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oEk|'û░Ç╦FàHGEOCLOCK (TM) 4.3, 91/06/08, (C) 1991 Joseph R Ahlgren, BBS 703-241-7980Help Master Menu 1.  Getting Started
 2.  About...
 3.  Commands 4.  Advanced Topics 5.  HAM package 6.  Registering 1.1  GEOCLOCK Files 1.2  Initial Setup3 1.3  Configuring for EGA/VGA/SVGA Graphics Systems1 1.4  Configuring for Monochrome Graphics Systems$ 1.5  Configuring for Your Time Zone 1.6  City Locations on Maps 1.7  Configuring for Your City) 1.8  Finding Your Latitude and Longitude 1.9  Mouse- 1.10 Editing ASCII Files with the TED Editor 1.11 Common Problems 2.1  About GEOCLOCK 2.2  About Time Zones 2.3  About Sunrise and Sunset 2.4  About the Terminator" 2.5  About Latitude and Longitude 3.1  Command Summary 3.2  Help Control 3.3  Map Selection 3.4  Map Annotation 3.5  Time Control and Display 3.6  Map Display 3.7  Sun Display Control# 3.8  Time, Zone and Format Control 3.9  Special Commands 3.10 Color Control 3.11 Graphics Control" 3.12 Zoom (registered users only)2 3.13 Distance Measurement (registered users only)* 4.1  City Name Placement and Time Display 4.2  Colors and Default Colors  4.3  Changing GEOCLOCK Defaults( 4.4  Calendars and Daylight Saving Time! 4.5  Ephemeris Data and Accuracy 4.6  Software structure 4.7  Map Generation System 5.1  HAM package features 5.2  Starting the HAM package 5.3  Call Sign Analysis$ 5.4  Use of other GEOCLOCK features 5.5  Twilight zone definition 5.6  HAM data base
 5.7  Support" 5.8  Call Sign Analysis Algorithm
 6.1  Updates 6.2  Available Maps' 6.3  About the GEOCLOCK Bulletin Board 6.4  GEOCLOCK special pricing 6.5  Ordering GEOCLOCKIUse the up and down arrow keys to select the topic of interest.  PressingHENTER will display a menu of detailed topics, while pressing ESCAPE willDreturn to GEOCLOCK.  If you are new to GEOCLOCK, you should read theH"Getting Started" section.  As you become familiar with the program, youJshould browse through the other topics to learn about the GEOCLOCK options
and features.IUse the up and down arrow keys to select the topic of interest.  PressingKENTER will display information about that topic.  Press ESCAPE to return toHthe main help menu.  If you are new to GEOCLOCK, you should read all thetopics listed here.VHThese topics provide information about GEOCLOCK and the astronomical andgeographical "facts of life."░JGEOCLOCK has a large number of commands control the display.  This section1contains a description of each available command.DThese are topics of interest only to advanced users or are topics ofspecialized interest.╚I  The HAM package is an add-in to the registered version of GEOCLOCK.  ItIsupports a variety of features to support HAM, SWL, and DX operators, andEincludes a custom Equidistant-Azimuthal (Great Circle) projection mapcentered on your location.JGEOCLOCK is distributed as shareware. This means that if you use and enjoyJthe program, you are expected to register it.  See "Ordering GEOCLOCK" forKdetails.  Registering your copy makes continued improvement and support forJGEOCLOCK possible.  Furthermore, the registered version includes the zoom,Idistance measuring, and city time display functions, plus many additionalDmaps.  You also get access to additional map files from the GEOCLOCKBulletin Board.}B  The following describes and identifies the files associated with	GEOCLOCK.I  GEOCLK43.ZIP contains the EGA/VGA/SVGA version of GEOCLOCK, three maps,D  this help file, and two data files to help you get started in cus-  tomizing the program.&GEOCLK.EXE        EGA/VGA/SVGA program!GEOCLOCK.HLP      Help files text"MAP1.EGA          Map of the world&MAP2.EGA          Map of the 48 states,MAP2000.EGA       North polar projection mapGGECONFIG.DAT      Text file with time zone and other configuration data9GEOCLOCK.DAT      Text file with default map overlay dataI  GEOMNO43.ZIP contains the CGA/Hercules/MCGA/AT&T 640x440/PC3270 versionJ  of the program, plus the extra files and utilities needed to convert theG  files in GEOCLK43.ZIP to the proper format.  