payable in US Dollars drawn on a US bank)
  (Domestic shipping will be added to invoices if not paid in advance)

  (Preferred disk type)    5.25/360K,  5.25/1.2M,  3.5/720K,  3.5/1.44M
                         (We may substitute low density at our discretion)

   REGISTERED USER NAME_____________________________________________________
  (For registration: print user name exactly as you want it on the title page)

 Name________________________________________________________________________

 Address_____________________________________________________________________

 City__________________________________________________State______Zip________

>INSTALLATION

 DEEP SPACE 3-D, Version 3.0 comes on 2 floppy disks (the shareware disks)
 plus a third disk upon registration.  A hard is required to run the program.
 The distribution disks should contain:

 Disk #1 contains:

   INSTALL.BAT -- Type INSTALL for further installation instructions.

   DS3D1.EXE -- A self-extracting archive file.

 Disk #2 contains:   DS3D2.EXE, a second self-extracting archive file.

 Disk #3 contains:   Star Data Files SST02-SST06 (upon registration)

 If you got DEEP SPACE 3-D from a bulletin board, you may have received only
-DS3D1.EXE and DS3D2.EXE.  INSTALL.BAT is contained in the DS3D1.EXE archive.

 The hard disk installation program INSTALL.BAT creates a directory called
 \DS3D, (you can specify an alternate name for the base directory) and two
 sub-directories called \DS3D\DSDATA and \DS3D\DSFILES.  The files are grouped
 according to function for the program to be able to find them.

 \DS3D should contain:
    DS3D.EXE, DS3D.OVR, TEXT.TXT, CGA.BGI, EGAVGA.BGI, HERC.BGI, CONLINE.DAT,
    EXTSYMBL.DAT, LASERDOT.DAT, NAMENUM.DAT, NGCOBJCT.DAT, NGCSYMBL.DAT,
    and PLCRUNCH.DAT.

 \DS3D\DSDATA should contain:
    SACINDEX.DAT, SACINDX2.DAT, SACNOTES.DAT, SACREST.DAT,
    SST01, SST02, SST03, SST04, SST05, and SST06.
    (Future star data additions will also go here.)

 \DS3D\DSFILES should contain:
    CURRENT.CFL, RECENT.CFL, and CATEGORY.DAT.
    (Future comet *.CFL files will go here.  Output files generated by the
    program will also be placed here automatically.)

>PROGRAM REGISTRATION

 Registered users must imprint their REGISTERED USER NAME on the title frame of
 the program.  Registered users have access to all star files, expandable to
 SST77, the entire Saguaro Database of non-stellar objects, which includes the
 whole NGC catalog, and any number of comet *.CFL files.  All functions of the
 program work in both registered and unregistered form.

 To register, send payment to David Chandler Co., P.O. Box 309, La Verne, CA
 91750 and, print your REGISTERED USER NAME (either a personal or institutional
 name) exactly as you want it imprinted on the title page.  In return you will
 be sent the latest version of DEEP SPACE 3-D, a 3-D viewer, star files SST02-
 SST06, and a REGISTRATION NUMBER.

>SHARING DEEP SPACE 3-D

 Please share DEEP SPACE 3-D!  You are our best advertizement.  If you use a
 BBS, please upload a copy.  We want to get the word out that Version 3.0 is
 here.

 When you share the program with friends or colleague (we hope you do!), please
 share only the original archived files (DS3D1.EXE and DS3D2.EXE) and
 INSTALL.BAT.  If you use a BBS, please upload the only the two archives, or
 make an inclusive archive containing DS3D1.EXE, DS3D2.EXE, and INSTALL.BAT.

 We want to discourage sharing the loose files.  We want everyone to have not
 only the working program, but the ability to share it further.  They need the
 archived files to do this efficiently.

>CONFIGURATION

 When you start Deep Space 3-D for the first time, you are led through the
 configuration procedure.  You can alter your choices at any time by selecting
 the CHANGE CONFIGURATION option at the MAIN MENU.

 Video Mode:

 The first item on the configuration agenda is to specify the type of video
 card in your machine.  You may have a CGA card even with a monochrome monitor.
 The program will attempt to detect which card is present.  Under normal
 conditions you should be able to accept the default selection.

 Colors:

 Try the function keys as indicated to find a combination that is easily
 readable.  You can select colors for background, normal text, box background,
 and box text.  If you have a monochrome monitor, you can select dark on light
 or light on dark.  If things get out of hand, you can return to the default
-settings.

 Registration Status:

 If the program is unregistered, this option allows you to imprint your
 registration name and number.  If you want to use the program in unregistered
 mode, type <Esc>.  Type in the REGISTERED USER NAME and REGISTRATION NUMBER
 exactly as given on your registration slip.  The number is an encryption of
 the name, so they have to match for the registration to be considered valid.
 (If there is a misspelling of your name on the registration slip, use the name
 as shown, temporarily, and request a new number.)

 Keep your slip containing your REGISTERED USER NAME and REGISTRATION NUMBER
 for future reference.  If your configuration data is ever damaged or lost you
-may have to go through the imprinting process again.

 Directories:

 INSTALL.BAT stores your main program files in a base directory of your
 choosing.  (We will use \DS3D for the discussion here to make things more
 concrete.)  Data files that remain unaltered are put in \DS3D\DSDATA, and
 files created or altered by the program are put in \DS3D\DSFILES.  If you used
 INSTALL to set up your directories you can simply accept the default settings.

 You may arrange your directories differently, as long as you keep the file
 groups together.  (For instance, you can put everything into one big
 directory, if you prefer.)  Indicate the changes here so the program can find
 the files it needs.

 The program will check to make sure it can find all the critical files.  It
 will not continue if critical files are missing or misplaced.  When users have
 difficulties running the program after reorganizing their hard drives, this is
 the most common reason.  Running the DIRECTORIES configuration option will
-point to the files that are causing the problem.

 Observing Sites:

 You may save descriptions of a Primary and Alternate observing site.  A third
 site description may be defined "on the fly" while running various options in
 the main program.  It too will be stored until it is redefined.

 Find the latitude, longitude, and altitude (in feet) of your observing sites
 in a library or on a topographical map.  If you can't find exact numbers you
 need at least approximate numbers.

 A partial table of time zones is provided.  Daylight saving time shifts U.S.
 observers one hour closer to Greenwich (subtract one hour), and Asian
-observers one hour farther from Greenwich (add one hour).

 Miscellaneous items:

 You must specify the number of SST## (Star data) files installed.  You can
 access only SST01, if unregistered.

 When you include NGC objects on star maps you can select the magnitude limit
 at that time.  However the default magnitude limit can be adjusted here to be
 appropriate for the telescope or binoculars you most often use.  The NGC
 magnitude limit is independent of star magnitude limit.

 The standard coordinate system for comet elements has been equinox 1950.0.  In
 January 1992 the standard will change to a new system called J2000.0.  You can
 choose the system to use each time you enter comet elements, but you will
 probably want to change the default setting to "J" in January 1992.  Comet
 ephemerides are converted to equinox 2000.0 in either case.

 The program needs to know what kind of printer you have.  It supports standard
 9-pin and 24-pin dot matrix printers and laser printers comptaible with HP
 LaserJet II. If you get garbage on your printer, check this setting!

>HISTORY

 A Personal Note:

 People ask me how long this program took to write.  DEEP SPACE 3-D was not
 written all at once.  Nor was it originally written with the software market
 in mind.  Its roots trace back to the mid 1970's when I wrote star mapping
 routines on a time-share minicomputer and plotter to produce my planisphere,
 THE NIGHT SKY, and a now out-of-print set of cards entitled DEEP SPACE 3-D(!).

 The first micro-computer version was written for the TRS-80 Model I.  A star
 map took a half hour to compute and another 15 minutes (with a separate
 program) to dump to a printer.  It had no screen graphics.  I used it to
 generate comet finder charts for the Pomona Valley Amateur Astronomers, and
 worksheets for my astronomy classes and teacher workshops.  (I still do
 teacher workshops, by the way, if your school district might be interested.)
 The first release of the program as a software product had to wait until a
 fast enough PC came along, so star maps could be generated within the
-attention span of the general public.

 I feel it is wrong to characterize DEEP SPACE 3-D as a "Planetarium Program".
 It is not a "Video Star Show".  You can get fairly nice screen displays, but
 if you stop there you are missing the point.  The video aspect of the program
 was non-existent at first and has always been a secondary consideration.  Even
 now, you will notice, the scale and screen display are based on 8"x10"
 printout dimensions, there are no color graphics (I may add color evenually),
 and NGC objects are labeled simply with little rectangles to indicate where
 the printed names will appear.  Video graphics plays the same role in DEEP
 SPACE 3-D, as it does in desktop publishing: it allows interactive layout for
 customizing the printed output.  DEEP SPACE 3-D is "Desktop Cartography"!

 Some of you who have been on board since the early releases may wonder why
 certain features have been prioritized as they have, and why they have been so
 long in coming.  (The pace of development relates to the fact that I am a high
 school teacher, so most of my programming comes in summer spurts.)  As for
 priorities, comets were the first item because they have always been difficult
 to observe without heavy computational support.  They are no harder to see
 than galaxies of the same magnitude, but they are harder to locate because
 they move.  Planets were a lower priority because they are bright.  There are
-still more features to come in the planetary orbit department.