To run this version, youH  need BOTH GEOCLK43.ZIP (all files except GEOCLK.EXE) and GEOMNO43.ZIP.!GEOMNO.EXE        CGA etc program:GEOCONVT.EXE      Program to convert maps to GEOMNO format'*.FON             Files to define fonts**.BGI             Files to define graphicsI  The registered version of GEOCLOCK includes these files, plus many mapsE  files, customization files for each map, and some utility programs.<Five types of data files are used while GEOCLOCK is running:GECONFIG.DATJ  This text file contains the data to configure GEOCLOCK for your system. F  It has information about your graphics system, all time zone defini-H  tions, your local time zone, and any commands you want to establish as  defaults.GEOCLOCK.DATJ  This text file contains the default overlay data for all GEOCLOCK maps. I  The first line in this file gives the local time zone.  The second lineJ  gives the latitude, longitude, and city name for the primary city (i.e.,J  the city listed in the map legend).  Subsequent lines give the names and,  locations of other cities to be displayed.GEO*.DATJ  * is any integer. These text files contain similar data to GEOCLOCK.DAT,I  including a primary city for the map, but the data apply only to MAP*. D  For example, GEO3.DAT contains the data for MAP3.  If a map has noH  corresponding GEO*.DAT file, cities and other data in GEOCLOCK.DAT areH  used instead.  These files can also contain other commands for display  on the indicated map.MAPn.*G  These binary files contain the maps.  The extension (*) indicates theJ  map format.  EGA is for EGA, VGA, and SVGA maps.  CGA is for CGA, HGC isH  for Hercules, MCG is for MCGA, ATT is for AT&T 640x400, and 327 is forJ  PC3270.  By convention, map numbers (n) have the following designations:D        1 - 1999   640x350 (EGA) resolution  (Only these maps can beD                   converted for display in the monochrome version.)G     2000 - 2999   Polar or other large area non-rectangular projection&     3000 - 3999   Small area city map+     4000 - 5999   640x480 (VGA) resolution,     6000 - 7999   800x600 (SVGA) resolutionB     9000 - 9999   Azimuthal-equidistant (great circle) projection
SELEC*.FILI  This file contains the map directory used for the map selection (S) andBZoom (Z) functions.  The * is the same as for MAPn.* (for example,ESELECEGA.FIL for EGA).  It is built automatically by GEOCLOCK, and isKautomatically changed each time you add a map to your directory or delete amap.  ²G  GEOCLOCK requires a hard disk, a minimum of 200K available RAM (up toK250K to use VGA and Super VGA (SVGA) (800x600) modes, and up to 350K to use5the HAM package), and a graphics adapter and monitor.K     There are two versions of GEOCLOCK.  The color version is contained inJGEOCLK43.ZIP and is designed to support computers with a 256K EGA, VGA, orDSVGA boards with a compatible color monitor.  The monochrome versionGrequires both GEOMNO43.ZIP and GEOCLK43.ZIP, and is designed to supportJCGA, Hercules, MCGA, AT&T 640x400, and PC3270 graphics, all in the highestGresolution monochrome mode available for that card.  To get the programrunning, do the following:I  1.  Un-ZIP GEOCLK43.ZIP (and GEOMNO43.ZIP if required) to the directoryIyou will run from.  It is best to have a directory dedicated to GEOCLOCK.I  2.  Set up the program for your graphics adapter.  See "Configuring forYour Graphics System."D  3.  Customize GEOCLOCK for your location and time zone.  See "Con-=figuring for Your Time Zone" and "Configuring for Your City."H  4.  If you are a registered user, you need to run the REGISTER programto enable the special features.G  5.  Run the program.  Enter GEOCLK (for EGA, VGA, and SVGA) or GEOMNOJ(for the other adapters), and the program will start.  The F1 key provides(help, and Escape terminates the program.╚;The color version of GEOCLOCK supports 3 graphics adapters:4   256K enhanced graphics adapter (EGA) (640x350x16)8   VGA (built-in on the IBM PS/2 model 50+) (640x480x16)   800x600x16 color super VGAIVGA mode is the default for the color version.  If you have a VGA monitor:and graphics card, you do not need to do anything further.H   If you have an EGA, you should use a text editor to add the followingKline to the GECONFIG.DAT file.  This command locks out maps files which are#not compatible with an EGA monitor:EGAJ   If your have SVGA, you should add the appropriate SVGA command for yourHgraphics adapter, as listed below, in your GECONFIG.DAT file.  