 The NGC's have been problematic.  I have had access to various NGC databases
 for several years, but they have always seemed so static--why bother, when
 there are such good atlases available?  Furthermore, it was not clear to me at
 first how best to handle all the clutter.  On-screen identification with a
 cursor is one thing, but printed galaxies with printed labels was a nightmare
 to contemplate.  Once I had the selection and labeling process clearly
 outlined in my mind my motivation increased, but time was still a problem.  It
 would not have been possible even this year without the cooperation of a very
 talented former student of mine, Jim Liebgott, who undertook implementing the
 NGC features.

 The lack of laser printer support has irked some of you for a long time.  I
 have always had a do-more-with-less attitude and have seen the 9-pin printer
 as the common denominator.  That is changing fast.  I bought my first laser
 printer last month for approximately what I paid for my first Epson MX-80 in
 the early 1980's!  I still intend to support dot-matrix printers, but the
-times, they are a' changing.

 Version 3.0 represents a qualitative breakthrough in the utility of DEEP SPACE
 3-D as an observer's tool.  Instead of just filling in the gaps where other
 resources were weakest, it now is a true general purpose observers resource
 package.  It brings together the functions of an almanac, an atlas (for
 everything from "Match-the-sky" constellation charts, horizon sky charts,
 through detail rivaling Uranimetria), a catalogue, a source of descriptive
 information, and an observing log.  All of that information is accessible at a
 glance.  The best part (believe it or not) is star maps you can write on!  I
 wouldn't have guessed it would make such a difference.  I have been using
 printouts from the pre-release versions of the program at star parties for the
 last several months, and it has transformed my observing experience.

 The SAGA's which started in the HELP file in Version 2.0, were my way of
 communicating some of the WHY that motivated the program design.  As is
 appropriate with the new developments, the saga continues...

>A SAGA IN THREE PARTS

                                    PART I
      A new comet is discovered!  It is faint now, but it is expected to
 brighten almost to naked-eye visibility (about 6th magnitude) in a few weeks.
 The newspapers won't carry stories about this one, but you know about it
 within a week of its discovery because you subscribe to COMET WATCH.
      You have had bad luck with comets in the past.  You tried to find
 Halley's Comet but couldn't find it in your brand new marketed-for-the-
 occasion telescope.  The bottom line is you couldn't find your way around the
 sky and didn't know exactly where to point the thing...but this time things
 will be different!  You have all the right tools: a sturdy star dial that you
 are using nightly to learn the constellations one by one, a nice little book
 that made you realize the value of those binoculars you had hidden up in a
 closet while you were struggling with your new telescope, and DEEP SPACE 3-D,
 the most versatile comet crunching computer program available.
      Back to our story.  COMET WATCH arrives in the mail.  You type in the six
 magic numbers that specify the comet's orbit.  Within minutes you have on the
 screen an ephemeris for the next two months.  "Ephemeris"...you just learned
 the word, but it has a nice ring to it.  It means lots of numbers!  You go on.
 Within minutes you have printed out a large-scale finder chart in "Star Atlas
 Mode" which you can use to spot the faint smudge with your binoculars, and in
-turn guide your telescope to its target...

      But that's not all.  You run What's Up for the current date and look at
 the rise and set times for the comet.  You see that the comet rises at 4am, so
 you run What's Up again, this time for an early morning hour.  You do another
 ephemeris, this one correlated with the current What's Up settings.  You plot
 an all sky map and see two paths for the comet: one showing its path relative
 to the constellations, just what you had before, and the other one showing its
 path relative to the horizons.  These paths gradually separate, since the star
 positions are for one particular night, but the comet is shown for several
 weeks, during which time the sky will have rotated considerably.  You use the
 cursor to identify the dates when the comet will be highest above the horizon
 and are pleased to see it will be well placed when it is at its brightest.
      You run yet another ephemeris, this one not for "finding", but for
 "understanding".  You plot out the whole orbit on the screen and see how the
 comet zips past the earth's orbit in its brief encounter with the sun before
 its slow return to the outer fringes of the solar system.  You put the cursor
 on the screen and use the "ID" option to step along the orbit, matching the
 earth's position with the comet's position day for day.  You plot out the
 orbit in 3-D to help visualize the orientation of the comet's orbit in space.
 It is apparent that this comet's orbit is highly inclined to the plane of the
 solar system.  The comet will loop up and over the earth, causing it to move
 far to the north in the sky then disappear below the southern horizon.  Not
-only are you confident of finding this comet, you have come to know it well.

                                     PART II
      You are a teacher planning a sky observation night for your students. You
 want to find a date when the moon is up for viewing in the evening sky but not
 so close to full that it will drown out everything else.  You want your
 students to get home at a reasonable hour, but you want to stay late enough so
 it will be fully dark.  You would like your students to see the rings of
 Saturn or the moons of Jupiter in a telescope, but you realize these planets
 are not always out in the evening sky.  How can you plan for a successful
 session in time to announce it to parents a month or more in advance?
      The What's Up option is the place you start.  You enter a rough target
 date and your observing site.  You immediately see the dates of all the new
 moons thoughout the year and all of the moon phases in your target month.  You
 pick a date near first quarter for a well placed evening moon.  (Craters show
+up best at first quarter because they cast long shadows then.)  The default
 observing time is the end of evening twilight, which looks OK to you, so you
 accept it.  You choose the ALTER DATE option to zero in on the day best suited
 for your event.  You print out the information screen for your own reference.
 With the date and time selected, you go on to check out the rise and set times
 of the moon and planets.  Returning to the main menu you run a full-sky star
 map for the event, limited to 3rd magnitude stars (since you know that's all
 that will be visible from town anyway).  You print it out, duplicate it, you
-are ready to go.

                                    PART III
      You are an avid amateur astronomer, out on a mountain top long past most
 people's bed time.  You run across a faint fuzzy object in your telescope that
 isn't on your star atlas.  You do a careful sketch of the field stars to get a
 fix on its position, estimate its magnitude, and watch it for a half hour or
 so to verify that it drifts slowly past the background stars.  It does!  You
 have a comet!  Anticipating immortality (for your last name at least) you risk
 life and limb rushing back down the winding mountain road...but before placing
 a telegram to Cambridge, MA, you decide to check What's Up first.

      You subscribe to COMET WATCH, so you have maintained a file of all the
 comets that have come by in the last few years.  You have copied the ones
 currently visible to a smaller file for easy access.  You run What's Up to get
 a listing of positions, estimated magnitudes, and rise and set times.  Just
 for good measure you run it for the whole file so nothing will slip by.  You
 don't like looking at long lists of numbers, so you select all the comets for
 inclusion on the star chart, return to the main menu and generate a star chart
 for the current day and time.  You choose the function key for "Planets etc."
 and every comet in the file shows up on the screen (most of them far too faint
 to be visible).  You immediately notice a comet close to where you found
 yours.  You put the cursor on it to identify it and go back to the What's Up
-option again to take a closer look...

      It becomes clear that the comet you discovered (you really discovered
 it!) was also discovered several months earlier by someone named Liller.  In
 fact you had looked at it back then when it was much brighter and had a nice
 tail, but it was in a totally different part of the sky.  It had dimmed down
 so much that you had removed it from your current comet file (CURRENT.CFL),
 but had the good sense to keep it in your backup comet file (RECENT.CFL).
 You're disappointed, but you realize that your thorough search has saved you
 from the embarrassment of a false alarm and the expense of a needless
 telegram.  Still you realize that your comet is out there waiting for
 you...but that's for another day.

 (That's how it might have been.  The truth of the matter is I didn't have
 What's Up at the time.  I did have Version 1.3 of DEEP SPACE up and running,
 and I did have Comet Liller on file!  If I had taken the time I could have run
 ephemerides for all the comets in the file and found that Comet Liller was
 still bright enough to be seen and right where it should have been...but that
 was too time consuming, so I just checked a few likely candidates.  I sent the
 telegram and later swallowed hard when I discovered my error.  I decided then
 and there to add a new option to the program.  That's why you and I have the
 handy What's Up option today.)

>THE SAGA CONTINUES...

                                     PART IV
      Having had a successful star party for your students and their parents,
 you want to really teach your kids to know the sky.  If they recognize star
 patterns they will notice for themselves that the pattersns stay fixed but the
 sky rotates each night and with the seasons.  If they know all the brightest
 stars, they will notice for themselves that there are some wanderers out there
 that outshine the brightest stars.  If they know the major constellations,
 they can take out their parents' binoculars and find the Andromeda Galaxy or
 and the Orion Nebula for themselves.  Space won't be such a distant
 abstraction if they can see galaxies and star clusters and nebulae for
 themselves.

      A one-shot star party may be a good experience, but it's not
 quite enough to really "own" the sky for oneself.  The problem is school is
 taught in the daytime, and evening events are difficult or impossible to
-arrange very often.

      As you prepared the star map for the big event, you were struck by how
 poorly school textbooks handle the constellations.  Not only do the poorly
 drawn textbook patterns not look like the mythological creatures they are
 supposed to represent, they look even less like the real sky.  What's more,
 they always seem to teach the patterns out of context.  That's why your kids
 see dippers all over the sky.  Context is the name of the game.  Your kids
 complain that the Constellations never look the way they are supposed to. Then
 it hits you: the way the stars actually are is the way they are supposed to
 look!

      You are not dependent on crude textbook drawings any more.  You can make
 worksheets with accurate representations of the real sky.  You decide to start
 by handing out star maps with no lines and no labels, no pre-conceived
 patterns.  The easiest stars to see and recognize are the brightest ones, so
 you start with those.  You have your kids circle the very brightest stars on
 their maps.  There are only a few that really stand out.  What patterns do
 they make?  You have the kids draw their own patterns using only the brightest
 stars and use the chart to find them in the sky.  When they can find a star
 reliably, you give them its official name.  Only when your kids "own" a few
-stars for themselves do you link them up with their fainter neighbors.

      Your junior observers begin to notice for themselves that some stars are
 redder than others.  You didn't have to present that as another "factoid" to
 be memorized and tested.  Some start paying attention to the brightest stars
 that are left off the chart, so you hand them another chart with planets
 included and begin exploring how they are different from the stars.  They are
 asking questions and taking the lead.  You are no longer in the position of
-dragging them through the material.

                                     PART V
      You are an enthusiastic amateur astronomer, having just moved up from a
 6" to a 16" telescope.  You have tried other astronomy programs for your
 computer before, but what you are interested in is the real sky, not the kind
 of poor imitation you get on a computer screen.  You already know the
 pleasures of spending dark nights out with the Milky Way arching overhead.  As
 you get to know your new program you realize it was designed with the observer
 in mind.  WHAT'S UP lays out all the basic sky information in a nutshell.
 Comets, planets, deep sky objects, ... it's all there.

      What you really want to see is deep sky objects: galaxies, clusters, and
 nebulae.  Like most observers, you have accumulated atlases and catalogs in
 ever increasing detail--and ever increasing bulk.  You have found that if you
 go out unprepared you tend to wander aimlessly, falling back on scanning over
-the old favorites.

      Crossreferencing turns out to be the name of the game.  You find a little
 star cluster on an atlas, turn to a catalog to check out its specs, turn to
 yet another reference for any tidbits of descriptive material.  You remember
 you found a few interesting clusters in the general area a couple years ago
 with your six inch, but which ones really grabbed you, you can't remember.

      This month you are going to try something different: clipboard astronomy!
 Three charts should do the trick, along with a printed observing list with the
 catalog data, descriptions and rise-set charts for each target object. You
 plan to focus on globular clusters in Sagittarius in the evening, open
 clusters in Cassiopeia a little later, and galaxies, along with whatever else
 can be found, far from the Milky Way in Cetus as it culminates after midnight.
 By the time the Orion Nebula rises you can kick back and bask in its blinding
 light, with the satisfaction that you have stretched yourself and done some
 real exploring.

      To prepare, you plot the maps and bring up the kinds of objects you want
 to include in your search, to a realistic magnitude limit for your equipment
 and experience.  As you cycle through the objects labeling them, you read the
-comments and weed them out one-by-one.

      You carry your clipboard of charts, catalog data, and commentary right up
 to the telescope with you.  You find you are spending the night at the
 eyepiece rather than running back and forth to your tailgate reference
 library.  Still, item for item, you have access to as much information as
 ever.  And you don't feel as protective of your clipboard materials as you
 would with your expensive two volume atlas, and three volume reference set.
 Apart from a little dew and dust, they survive the night in splendid
 condition.  You circle each object you find and make notes right on the maps!
 Gone is the reverential attitude toward the printed page.  These charts are
 throw-aways.  But really, they are keepers!  These are the kind of notes you
 will really use in coming months.  You date the charts, note the site and sky
 condition, and keep them to file away as part of your permanent observing
 record.

      But you don't file them away until you have brought the observing list
 back up on your computer.  You enter your notes to be seen instantly when they
 count the most next time.  For the first time you are building a truly
 meaningful observing log.  As you think back over the night you select a few
 objects to add to your list of all-time favorites.  You have had night to
 remember.

>DEFAULTS

 How do you make a program simple enough for a beginner and at the same time
 powerful enough to satisfy an expert?  One way is to allow lots of choices for
 the experts, even regarding picky details, but to suggest an answer to every
 question that at least makes sense.  A "default" is computer jargon for those
 pre-selected answers provided by the program.  DEEP SPACE 3-D has defaults for
 just about everything!  This makes it easy to explore areas you may not
 understand very well at first.  If you come to a question you don't care about
 or don't understand, just choose the default and keep going.  The more you
 learn about astronomy, the more you will appreciate having control over all
 the picky details.

 To choose a default answer, simply type the <Enter> key.  You will find you
 can go through almost the entire program simply hitting the <Enter> key, and
 still get something of interest.  If you come to a whole page of questions and
 like the looks of all the default answers, simply jump to the bottom of the
 page with the <PgDn> key and keep going.  As you get more comfortable with the
 program and read more about astronomy, you will find the program's
 capabilities will keep up with your growth along the way.

>DATA ENTRY

 There are several data entry formats.

 SCROLLING MENU:
 When you are presented with a menu having a highlighted scroll bar (eg. the
 MAIN MENU), make your selection with the arrow keys, the first letter of the
 desired option, or the <Arrow>, <PgUp>, <PgDn>, <Home>, or <End> keys.
 Finalize your selection with the <Enter> key or escape with the <Esc> key.

 INPUT BOX:
 Most single character entries do not require the use of the <Enter> key.
 Simply press the appropriate character key.  If you type an invalid character
 you will hear a beep and may try again.  Numbers and character strings require
 you to type <Enter> to terminate the entry.  If you choose to accept the
 default entry presented in the box, simply type <Enter>.

 TOGGLES:
 A third form of data entry is a "toggle".  To make or undo a selection, type
-the <Space> bar.

 DATA PAGES:
 For convenience, data entry is presented a page at a time.  You may use the
 <Arrow> keys, <PgUp>, <PgDn>, <Home>, or <End> keys to move among the data
 items.  You may not be allowed to leave a box until an entry of the proper
 format is present.  To allow you to recover from accidental keystrokes, there
 is usually a question at the bottom of a page for confirmation.  If you are
 satisfied with all the entries on a page you may jump directly to the bottom
 of the page with the <PgDn> key.

 EDITING AN ENTRY:
 When editing an existing entry, if the first key typed is a normal character,
 the entry will be erased under the assumption that you want to retype the
 whole entry.  If you want to edit the entry without destroying what is already
 there, make the first keystroke with a <Home>, <End>, or Arrow key.  After
 destroying a few entries you will get used to it.

>WHAT'S UP: SUMMARY PAGE

 The WHAT'S UP option generates a useful grab-bag of information for anyone who
 actively observes the sky.  After specifying a target date you are given
 information that you may want to use to refine your choice of date or narrow
 in on a time most suitable to your observing needs.

 The sun and moon both cast a lot of light and can hinder observations of other
 fainter objects.  New Moon equals No Moon.  The time of New Moon (plus or
 minus a few days) is the best time of the month for observing faint "deep-sky"
 objects.  First quarter moon will be overhead in the evening sky, setting
 around midnight.  The full moon is up all night and casts a tremendous amount
 of light.  The third quarter moon will rise near midnight, allowing good
 viewing during the evening hours.  First quarter moon is a good time for
 public viewing since the moon itself is a prime telescopic subject for the
 general public.  First quarter is also good because the craters cast long
 shadows along the terminator (the moon's "twilight zone") making them more
 visible.

 Sunrise and sunset are also important.  Times vary considerably throughout the
 year, especially at higher latitudes.  Astronomical twilight is defined as the
 time when the sun is 18 degrees below the horizon.

>WHAT'S UP: PLANETS, ETC

 The Planets section of WHAT'S UP gives a wealth of information for anyone who
 wants to read it.  You can print out the data if you like, or simply allow
 the program to digest the information and display it visually on star maps.

 COLUMN HEADINGS:
   R.A.       --Right Ascension: angle in hours, not degrees, measured
                eastward along the equator from the Vernal Equinox.
   Dec        --Declination: angle above or below the celestial equator
                measured in degrees.
   Long       --Ecliptic Longitude
   Lat        --Ecliptic Latitude
   Az         --Azimuth: angle in degrees measured eastward along the horizon
                from due south.
   Alt        --Altitude: angle in degrees above or below the horizon
   Elong      --Elongation: the angle of the planet from the sun measured along
                the ecliptic.
   Phase      --Angle between your line of sight and the direction of sunlight
                falling on an object.  Full phase is 0 degrees.
   Dist       --Distance from the earth in AU's, for planets, in earth radii
                for the moon.
-  Diam       --Angular diameter measured in minutes of arc.

 RISE-SET INFORMATION:
 Times of rise and set are shown graphically for ease of use.  The hours of
 darkness and twilight are indicated at the top of the page.  Times are
 centered on local midnight, regardless of what time zone you are using.  (eg.
 if you use daylight saving time you will notice that 1 am, not 12 am is at the
 center.)

 The dashed lines indicate the times the moon and planets are above the
 horizon.  The double lines indicate when they are more than 20 degrees above
 the horizon, a hypothetical "smog line".  Even if there is no smog, at 20
 degrees above the horizon you are looking through 3 times as much atmosphere
 as when you look directly overhead.

>WHAT'S UP: COMETS

 Comets are interesting observational targets, although beginners often have
 difficulty locating them because they move from one night to the next and
 accurate information has (up until now) been hard to obtain.  For success in
 comet observation you need an up-to-the-minute information source and the
 computational power Deep Space 3-D has to offer.