WARNING -Jyou can damage your monitor if you do not have a multisync monitor and tryto use the SVGA mode.SVGA24        Tecmar VGA/ADHSVGA41        VEGA VGA, Orchid, STB, Genoa, Sigma, Allstar Peacock (VGA)"SVGA41        Tseng ET4000 chipsetSVGA71        AT&T VDC600%SVGA82        Oak Technologies VGA-16(SVGA84        ATI EGA Wonder, VGA Wonder6SVGA88        Paradise VGA, AT&T VDC600, AST VGA Plus,:SVGA88        Compaq VGA, Dell VGA, Hewlett-Packard D1180A'SVGA91        Maxxon, SEFCO TVGA, Imtec$SVGA94        Logix, ATI Prism Elite4SVGA98        VEGA VGA, Tatung VGA, Video7 V-RAM VGAGSVGA106       VESA standard interface, Ahead B, Genoa 6400, Zymos PoachSVGA112       Cardinal'SVGA112/2     Everex Micro Enhancer EGASVGA113       NSI Smart EGA+&SVGA28421/98  Video7 VGA, VEGA Ext EGAIYou can use any text editor for this.  If you use the TED editor includedKwith GEOCLOCK (see HELP 1.10), enter the following at the DOS command line:TED GECONFIG.DAT XFwhere X is the appropriate graphics designator -- either EGA or SVGA**GIf your adapter is not listed, check with your board supplier or user'sGmanual. The syntax is SVGAa/b/c/d, where a, b, c, and d are the decimalJvales of the AX, BX, CX, and DX registers to enter the 800x600x16 graphicsmode by executing INT 10.╘@The monochrome version of GEOCLOCK supports 5 graphics adapters:-   Color graphics adapter (CGA) (640x200 B&W)   Hercules (720x348 B&W)6   MCGA (built-in on IBM PS/2 25 and 30) (640x480 B&W)   AT&T (640x400 B&W)   PC 3270 (720x350 B&W)KWith this version, you must execute the configuration program to adapt your@maps for your graphics adapter.  At the DOS command line, enter:
GEOCONVT *Iwhere * corresponds to your graphics adapter (CGA, HGC, MCG. ATT, or 327)IAll maps in the directory will be converted to the proper format for yoursystem.IIMPORTANT: The monochrome version of GEOCLOCK has many limitations and isno longer supported.ΦJ     GEOCLOCK has a comprehensive system for handling all known time zonesKin the world.  The GECONFIG.DAT file contains definitions of all time zones4and daylight saving time systems identified to date.K     These definitions include the dates for switching between standard andGsummer time (for example, 91/04/07 and 91/10/27 for most of the U.S. inJ1991), the common names for standard and summer time (for example, EST andCEDT), and a codename to refer to the definition (for example, ET). GOrdinarily, you should not need to change these definitions.  Each time%zone is preceded by the keyword ZONE.G     To make sure that GEOCLOCK gives the proper sun position, you mustItell GEOCLOCK what time zone your PC's clock uses.  (For most users, thisBwill be the time zone in which you live.)  This is done by editingEGECONFIG.DAT (use TED if you do not have a favorite ASCII editor) andKadding the proper PCZONE command.  This command should be placed at the end)of the GECONFIG.DAT file.  The format is:PCZONE  codenameGwhere codename is the codename for the time zone, as listed in the ZONE<commands.  There should be no other characters on this line.    Some common codenames are:&ET      Eastern Standard/Daylight Time8EST     Eastern Standard Time all year (most of Indiana)&CT      Central Standard/Daylight Time'MT      Mountain Standard/Daylight Time1MST     Mountain Standard Time all year (Arizona)&PT      Pacific Standard/Daylight TimeAKT     AlaskaHST     HawaiiUKT     United Kingdom, Ireland"+1A     Most of continental EuropeJ    GEOCLOCK is normally distributed with the four major time zones in theJcontinental U.S. and Canada at the end of GECONFIG.DAT.  You need not editEthe file if you live in the Eastern time zone.  Otherwise, you should)delete the three zones that do not apply.H    For example, if your PC's clock is on Pacific Time, the last line ofGECONFIG.DAT should be:	PCZONE PTG    If you live outside of these four time zones, you should delete allJfour lines and substitute the codename for your location.  For example, if=you live in England, the last line of GECONFIG.DAT should be:
PCZONE UKT\I    GEOCLOCK has great flexibility in displaying cities on the maps.  ForJmost maps (e.g., MAP2) there is a corresponding text file (e.g., GEO2.DAT)Jthat contains the customization information for that map.  GEOCLOCK.DAT isCused for MAP1, and any other map that does not have a correspondingGEOn.DAT file.F    The first line of any GEOn.DAT file is the time zone codename thatJdetermines which time zone will be used for time display on that map.  ForHexample, ET indicates Eastern time, and CT indicates central time.  (SeeI"Configuring for Your Time Zone.")  This should normally be the time zoneGcodename for the first city listed (the second line of the file).  ThisJcity is the "primary" city for the map.  The rest of the lines in the file@specify the names and locations of other cities to be displayed.E    The format for display of a city is   "Latitude Longitude Name". HEither decimal degrees or degrees minutes seconds (DMS) may be used.  InFthe decimal degree format, the minus sign (-) indicates south latitudeK(south of the equator) and west longitude (in the western hemisphere).  ForIDMS format, separate entries by an "x", and place the direction indicatorGat the end.  For example, 31 degrees 15 minutes west longitude would beD31x15W in DMS, and -31.25 in decimal, while 45 degrees 12 minutes 38Iseconds north latitude would be 45x12x38N in DMS and 45.2106 in decimal. !Some examples of these lines are:!  34.00     -118.25   Los Angeles  30x3N     31x15E    Cairo"  -26.17    28.03     Johannesburg$  27x49N    85x21E    Katmandu NepalJ    The first city listed in a file is the "primary" city.  It is used forKthe astronomical calculations which are normally shown at the bottom of theJmap.  The sunrise and sunset time, azimuth and elevation to the sun, localKtime, and the sun's sub point (the point on earth where the sun is directly-overhead) can be displayed for this location.0I    You will probably want to customize the display by entering cities ofGyour choice on some maps.  In particular, you may want to make the cityHwhere you live the "primary" city on one or more of the maps.  This willHgive sunrise and sunset, plus other sun-related data for you city on the lines at the bottom of the maps.E    To install your city as the primary city in a GEO*.DAT file, (forDexample, GEO2.DAT), edit the file at the DOS command line (e.g., TEDIGEO2.DAT).  You can use any ASCII text editor, but TED is especially easyKand is supplied with GEOCLOCK (See HELP 1.10).  Using the cursor and editorHkeys, replace the first line of the file, if necessary, so that the timeKzone codename corresponds with your time zone.  Then position the cursor atFthe end of the first line and press "Enter".  This will create a blankHsecond line.  Next, enter your latitude, longitude, and location name onFthe second line.  Finally, press F7 to save these changes.  (See "CityGLocations on Maps" (1.6) for details on entering the latitude/longitudedefinitions for cities.)J     Repeat this for every map you want to change.  It is not necessary to<change all the files, or to use the same city in every file.C     For example, here is part of the GEO2.DAT file that comes with	GEOCLOCK:                    ET     38.90   -77.03 Washington     33.75   -84.38 Atlanta     42.33   -71.08 Boston	     ....K     Suppose you live in Cedar Rapids, Iowa and want Cedar Rapids to appearHas the primary city on one or more maps.  The first step is to determineFyour latitude and longitude (see "Finding Your Latitude and Longitude"G(1.8)).  Next, use the TED editor that came with GEOCLOCK, or any otherHtext editor, to edit the GEOn.DAT file corresponding to the map file youJwant to change.  For example, to change MAP2 (the US map), edit GEO2.DAT. GIf you use TED, just enter TED GEO2.DAT.  Change the first line to yourJtime zone, if necessary.  Cedar Rapids is in the Central time zone, so useFthe editor to change ET to CT.  Next, make Cedar Rapids the first cityHlisted.  In this case, it is 41.98N and 91.64W.  Adding this data to theGEO2.DAT file gives:                    CT      41.98   -91.64 Cedar Rapids     38.90   -77.03 Washington     33.75   -84.38 Atlanta     42.33   -71.08 Boston	     ....J    If you want Cedar Rapids to appear on a map, but do not want it as theKprimary city, enter its latitude, longitude, and name in the list of cities2on the GEO*.DAT file, but not as the first city.  oK     Accurate lat/long are essential for proper display of cities on a map,Jand also for accurate sunrise and sunset times of a map's "primary" city. FAn error of one degree of longitude changes sunrise and sunset by fourKminutes.  The easiest way to find a particular latitude and longitude is toKlook it up in an atlas.  The next easiest way is to call your local airportHor weather bureau for the information.  You can also leave a request forKinformation on the GEOCLOCK Bulletin Board, and you should get a reply in a