 If you want to follow a single comet over an extended period of time, use the
 COMET EPHEMERIS option.  If you want to know where each of the comets in your
 file is on a given night, use the WHAT'S UP comet section.  Usually not more
 than two or three comets are actually bright enough to see at one time, but
 the others are still out there and may be plotted.  This is especially useful
 if you think you have discovered a comet and want to avoid mistaking a known
 comet for a new discovery.

 The information given for each comet is R.A., Dec., Elongation, (see WHAT'S
 UP: PLANETS for explanations), predicted magnitude, and rise/set information
 in graphical form.  Magnitude estimates are notoriously unreliable, but they
 can give a good idea if a comet will be visible at all.  Whether magnitude
-information is given depends on the data available for the given comet.

 Finally, you are given the opportunity to "select" any number of comets.  If a
 comet is selected, it is put in a file with the planets to be displayed on
 star maps.  For selection purposes you have several options:

     Y: Select a given comet
     N: Reject a given comet
     S: Select all of the remaining comets
     R: Reject all of the remaining comets (but still scroll through them)
 <Esc>: Keep what has been selected so far, and quit.

 If you type S or R, you may interrupt the scrolling at any point with the
 <Esc> key and revise your selections from that point onward.


>COMET ELEMENTS

 Orbital elements are six numbers that describe a comet orbit's size, shape,
 orientation in space, and time of closest approach to the sun.  They may be
 entered in the COMET EPHEMERIS section.

 The elements have strange sounding names, but you don't have to know anything
 about them to be able to plug them into Deep Space 3-D.  If you subscribe to
 Comet Watch you will be among the first to know when a new comet is discovered
 or when a returning comet has been "recovered".  Comet Watch gives you the six
 numbers the program needs to know.  Simply plug them in and let the program go
 to work.

-The six magic numbers for comets are as follows:

                                Orbital Elements

 T     : Time of perihelion passage--when the comet is closest to the sun
 e     : Eccentricity--a measure of the elongation of the orbit.  For a
         circle, e=0.  For a parabola, e=1.  Above 1 the orbit is a hyperbola.
 q     : Perihelion distance--closest approach to the sun
 PERI  : Argument of perihelion--measures the orientation of a comet's orbit
         within its own orbital plane.  (Symbol = lower case Greek Omega.)
 NODE  : Longitude of the Ascending Node--locates where the comet's orbit
         crosses the ecliptic plane.  (Symbol = upper case Greek Omega.)
 i     : Inclination--the angle between the orbital planes of the earth and
         comet.

 These numbers are published in IAU Circulars by the Center for Astronomical
 Telegrams after a new comet has been discovered and tracked for several days.
 Refined elements are typically published after a longer period of observation.

 To enter data, choose the COMET EPHEMERIS option at the MAIN MENU.  When the
 existing comet files are shown, choose the CURRENT.CFL file.  When the comets
 in the file are displayed, type <Insert>.  You will be presented with the data
-entry form where new elements can be typed in.

 If you want to understand the orbital elements, think of a book resting on a
 table.  The surface of the table represents the plane of the earth's orbit.
 The cover of the book represents the plane of the comet's orbit.  You cut out
 a paper ellipse and tape it on the cover of the book.  The shape of the
 ellipse is determined by the eccentricity (e) and its size is determined by
 any linear dimension, in this case the distance from the focus to one end of
 the ellipse (q).  The angle of perihelion (PERI) is the angle of rotation of
 the ellipse relative to the binding of the book.  The inclination (i) is the
 angle the cover is lifted as the book is opened.  The longitude of the
 ascending node (NODE) is the angle of the book binding relative to the edge of
 the table as the book is rotated on the surface of the table.  These five
 elements determine the geometry of the orbit.  The time of perihelion Passage
 (T) pins down the location for one specific time, and Kepler's laws of
 planetary motion (which ultimately reduce to Newton's law of gravitation)
 determine the rate of motion and allow prediction of where the comet will be
 in its orbit at any other time.

 The bottom line is, you must type the right numbers into the right boxes to
 let the computer do its thing correctly.

>COMET FILES

 If your interest in comets is purely observational, you can delete most long
 period comets after they have faded.  They will never return in your lifetime.
 However, for other aspects of comet study you may want to collect orbital data
 to compare comets even after they are long gone.  For instance, some recent
 comets are suspected to be returns of ancient comets.  Comparing orbital
 elements (or 3-D views of the orbits) can give an indication if this is the
 case.

 An optional data disk has data on over 1100 comets (Based on Brian Marsden's
 Catalog of Cometary Orbits) dating back to the first confirmed sighting of
 Comet Halley in 240 BC (which astronomers refer to as the year -239.  For
 astronomers, the year preceding 1 AD is 0 AD.  For historians the year
 preceding 1 AD is 1 BC.)

 If you collect large amounts of orbital data, you can best organize the data
 by keeping it in multiple files.  The CURRENT.CFL and RECENT.CFL files are on
 the disk initially.  Other *.CFL files may be added without limit.

 To start a new file with fresh data, choose the COMET EPHEMERIS option at the
 MAIN MENU.  When the existing comet files are shown, type <Insert> to start a
 new file, and type in the new file name when asked.  You will then be
-presented with the data entry form where new elements can be typed in.

 Comet data can be copied to a new file or between existing files.  To do this,
 select a comet in an existing file, and choose the Copy option shown at the
 bottom of the page when its elements are displayed.  A menu of existing comet
 files will be shown allowing you to select which file to copy it to.  If you
 want to start a new file, type <Insert> to enter the new file name.

 Another option at the same point where the copy option is offered, is to
 delete a comet.  You may well want to enter new comet data in CURRENT.CFL,
 then copy it to RECENT.CFL and delete it from CURRENT.CFL when it is no longer
 easily visible.

 The program CONVERT.EXE is a separate program supplied with DEEP SPACE 3-D
 which must be in the same subdirectory as the comet files.  It will convert
 *.CFL files to or from the old Ver. 1.3 *.DAT files, and also to or from ASCII
 *.TXT files that can be read, edited, or organized with a text editor or word
 processor.  If text files are to be converted back to *.CFL form, they must be
 in pure ASCII and follow the exact pattern of the text files produced by
 CONVERT.EXE.

>DAY AND TIME OPTIONS

 You can enter the starting day and time and range of dates for a comet
 ephemeris in several ways, depending on the purposes you have in mind.  If you
 want the program to display a comet orbit in relation to the earth's orbit,
 choose the "A" option.  This allows you to select the calculation interval and
 number of calculations, and the program chooses the starting date to be
 symmetric about perihelion.

 If the comet has a relatively short period you will be asked if you want to
 compute positions for an entire orbit.  If you intend to display the comet on
 the screen, there is room in the allocated memory space for 500 points,
 counting the comet head, comet tail, sun, earth, and any other planet or comet
 positions that might be included.  Based on this space, the program will
 propose an interval and a number of positions to close the orbit.  Look at the
 proposal and decide if it will be satisfactory for your purposes.  Remember,
 comets move very quickly near the sun and very slowly far from the sun, so the
 jumps can get to be quite large if the interval is too long.  If the interval
 is 10 to 30 days, the results will usually look reasonably good.  If the
 interval needed to get a complete orbit exceeds a year, the option is not even
-offered.

 If star maps are computed for a given day and time, comet ephemeris
 calculations must be coordinated with this data to be meaningful.  This is
 done automatically when you choose option "B".  Option B ephemerides are
 linked to particular WHAT'S UP computations.  All you have to do is specify
 the computation interval and number of computations.

 The C option produces special search charts for comet recovery.  When comets
 return after long times at the far end of their orbits their orbits are
 frequently altered.  The most affected orbital element is the time of
 perihelion passage, T.  To aid in finding "lost" comets the Comet Recovery
 Mode predicts a range of positions for each date.  The printed ephemeris looks
 like the ephemerides produced by the other options, but the maps that use this
 data are very different.  For each day of the ephemeris there is a single
 position for the "on time" comet, marked with a + and possibly a tail, and a
 range of positions for early and late arrival, marked with x's.  How far the
 search path is extended depends on the uncertainty in perihelion time provided
 by the user.  The time interval between the x's is the same as the time
 interval between the +'s.  Unless you are an active comet hunter you will
-probably never have a need for this option.

 The D option allows direct entry of day, time, and calculation interval.  The
 program displays the times of sunrise, sunset, morning and evening twilight,
 and the rise/set chart for the comet.  All the information you need is there
 when you need it.

 Since the four time selection modes are for different purposes, their
 ephemeris files are marked with different extensions: *.EPA, *.EPB, *.EPC &
 *.EPD. When you want to do orbit plots, *.EPA files will be listed.  For Day
 and Time charts, only *.EPB files will be listed (and you will be warned if
 the one you choose has incompatible dates).  For comet recovery charts only
 .EPC files will be listed.  For other charts, all types of files will be
 listed.

>COMET EPHEMERIDES

 An ephemeris (e-phem'-er-is, plural: e-phe-mer'-i-des) is a numerical listing
 that shows where a celestial body will be in the sky over a range of dates.
 The ephemeris listings produced by Deep Space 3-D also give information about
 the appearance and spatial location of comets.  The headings are as follows:

  (The range of dates goes down the left side of the page.)
   R.A. & Dec --Position in the sky in equatorial coordinates
   R          --Distance from sun to comet
   Delta      --Distance from earth to comet
   Elong.     --Elongation: angle from sun to comet as seen from earth
   Phase      --For a comet this tells to what extent the tail points away
                from us.  90 degrees is directly across our line of sight.
   PA         --Position angle: the angle of the tail in the sky measured
                counterclockwise from north
   Mag.       --Estimated magnitude (emphasis on estimate!) if you have entered
                magnitude data for the comet.

 If you are planning to plot the comet path on a star map be sure to save the
 output as a file.  If you wish to export the printed ephemeris to a word
 processor, save the printout as an ASCII file as well.

>STAR MAP TYPES

 STAR ATLAS MODE
 General purpose star atlases use Equatorial Coordinates.  North is up, (unless
 you specify South up) and the time and horizon are irrelevant.  If you want to
 map a particular constellation or particular part of the sky, this is the
 option you will probably want to use.

 DAY AND TIME MODE
 Since the earth rotates, the sky changes constantly.  A chart printed in DAY
 AND TIME MODE takes the horizons into account.  It can show the whole sky or,
 by using the zoom feature, a horizon view facing in any of 16 compass
 directions.  If you want to observe throughout the night you will want a
 planisphere (a "Star Wheel" such as THE NIGHT SKY, available from David
 Chandler Co.) that can be taken into the field and updated from one hour to
 the next.  For a specific celestial event, or brief observing period, however,
 Day and Time mode charts generated by Deep Space 3-D will do very nicely.
 They are ideal for passing out to a scout troop or school group for an
-evening's sky orientation.

 SOLAR SYSTEM MODE
 The plane of the solar system is called the ecliptic plane.  SOLAR SYSTEM MODE
 uses Ecliptic Coordinates which tell how far around and how far above or below
 the ecliptic plane an object lies.  These charts are most useful when studying
 motions of objects in our solar system.  The circle where the ecliptic plane
 meets the sky is called simply the "ecliptic".  It passes through the Zodiac
 constellations, the path of the sun, moon, and planets through the sky.

 MILKY WAY MODE
 The Milky Way forms a circle around the sky because it is a disk, and we lie
 within the disk.  We are not at the center of the disk; we are off at one
 edge.  When we look toward the center of the galaxy the Milky Way looks
 denser.  The center is in the direction of the constellation Sagittarius.
 In MILKY WAY MODE the plane of the galaxy is horizontal.  Zero degrees
 galactic longitude and latitude is looking directly into the center of our
 galaxy.  MILKY WAY MODE is useful for studying distributions of objects
 relative to the plane of our galaxy.  Open clusters, for instance, tend to lie
 along the Milky Way.  Galaxies avoid it, since dust in the plane of our galaxy
 blocks the view of the outside universe.  The distribution of globular
 clusters centers on one point in the Milky Way: a point in Sagittarius.  This
-is how it was first determined that we are off-center.

 MATCH THE SKY MODE
 Ben Mayer, a well known amateur astronomer in California, has popularized a
 handy star-finding device made by bending a coat hanger into a rectangle and
 covering it with transparent plastic wrap.  Stars are marked on the plastic
 with white correction fluid (to be visible with a flashlight at night) in such
 a way that they exactly match the sky when held a short distance in front of
 the eyes.  These star finders are especially handy for showing constellations
 to beginners.  The weak point in the system, until now, has been finding how
 to place the dots to match the sky.  MATCH THE SKY MODE solves the problem.
 Make a print-out of the constellation of interest and trace it onto the
 plastic wrap.  This can be a great classroom project for teachers at any grade
 level.

>MAP PROJECTIONS

 When a spherical surface is plotted on a flat map stretching will always
 occur.  The question is what kind of distortion is least bothersome for a
 particular application.  Some projections distort shapes, others distort
 areas.  Others introduce more exotic distortions.  Generally speaking, for
 constellation recognition preserving shapes is important.  Thus the collection
 of projections offered in Deep Space 3-D specializes in shape preserving
 projections of one kind or another.

 The STEREOGRAPHIC PROJECTION should not be confused with stereo viewing of 3-D
 images.  (The possible confusion is particularly apparent in this program that
 highlights stereo 3-D!)  Basically, to flatten out a rubber ball, the edges
 must be stretched, causing a lengthening in the east-west direction.  The
 Polar Equidistant Projection has just such a distortion.  The Stereographic
 Projection compensates for the shape distortion by stretching the surface
 radially so east-west and north-south distortions match at every point.  The
 result is gross exaggeration of size far from the center, which is the price
 paid for keeping the shapes correct.  Overall, the Stereographic projection is
 a reasonable compromise for general purpose use, so it has been chosen as the
-default projection.

 The POLAR EQUIDISTANT PROJECTION is the one typically used for planispheres.
 It distorts shapes more but sizes less than the stereographic projection.  It
 is a reasonable compromise if less than half the sky is to be plotted.

 The MERCATOR PROJECTION was designed for navigation.  If you follow a compass
 bearing with a Mercator Projection you will get to your destination.

 For celestial use it is more relevant to note that this map has the same kind
 of "compensatory stretching" as the Stereographic map, so it also preserves
 shapes at the expense of gross area distortion far from the center line.  But
 whereas the Stereographic projection is accurate at a point, the Mercator
 projection is accurate along a line.  The Mercator Projection is a good choice
 for wrap-around views of the sky.  Two variations are offered here: N-S and
 E-W, depending on the nature of the material to be mapped.

 The GNOMONIC PROJECTION is the kind of a projection produced by a camera.  You
 might think this would be the ideal projection, but both size and shape are
 grossly distorted far from the center.  It is, however, a useful projection
 for small areas, especially if computer generated star maps are to be overlaid
 onto photographs.  The Gnomonic projection is used in MATCH THE SKY MODE.

>"HOW TO..."

 ...PLOT A WRAP-AROUND MAP OF THE WHOLE SKY
 For a wrap-around view of the sky with the celestial equator running
 horizontally through the center of the picture, choose STAR ATLAS MODE.
 Choose the direction of view by COORDINATES, not by constellation.  Center on
 0h RA and 0 degrees DEC.  Choose the scale to be 360 degrees per 10 inches.
 (The map length will print out 8" by 10".)  Choose projection "E" for East-
 West Mercator and orientation "H" for horizontal format.  Limit the stars to
 3rd or 4th magnitude, since you will be cover the whole sky.

 If you want the ecliptic (Zodiac) to run horizontally, use SOLAR SYSTEM MODE
 and follow the same steps.

 If you want the Milky Way to run horizontally, choose MILKY WAY MODE and
 follow the same steps.

 If you want to highlight the Milky Way, plot lots of stars (there is a 5000
 star limit on any given map).  Another way is to plot Open Clusters.  Once the
 map is displayed on the screen and the menu box is displayed, hold down the
 <Shift> key to bring up the secondary menu and type <F1>.  Select Open
 Clusters down to about 10th magnitude.  The number of clusters that can be
-plotted is limited by the available memory to the 640K limit.

 ...DISPLAY A COMET ORBIT AS SEEN FROM SPACE
 From the MAIN MENU choose the COMET EPHEMERIS option.  Select the comet file
 and the comet you want to study.  For the Date and Time option choose method
 "A".  This will produce a set of positions symmetric about perihelion, the
 point of close approach to the sun.  Run the ephemeris and save the results to
 a file.

 Now return to the MAIN MENU and select COMPUTE NEW STAR MAP.  If you want the
 earth's orbit to appear horizontal, use SOLAR SYSTEM MODE.  Choose view
 direction by coordinates.  To look down on the earth's orbit at an angle, use
 a slightly negative latitude (-25 degrees) for a start (any longitude).  Vary
 the view direction any way you want once you know what you are looking for.

 When the map is plotted on the screen, type <F6> and choose option "S" to view
 the orbit from space.  Select the file you created in the COMET EPHEMERIS
 option.  Tails will be small in this kind of printout, but they can be
 included if desired.

 The Sun will be shown at the center and the oval path is the earth's orbit,
 shown for comparison.  The comet path may be elliptical or parabolic and may
 be inclined at any angle.  You may want to generate views from several
-directions to find a pleasing perspective.

 Now comes the good part.  Choose the <F7> cursor option.  The cursor should
 land on the sun and a box at the top left corner of the screen will say SUN.
 Typing the <Enter> key, the cursor will jump sequentially to each position
 that was plotted, identifying the object and the date.  To speed up the
 process type the <End> key to disable the identification box.  (There is no
 mention of the <End> run option in the program itself; you have to learn it
 here.)  Typing <End> again will bring the box back.  Since the comet and earth
 positions were plotted alternately (for the innermost 1 year), holding down
 the <Enter> key will provide an animated view of the earth-comet encounter.
 The motion can be stopped at any time to read the dates.

 Several comets can be put on the screen simultaneously as long as the total
 number of points (counting heads, tails, sun and earth) does not exceed
 500.  If tails are left off, more comets can be included.

 Once the orbit plot is plotted, it is best viewed in 3-D.  To make a SMALL
 SCALE 3-D plot, type <F9>.  Use <PgUp> and <PgDn> to enlarge or contract the
 view box, and the arrow keys to move it around.  Type <Enter> to finalize your
 selection and print it out.  To plot the large scale 3-D for use with the
-optional table-top viewer, type <F10> and select the 3-D option.

 ...MAKE COMET FINDER CHARTS
 Run WHAT'S UP to set the date and find what time of night the comet will be
 visible.  Run WHAT'S UP a second time, if necessary, to specify an appropriate
 time of observation.  If you only want the position of the comet for a single
 night, go ahead and "Select" the comet at this point.  If you want the
 position of the comet over a range of dates, however, go to COMET EPHEMERIS
 and use option "B" for a range of dates starting with the one specified in
 WHAT'S UP.  Get a printout as you run the ephemeris so you can locate the
 center of view easily.