short time.  xJ     Most GEOCLOCK operations are controlled from the keyboard, and do notJuse a mouse.  However, the [D]istance and [Z]oom functions (available onlyGto registered users) use a graphics cursor which can be operated eitherfrom the keyboard or a mouse.F     To use the mouse, the INT 33 driver must be loaded.  This driver,Jwhich comes with most mice, is usually called MOUSE.COM or MOUSE.SYS.  The:mouse buttons and functions match the keyboard as follows:?    Left Mouse Button           Control (CTRL) and Page-Up keys:    Center Mouse Button         Escape (ESC) Key and Enter       (if available)B    Right Mouse Button          Alternate (ALT) and Page-Down keys:    Mouse Motion                Arrow and Shift-Arrow keysG     All the keyboard functions work, even if a mouse is activated.  InIparticular, the arrow keys may be used to "fine-tune" the cursor positionKafter the mouse has moved the cursor to the vicinity of the desired point. KThe Escape or Enter key is used for all of its functions if your mouse doesnot have a center button.╛J     Customizing GEOCLOCK requires editing the various GEO*.DAT file.  AnyGASCII text editor can be used.  If you use a word processor to edit theKfiles, be sure to save the files in ASCII (DOS text) format rather than theword processor's format.K     The public domain editor TED (Tiny EDitor) is supplied with GEOCLOCK. IIt is a simple text editor, perfect for customizing these text files.  ToIedit a file (for example, GEOCLOCK.DAT), enter TED <file name> at the DOSprompt.  For example:TED GEOCLOCK.DATIThe file will appear on the screen, with a function key reminder block atGthe bottom.  The arrow and other cursor positioning keys can be used toKmove the cursor around the file.  The delete, insert, and other keys can beGused to change the text in the file.  Five function keys are especiallyhandy:3F1    ABORT      Exit editor without saving changes=F7    EXIT       Exit editor and save changes in ASCII format2F8    DEL EOL    Delete from cursor to end of lineF9    DEL L      Delete lineF10   UDEL L     Undelete lineSI1 The sun is not in the right place.  This is usually caused by your PC'sG  system clock not being set to the correct time, or a wrong or missingJ  PCZONE command in the GECONFIG.DAT file.  See "Configuring for Your TimeF  Zone."  GEOCLOCK is initially set to assume your PC is in Eastern US  time.F2 Your home town is not displayed, or your local time zone is not dis-J  played.  The world and U.S. maps in GEOCLOCK (Maps 1 and 2) are initial-F  ly configured for Eastern Time and Washington DC.  The first line ofI  every GEO*.DAT file gives the time zone to display.  The second line ofG  each GEO*.DAT file gives the latitude, longitude, and city name to beE  displayed at the bottom of the screen.  Use an ASCII text editor toJ  change the GEO*.DAT files for your situation.  See "Configuring for Your%  City" and "City Locations on Maps."H3 The characters are not displayed correctly. Some EGA boards, includingH  the Zenith, do not properly support the IBM standard. If you have thisF  problem, load the program FONT8P14.COM before you run GEOCLOCK. ThisE  program is installed as a TSR and so only needs to be run after theG  computer is turned on or rebooted. This program is available from theI  GEOCLOCK Bulletin Board, and is included with the registered version of  the program.G4 The screen blinks.  This is a problem on some EGA and VGA boards withG  the Trident chip set.  Add the FLICKER and/or NOBLINK commands to the  GECONFIG.DAT file.I5 There is no color on CGA or MCGA. That is correct. The color capabilityJ  of these modes is too limited for GEOCLOCK. The program uses the highestG  resolution 2 color mode instead of the lower resolution 4 color mode.D6 The maps and other data are hard to see on a grey scale or LCD VGAJ  system.  