 Now go to COMPUTE NEW STAR MAP.  Choose STAR ATLAS MODE and select view
 direction by COORDINATES, not constellation.  Use the mid-range values of RA
 and DEC from the ephemeris printout as the center of view.  Once the map is
 plotted on the screen type <F6> to add the comet path.  Choose the "E" option
 for view from earth, and select the tail option, whether you think there will
 be a tail or not.  It is a good reference for observations.

>STELLAR MAGNITUDE

 Star brightness is measured on a "magnitude" scale.  This is a scale
 originally based on naked eye estimates of brightness.  First magnitude
 represents the brightest category or "First Rank" stars.  Sixth magnitude
 represented the faintest stars visible to the unaided eye.  Thus increasing
 magnitude implies decreasing brightness.  Telescopes have extended the scale
 to much higher numbers and photometers have increased the precision to several
 decimal digits.

 Generally speaking, if you want to plot naked eye stars, you should cut off
 somewhere around 6 or 6.5, depending on whose eyes we are talking about: about
 6000 stars.  If you want a whole sky map, this is far too many stars for a
 useful chart.  The single file database with the UNREGISTERED version goes
 down to Mag. 5.6, with over 3200 stars.  The 6-file database that comes with
 REGISTERED version goes a little beyond Mag. 7.25, for a total of more than
 19,000 stars. The whole 77 file database go down to about Mag. 10, with spotty
 coverage near the limits, nearly 250,000 stars in all.

 The full database is most useful when you want to look at a small part of the
 sky in detail.  With the full database you could plot the Pleiades star
 cluster to a scale of 1 degree per inch, and still have a field rich in stars.

>USING THE CURSOR

 Once a map is plotted, a number of interactive features are provided:

 <F1> brings up a cursor.  Move it with the arrow keys, for small jumps, or
 with the arrow keys in conjunction with the <Shift> key for single pixel fine
 adjustments.  (The <Shift> key will only work with the arrow keys that are
 part of the numeric keypad.)  If the cursor is centered on any object (star,
 planet, comet, etc.) the object will be identified.  If two stars are overlaid
 on the same pixel, both stars will be identified in sequence.  (If you have an
 "enhanced" keyboard, the two sets of cursor keys may not work the same.  Try
 both sets.

 <F7> uses the cursor in a different way.  If planets or comets are "overlaid"
 onto the star map, the <F7> cursor will jump from one to the next.  For comets
 and planets generated by the WHAT'S UP routine it will simply give the name
 of the object.  For comets generated by the ephemeris routine, it will give
 the name of the comet, and also the date, since the different images are for
 different dates.  One particularly impressive use of the <F7> cursor is to
 trace out the path of a comet orbiting the sun along with the earth.  See the
 COMET PATHS FROM SPACE section for more details.


>SAVING AND MODIFYING MAPS

 The <F2> function key cycles through a number of useful options for saving,
 re-displaying, and altering maps after their original computation.

 Star maps may be saved, previously saved maps may be restored, and the number
 of stars on the map may be increased or decreased.  A saved map can be
 restored much faster than it can be computed in the first place because all
 the heavy math has already been done.  This feature will be especially
 appreciated by those who have the older slower PC and XT type computers
 without math co-processors.

 A saved map may be redisplayed either from the <F2> function key or from the
 main menu.  A directory of all saved maps will be generated from which you can
 select a map with the scroll bar.  Once a map is restored it is ready for any
 function that could be performed on a freshly computed map.

 Specific constellations may be highlighted or faint distracting constellations
 can be suppressed with another <F2> option.  Label the constellations ahead of
 time and delete the names of the constellations you wish to ignore.  Using
 <F2> you can re-draw the constellation lines for named constellations only.

>ZOOMING

 To Zoom a star map that was printed in Star Atlas, Solar System, or Milky Way
 modes, type the <F3> function key.  A rectangular box will appear at the
 same proportions as the full-screen map.  Manipulate the box with the <PgUp>
 <PgDn> and Arrow keys to frame the view that is desired.  For finer
 adjustments use the same keys in conjunction with the <Shift> key.  <Enter>
 actuates the zoom.  Once the map has been zoomed, typing <F3> again will
 restore the original dimensions.  If the print option is chosen while a map is
 zoomed, the zoomed view will be printed.

 The Zoom feature is different for Day and Time Mode.  Here the Zoom takes you
 from a whole sky view to a horizon view.  Directions are specified by the
 points of the compass: N, S, E, and W specify the quadrants; NW, NE, SW, and
 SE split half way between the primary divisions; N-NE, E-NE, E-SE, S-SE, etc.
 split the difference once again for a total of 16 possible directions.  The
 Left and Right Arrow keys step by 16ths, the Up and Down Arrow keys step to
 the nearest 8th, the <PgUp> and <PgDn> keys step to the nearest quadrants, and
 the <Home> and <End> keys jump to North and South.  <Esc> takes you back to
 the whole sky view.

>CONSTELLATIONS

 Constellation lines are drawn with the <F4> key.  Once they are drawn, the
 <F4> key generates constellation names.  Once the names are generated the <F4>
 key is used for moving the names.

 The constellation names present a bit of a programming challenge if the goal
 is to use them on printouts.  First, they tend to obscure the stars, and
 secondly, the screen representations (which differ from one type of video
 monitor to another) may bear little resemblance to the actual text size on
 paper.  Furthermore, not all constellation names that show up on the screen
 may be desirable.  Sometimes only a tiny corner of a constellation intrudes on
 the edge of the paper and you may want to ignore it. Or, if you are dealing
 with students, you may want to focus their attention on a few of the brighter
 constellations only.

 To solve these problems as conveniently as possible the following method has
-been devised:

 1. Constellation names on screen are in the smallest font available.
 2. Names are popped into position automatically on the second <F4> for quick
    and easy identification of constellations even though they might overwrite
    significant details of the maps.  Each constellation name is associated
    with the brightest star of a constellation that is shown on the screen,
    usually displayed a short distance to the right of the star.
 3. By typing <F4> a third time you can enter a mode that will cycle through
    the constellation names, forward through the alphabet with the <Enter> key,
    or backward with the <Backspace> key.  The highlighted name can be
    positioned with the arrow keys, in conjunction with the <Shift> key for
    finer spacing.
 4. As a name is being moved, it is represented by a small rectangle that
    represents the computed size of the printed version of the name.  This
    will aid you in placing it properly.  Once the <Enter> key is typed the
    abbreviation of the name will pop to the location of the rectangle.
 5. For crowded conditions you may wish to substitute the three letter
    abbreviations for the full constellation names.  Use the <PgDn> key to
-   shift to abbreviation mode and the <PgUp> key for full name mode.

 6. Double word names, such as "Ursa Major" or "Canis Minor" are by default
    placed one above the other.  The <End> key will link them end-to-end and
    the <Home> key will return them to stacked form.  The form of each double
    name is controlled individually.
 7. Names may be deleted with the <Del> key.
 8. If you plan to print out a zoomed view, you should postpone positioning the
    names until your final step before printing.  Names positioned for one view
    do not necessarily match what would be desirable in a zoomed view, so the
    names and offsets are canceled upon zooming.
 9. If constellation lines are drawn the <F2> Save/Modify command offers an
    option to erase all the lines and draw only the constellations that are
    named.  Faint constellations that might be a distraction for some purposes
    can be eliminated in this way.

>PLANETS, ETC.

 Planets come in two varieties: those that outshine most if not all of the
 stars (Mercury, Venus, Mars, Jupiter, and Saturn), and those that require
 optical aid even to be seen (Uranus [borderline], Neptune, and Pluto).  The
 positions of the Sun, Moon, and all the planets are computed in the WHAT'S UP
 routine.  This information may be displayed on a star map (any variety) by
 pressing the <F5> key.  On first press the sun, moon, and bright planets will
 be shown.  To get Uranus, Neptune, and Pluto, press it a second time.  Any
 comets computed with the WHAT'S UP routine will also be shown along with the
 bright planets.

 The planets are identifiable by their symbols.  Further identification is
 possible using the <F7> key to jump from one to the next, displaying their
 names in a box at the top left corner of the screen.  Planets may also be
 identified manually by placing the <F1> cursor on the symbol.  For symbols
 with a circular portion, such as the Sun, Moon, Earth, Mercury, Venus, Mars,
 and Uranus, the location of the planet is the center of the circle.  The
 asymmetric symbols for Jupiter, Saturn, Neptune, and Pluto, have a small dot
 added near the center of the symbol for positioning.

>COMET PATHS FROM EARTH

 Comet paths seen from earth could be termed "finder charts".  They can be
 plotted on any kind of base map, but equatorial "Star Atlas" mode and "Day and
 Time" mode charts would usually be the most useful.  (See HOW TO... for step-
 by-step instructions in producing a finder chart.)

 A word here about comet tails is in order.  The tail displayed by the program
 is in no way a prediction of actual tail length: it is fixed at an artificial
 a 1/10 AU length (about 10 million miles).  However, it does reflect the
 effect of distance and phase on apparent tail length, and it is shown at the
 correct position angle on the sky for an ion tail, which points directly away
 from the sun.  This can be a useful observing aid if you think you detect a
 possible faint tail and wonder if it is in a plausible direction.  Remember,
 some comets have anti-tails and dust tails are sometimes quite curved.  The
 length of the displayed tail is the length the tail would appear if it were
 actually 1/10 AU long.  If the observed tail is half that long you know that
 the physical length is about 5 million miles.  The plotted tail is thus not a
-prediction, but a reference for observations.

 Another interesting question arises when plotting a comet path on a Day and
 Time mode star map.  By definition a Day and Time mode map is for a particular
 day and time, yet also by definition, a comet path is extended over a period
 of time.  How can the two be meaningfully combined?  The method of display
 here is somewhat of an innovation, but I think it is a very helpful way to
 treat the data.

 On the Day and Time mode maps, two paths are shown: one follows the path of
 the comet relative to the stars, the other follows the path of the comet
 relative to the horizons.  If the starting day for the ephemeris matches the
 date of the map, the two initial marks will coincide.  But then, since the sky
 rotates over the plotted interval, the two paths diverge.  The normal plot
 (+ marks with a tail if selected) indicates the path relative to the stars.
 The other path is marked with X's.  This is the path that for a given time of
 night shows when the comet will be highest above the horizon and how long it
 will remain in the observable portion of the sky.  Some comets are "horizon
 huggers", so this information is critical to evaluating their potential
 visibility.

>COMET ORBITS FROM SPACE

 When a comet ephemeris is generated with the "A" option (symmetric about
 perihelion) it is suitable for tracing out the whole orbit, or a significant
 portion of its inner orbit, as seen from a point off the earth.  For step-by-
 step instructions for creating an orbit view of this type see the HOW TO...
 option.

 Finder charts are for observers.  Orbit charts are for understanding.  They
 show what is happening in a 3-dimensional sense.  If you step through the
 orbit with the <F7> key you can come to understand why the earth-based view is
 as it is.  Sometimes the comet comes close to the earth's orbit, but not while
 the earth is at that part of the orbit.  One instructive game to play is to
 vary the Time of Perihelion Passage in the comet elements list.  Find the date
 when the comet is nearest the earth's orbit.  Continue stepping with the <F7>
 key and find when the earth is at that same position.  If the comet reaches
 that point 100 days ahead of the earth, adjust the time of perihelion passage
 to make it 100 days later in arrival time.  Halley's comet in 1910 had a near
 miss: we went through its tail.  In 1986 the comet was not very spectacular.
 We were at a different point in our orbit when the comet came by.  It all has
 to do with the earth being at the right place at the right time.

>CLEARING OVERLAYS

 The Planet and comet images on the video screen can be thought of as overlays
 superimposed on a base map of stars.  Typing <F8> (followed by a confirming
 "Y") clears the overlays without having to start the map computation from
 scratch.  You can thus experiment with various options without committing to
 them for the final printing.

>3-D / LARGE AND SMALL

 Space is 3-dimensional.  The sky we see is a two dimensional surface because
 of the limitations of our depth perception.  At great distances all things
 look the same distance away, hence we seem to be at the center of a sphere.
 In other words, the dome of the sky is an illusion.  It takes the illusion of
 stereo graphics to dispel the illusion of the sky.

 To see 3-D you need two points of view that are sufficiently far apart
 compared to the distances of the objects being viewed.  In a room, normal eye
 spacing gives ample depth perception.  Depth is easily judged 10 or 20 feet
 away by eyes that are about 2.5 inches apart: a factor of 50-100 eye spacings.
 Keep this in mind when it comes to plotting stereo views of the stars.  A
 simulated "eye spacing" of a few tenths of a light year will bring out depth
 well into the distance among the stars.  Over doing the eye separation is like
 trying to look at something an inch or two in front of your face.  On the
 other hand, increased eye spacing can bring out the relative depth at greater
 distances if there are few nearby stars sitting distractingly on the end of
 your nose.  Be flexible and experiment.  See for yourself the difference
-changing the eye spacing makes for different views.

 To see 3-D you probably need a viewer.  Some people can teach themselves to
 view the small scale 3-D views without a viewer, one eye looking at each
 frame.  (Some people do this by crossing their eyes, so a reversed field
 option may be selected at the time of the printout to accomodate this method.)
 Using a viewer makes the process much easier.  The small scale 3-D views are
 printed at the usual spacing of human eyes.  The viewer that comes with the
 registered version of the program helps focus each eye onto a separate
 picture.  The brain fuses the information from the two slightly different flat
 pictures into a single 3-dimensional image.

 The large scale 3-D printouts are for use with the optional table-top viewer
 which uses mirrors.  With the large viewer two 8-1/2 x 11 sheets can be viewed
 side-by-side for an incredible sensation of depth.  It's like sticking your
-head into a porthole!

 Some of the things to notice when viewing the stars in 3-D:
 --Some stars are bright because they are close, whereas others are bright
   because they are BRIGHT.
 --Some pairs of stars are close together in the sky but far apart in space.
   Other stars are far apart in the sky but close to each other (and us) in
   space.
 --Some familiar constellations contain actual star groupings, others only
   apparent groupings.

 Besides viewing the stars in 3-D, try viewing the planets and comets in 3-D.
 When solar system objects are present the stars are flat in the background
 since they are so much farther away by comparison.  Eye spacings are now
 specified in Astronomical Units (AUs) rather than light years.  1 AU is the
 distance from the earth to the sun.  An AU is to a light year as an inch is to
 a mile (almost exactly!).  Planets are really very local.  Using the distance
 to eye spacing ratio of 50 or 100 as discussed above, a 3-D view looking at
 the sun and inner planets from the earth should require an eye separation of
 only about 0.01 to 0.02 AUs.  0.1 AU is adequate for viewing a comet orbit
-from the distance of Jupiter.

 When comets are seen in 3-D the main point of interest is the orientation of
 the orbits relative to the earth's orbital plane.  Most of the solar system is
 flat, but comets come in from all angles.  The inclinations stand out
 dramatically in this format.

 The mechanics of getting the 3-D views is simple.  For small scale 3-D hit
 <F9>. A square frame will appear on the screen.  Zoom it in and out with the
 <PgUp> and <PgDn> keys and move it around with the Arrow keys.  Make fine
 adjustments with the same keys in conjunction with the <Shift> key.  Hit
 <Enter> when the desired view has been selected.  Whatever has been chosen
 will be scaled to a 2.5 inch format and printed in stereo.

 The large scale 3-D views are whole page printouts and are requested through
 the <F10> printout option.  Simply type <F10> as printing normally, but answer
 yes to whether you want the printouts to be in 3-D.

>PRINTOUTS

 To make printouts of a whole map or a zoomed view, display whatever features
 are desired on the video screen and then print by typing the <F10> key.  You
 will be asked whether you want the view to be flat or in 3-D.  This would be
 for the large scale 3-D view printed out on two consecutive pages.  If you
 have chosen a horizontal format and have the large viewer, the two 8-1/2 x 11
 inch pages of fanfolded paper can usually be left attached for viewing in
 stereo.  Keep in mind that each picture in a stereo pair has points that are
 offset from their normal positions, so the 3-D option is inappropriate if you
 intend to use the printouts as finder charts at night.

 Version 3.0 now supports laser printers compatible with the HP LaserJet II.
 It still supports Epson/IBM compatible 9 and 24 pin printers.  Select the
 printer you are using in the CHANGE CONFIGURATION option at the Main Menu.  It
 is important to select the right printer.  Sending laser printer output to an
 Epson style printer or vice versa will produce utter garbage!

>DEEP SKY OBJECTS: INTRO

 Starting with Ver. 3.0, Deep Space 3-D includes a large database of galaxies,
 nebulae, star clusters, and other non-stellar objects: the SAC or Saguaro
 database, to be precise.  The entire NGC catalog (minus non-existent objects,
 mere groupings of 5 or fewer stars, and objects labeled "Unverified Southern
 Object").  Many dark nebulae, IC objects, PK planetary nebulae, and other non-
 NGC objects are added.

 Why have a computer program plot galaxies, nebulae, and clusters on a map
 for you, when there are any number of excellent printed atlases which do the
 same job?  Comets and planets require orbit computations, but deep sky objects
 just sit there!  What then, is the rationale for maintaining a large computer
 database of deep sky objects?  Most people will not be taking their computers
 out observing with them.

 The first advantage is customization.  You can create maps to the scale
 you need for the task at hand, include only the objects you want as the focus
 of your attention, and place the center of interest at the center of the map!
-No more map border-hopping.

 Another advantage is the combination of the functions of an atlas and
 catalog.  This is a catalog with a graphical user interface!  As each object
 is identified on the map, the catalog information is displayed, allowing you
 to do intelligent pre-observation planning.

 As you label the objects they go into a cumulative observing list.  Plot maps
 of various parts of the sky to whatever level of detail you need, select the
 objects that will be your targets for the evening, and print out both your
 custom star atlas for the evening and a complete observing list, with catalog
 data, your own previous observing notes, and rise-set information for each
 object.

 At your observing site you can take observing notes right on your map!
 Star charts are no longer sacred objects to be protected from dew and ink.
 They can be used and thrown away, or better yet, saved in a notebook as part
 of your permanent observing record.  If you find a convenient star-hopping
 route to your target, sketch it right on the map.  If you are unable to see an
 object in your telescope after positively identifying the field of view, cross
 it out and make a note to that effect.  If you think you have discovered a
-comet or a nova, sketch its position right on the chart.

 Coming home from a night's observing, enter your comments directly into
 the database.  Select the objects that were particularly interesting and set
 up your own personal categories.