GEOCLOCK is configured to look best on a full color VGA or EGA.G  Add the following lines to GECONFIG.DAT to adjust the colors for good  grey scale appearance:  COLOR00307  COLOR10902  COLOR20228  COLOR31806┬E     "It's inconceivable that you won't like this program."  -- JerryPournelle, BYTEJ     GEOCLOCK shows the current time (based on your computer's clock) withHa high quality map of the earth.  The current sun position is displayed,Jand the parts of the earth in sunlight and twilight are highlighted.  ThisKdisplay is automatically updated every few seconds.  Local sunrise, sunset,Dthe sun's azimuth and elevation, and times around the world are alsoKdisplayed.  A variety of map backgrounds and other options are available. A.graphics adapter and a hard disk are required.F     GEOCLOCK is primarily an EGA-VGA-SVGA program operating in the 16Hcolor mode.  There is also a monochrome version for CGA, Hercules, MCGA,HAT&T 640x400, and PC3270.  This version has many limitations and has notKbeen enhanced since version 3.4, except to remain compatible with the colorversion.J     GEOCLOCK is distributed as shareware.  This means that if you use andBenjoy the program, you are expected to register it.  See "OrderingJGEOCLOCK" for details.  The registered version includes the zoom, distanceAmeasuring, and city time display functions, and at least 25 maps.HGEOCLOCK    Joseph R Ahlgren    2218 N Tuckahoe St    Arlington VA 22205:            BBS 703-241-7980         CompuServe 70461,2340╢F     Time zones are more complicated than most people think.  To beginKwith, they change with longitude, so that the sun is approximately overheadIat noon.  However, various political decisions based on uniformity, localJcustom, and how to handle daylight saving time (or summer time), have madeGtime zones very complex.  There are a number of changes every year, and8countries can change their time systems without warning.G     Data for all known time zones (about 95, including permutations ofJdaylight saving time) are distributed with GEOCLOCK.  They are included inthe GECONFIG.DAT file.J     To specify a time zone, several items or needed.  First, how the timeEzone relates to the standard time zone must be defined.  This zone isHvariously called Greenwich Mean Time (GMT) or Universal Time CoordinatedF(UTC) or Zulu Time (Z).  US Eastern Standard Time is five hours behindK(earlier than) GMT.  Next, the dates and times when the zone changes to andIfrom summer time must be defined.  US Eastern Time goes to summer time onKApril 7, 1991 at 0700 GMT, and returns to standard time on October 27, 1991Jat 0700 GMT.  Finally, names for the time zone and the standard and summerKtimes must be specified.  As an example, US Eastern Time from April 1991 toApril 1992 is specified by:CZONE   ET     EST     -5     EDT     -4     91/04/07:7   91/10/27:7JET is the name the time zone is referred to by all GEOCLOCK commands.  TheHdefinition states that the zone is called EST and is 5 hours behind GMT,Iexcept between 91/04/07 0700 GMT and 91/10/27 0700 GMT, when it is calledEDT and is 4 hours behind GMT.E     If the ZONE commands are not for the correct year, GEOCLOCK willGautomatically update.  This update is close but not always correct, andKcountries' summer time definitions can change.  Therefore, I recommend thatHthe ZONE commands be kept current. A GECONFIG.DAT file with current time6zone data is available on the GEOCLOCK Bulletin Board.K     The PCZONE command sets the relationship between the local time on theKPC's clock and GMT, i.e., declares which time zone the PC's clock is in. ItKtakes one parameter - a time zone code, as defined in the ZONE command. For*example, if you use Eastern Time, specify:	PCZONE ETJThis command is best used in the GECONFIG.DAT file, and it must follow theGZONE command that it references.  Thus, it is usually the last entry in