 Transfer your observing notes to the database either from the star map or the
 OBSERVING LIST option at the MAIN MENU.  Let Deep Space 3-D become your
 observing log.  Every time you reference an object your notes will be right
 there along with the basic data about the object to remind you of your night
 under the stars.

>ADDING DEEP SKY OBJ'S

 To add non-stellar deep sky objects to a star map type <Shift><F1>.  (The
 <Shift> key by itself will switch the function key menu.)

 The first question is whether the objects to be selected will be appended
 to the existing observing list or whether a new observing list will be
 created.  Start a fresh observing list for any given observing session, then
 append to it as you select objects from different parts of the sky.

 Select the limiting magnitude for non-stellar objects.  This selection is
 independent of the limiting magnitude for stars.  Only dark nebulae bypass the
 magnitude screening.  What magnitude you select will depend on the size of
 your telescope, the darkness of your observing site, and your observing
 experience.  The Messier list goes down to about 11th magnitude.  A 12 inch
 telescope with dark skies will take you a little past 13 for galaxies.
 Magnitude is not a rigid criterion of visibility.  Some objects are bright,
-but hard to see because they are large and their surface brightness is low.

 If you are a registered user, you may select objects from the entire database
 or from more specialized categories.  If you have an unregistered program you
 will be limited to the Messier list, or user-defined categories limited to
 subsets of the Messier list.  (The data is there, it just can't be accessed
 for mapping without a valid registration imprint.)  The Messier list is a good
 starter list of many of the brighter objects.  The "Herschel 400" list is the
 basis of an observing program sponsored by the Astronomical League.  It picks
 up the bright objects Messier missed and includes some of the more challenging
 objects in the NGC. If you are working on a Messier Marathon or working toward
 a "Herschel Club" certificate, Deep Space 3-D is made to order for your needs.
 You may also define up to four categories of your own. The categories you
 define can be totally arbitrary: "My Favorite Galaxies", "Objects I Can See
 From My Back Yard", "Planetary Nebulae That Don't Simply Look Like Stars",
 etc.

 Finally you can select within a category for the type of objects you want
 to observe.  Use the <Enter> key or <Arrow> keys to move the selection bar,
 and type <Space> to select an object type.  You may choose one, all, or any
 combination of object types.

>LABELING DEEP SKY OBJ'S

 Once deep sky objects are displayed, they may be screened individually and
 labeled with the primary or secondary name, deleted, or left on the screen
 unlabeled.  Objects that are labeled are thereby selected for the current
 observing list.  Objects may be selected one at a time using the cursor, just
 as stars are identified.  You may also cycle through the objects automatically
 by typing <Shift><F3>.  As an object is identified a small box is displayed
 that indicates the approximate size the label will be on the printout.  It may
 be positioned with the arrow keys, or the arrow keys in combination with the
 <Shift> key.  A line connecting the object with its label allows you to
 clearly identify objects even in cluttered areas of the sky.

 Along with the label, three windows will pop up.  One is a menu for the
 function keys, one is a summary description of the object, and the third,
 which is initially blank, is space for your observing notes.  You can scroll
 the description window with the <PgUp>, <PgDn>, <Home>, and <End> keys.

 If you want to add an object to a user-defined category, enter the description
 box with the <F1> key, position the cursor on one of the category labels, and
 type the space bar.  Typing the <Space> bar again will remove the object from
 the category.

>OBSERVING LIST

 The OBSERVING LIST option at the main menu allows you to browse the current
 observing list on the screen, add notes, delete objects from the list, print
 the list, save it as a named file to be called back later, or send it to an
 ASCII file allowing it to be accessed by a word processor.  Because multiple
 observing lists may be saved and recalled, they could be used in a similar way
 to the user-defined object categories.

 The Observing List Browse Function prints out the catalog description of the
 object, an optional rise/set graph, and optionally, any observing notes from
 the log file.  If rise/set graphs are included, the hours of darkness and
 twilight will be presented at the top of each page.

 Because of the amount of material to be printed about each object you may want
 to edit the observing list before printing it out.  You can omit the observing
 notes, the rise/set graph, or both by the "Configure Listing" option or you
 can send the output to an ASCII file and edit it with a word processor.

>OBJECT CATEGORIES

 User defined categories of deep sky objects are created or deleted from the
 OBJECT CATEGORIES option selected at the MAIN MENU.  Once a category is
 created, items can be added to the list one at a time from a star map, as
 described above, or by dumping an entire observing list into the category.
 For instance, you can create a category of "Barred Spiral Galaxies" by
 plotting a series of maps, adding galaxies down to whatever magnitude limit is
 desired, cycling through the naming/selection process, deleting all galaxies
 except the SB type.  By simply labeling the barred spirals you add them to the
 current observing list.  Now go back to the main menu, create a "Barred
 Spiral" category, and dump the observing list into the category.  As you run
 across other barred spirals they can be added to the list one-by-one.  Objects
 being added to a category are screened by the program, so there is no danger
 of duplication.

 Once a user-defined category has been established, it may be browsed from
 the main menu OBJECT CATEGORIES option.

>OBSERVING NOTES

 Notes may be added to the observing log when an object is selected on a
 map by the cursor, during the naming cycle, or from the OBSERVING LIST or
 OBJECT CATEGORIES options at the MAIN MENU.  If you are returning from an
 observing session the easiest way to do this is to display the current
 observing list using the <Shift><F2> key.  When the objects are displayed,
 enter the naming cycle by typing <Shift><F3> and cycle through the list until
 the object of interest appears.  Type <F1> twice to get into the log window.
 A cursor will appear in the log window and any text you type in will appear.

 The log window operates like a highly simplified word processor.  To
 delete text you can delete one character at a time with the backspace key or
 mark a larger region for deletion using the <Del> key.  Mark the starting and
 ending points for deletion with the <Del> key, then type <Enter> or <Esc> to
 complete the deletion and exit deletion mode.

 Insertion at the end of the text is automatic.  Just type.  To make
 insertions elsewhere in the text, move the cursor to the point of insertion
 and type the <Ins> key.  This will open up a space for insertion.  End the
 insertion by typing the <Esc> key.  This will close up the space that was
-created upon entering insertion mode.

 If you have more to say than will fit in the window, just keep typing.
 The window will scroll.  You can maneuver around the text area with the
 <Home>, <End>, <PgUp>, <PgDn> and <Arrow> keys.

 You can leave the log window by typing <F1> or <Esc>.

>ABBREVIATIONS

 The NGC (New General Catalog of non-stellar objects), Burnham's Celestial
 Handbook, and other sources have used a series of abbreviations for verbal
 comments on objects.  These abbreviations have been carried over into the
 SAC database and appear in the notes section of the basic information window.
 They take a little practice to read fluently.  Here they are:

 !    remarkable object                  diam diameter
 !!   very remarkable object             dif  diffuse
 am   among                              E    elongated
 att  attached                           e    extremely
 bet  between                            er   easily resolved
 neb  nebula, nebulosity                 F    faint
 B    bright                             f    following
 b    brighter                           g    gradually
 C    compressed                         iF   irregular figure
 c    considerably                       inv  involved
 Cl   cluster                            irr  irregular
 D    double                             L    large
 def  defined                            l    little
 deg  degrees                            mag  magnitude
-                        (Continued)

 M    middle                             S    small
 m    much                               s    suddenly
 n    north                              s    south
 N    nucleus                            sc   scattered
 neb  nebula, nebulosity                 susp suspected
 P w  paired with                        st   star or stellar
 p    pretty (before F,B,L or S)         v    very
 p    preceding                          var  variable
 P    poor                               nf   north following
 R    round                              np   north preceding
 Ri   rich                               sf   south following
 r    not well resolved, mottled         sp   south preceding
 rr   partially resolved                 11m  11th magnitude
 rrr  well resolved                      8... 8th magnitude and fainter
                                         9...13  9th to 13th magnitude

 (Other Abbreviations:
 P w N ( paired with NGC###)
 P w U ( paired with UGC ###)

>OBJECT CLASS

 Each object type has its own classification system.  Here are the classes used
 in the descriptions of open clusters, globular clusters, planetary nebulae,
 and galaxies.  (Adapted from the SAC database documentation.)

 Open Clusters:  Trumpler type

   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 range   2.  Moderate range   3.  Large range

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

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

 Globular Clusters:  Shapley-Sawyer concentration rating

   Globular clusters are rated on a scale of 1 to 12:
     1 = very concentrated,  12 = not concentrated


 Planetary Nebulae:  Vorontsov-Velyaminov type

   1.  Stellar
   2.  Smooth disk (a, brighter center; b, uniform brightness;
                    c, traces of ring structure)
   3.  Irregular disk (a, very irregular brightness distribution;
                    b, traces of ring structure)
   4.  Ring structure
   5.  Irregular form similar to diffuse nebula
   6.  Anomalous form, no regular structure

-  (Some complex forms may combine two types.)

 Galaxies:  Hubble classification

   E  Elliptical Galaxy:
        E0 is spherical -- E7 is highly flattened
        Subgroups; 'd' (dwarf), 'c' (supergiant), 'D' (diffuse halo)

   S  Spiral Galaxy:
        Sa: tightly wound arms
        Sb: moderately wound arms
        Sc: loosely wound arms

   SB Barred Spiral Galaxy:
        SBa: tightly wound arms
        SBb: moderately wound arms
>