GECONFIG.DAT.  H     GEOCLOCK calculates the sunrise and sunset times for your location.@The times are usually within one minute of local newspaper data.K     The precise moment of sunrise or sunset is difficult to determine.  ItFdepends not only on the position of the Earth and sun, but also on theKterrain near you (it appears to rise later from behind a mountain than fromJthe sea), and on the earth's atmosphere.  Another complication is that theIsun appears quite large, and takes about two minutes to shift position byJits own diameter.  All these factors together mean that even at sea level,Ethe sun appears to just break above the horizon when it is in reality$almost one degree BELOW the horizon.K     By default, GEOCLOCK uses the value of 0.833 degrees below the horizonGto compute sunrise and sunset.  This agrees well with observed times atJmoderate latitudes and flat terrain.  The SUNANGLE parameter, which is theCangle GEOCLOCK uses for the sunrise and sunset calculations, can be1adjusted to correspond to your local conditions. √H     The terminator is the boundary between day and night.  Its positionKchanges during the day (it makes a complete circuit around the Earth in oneEday), and it also changes during the year.  Daylight is longer in theJnorthern hemisphere than in the southern hemisphere from about March 21 toISeptember 21, and daylight is longer in the southern than in the northernIhemisphere during the rest of the year.  You can see the changes by using&the time control features of GEOCLOCK.J     The terminator more or less divides the Earth into halves: facing theJsun and facing away from the sun.  Like sunrise and sunset times, the pre-Hcise location of the terminator is hard to define.  By default, GEOCLOCKEshows the optical terminator, which corresponds to visual sunrise andKsunset.  The SUNLIGHT command can be used to control the precise terminatorEposition.  If it is set to the same value as SUNANGLE, the terminator,position will agree with sunrise and sunset.G     GEOCLOCK also shows the twilight terminator.  By default, GEOCLOCKIuses -6°, which corresponds to the civil definition of twilight: the timeCwhen it is so dark that you must use your headlights.  The TWILIGHTGparameter is used to control the precise definition of this terminator.╨J     Every point on the Earth's surface has an address.  The first part ofHthe address is the latitude, which is the distance north or south of theGequator.  The second part of the address is the longitude, which is theKdistance east or west of a line going from the north pole to the south poleIthrough Greenwich, England (this is called the Greenwich meridian). Since?the Earth is a sphere, these distances are expressed as angles.I     There are several ways to express these angles. The first system wasIinvented by the Babylonians about 5000 years ago.  It divides angles intoI360 degrees (°), each degree into 60 minutes ('), and each minute into 60Cseconds (").  The Washington Monument is 38° 53' 21.5" north of theGequator, and 77° 2' 8.0" west of the Greenwich meridian in this system.HThis location is accurate to about 60 feet, or 0.5 seconds. GEOCLOCK can<use this system.  For example, the Washington Monument is at38x53x21.5N  77x2x8.0WK     A more modern system gives these same angles as decimal degrees. NorthDlatitudes and east longitudes are positive, while south and west areHnegative.  GEOCLOCK can use this system also.  It is used for data filesFdistributed with GEOCLOCK.  For example, the Washington Monument is at+38.8893  -77.0356∞H    GEOCLOCK has a large number of commands which may be used to controlHthe display.  The commands consisting of a single letter (such as S) areKactivated by pressing that letter.  The other commands (such as MAP) may beKincluded in the configuration file, in a data file, on the GEOCLOCK commandFline, or entered interactively by pressing the P key while GEOCLOCK isdisplaying a map.I    The available commands are listed below. More detailed information isIavailable in other sections of Help.  Each group of commands listed below8is described in a separate section of this part of Help.I    Commands which concern color and graphics control do not apply to theKmonochrome version of GEOCLOCK (GEOMNO).  Some other commands have not been&implemented in the monochrome version.*** Help Control"HELP (or H)  Activates Help system"?            Activates Help system3F1           Function Key 1 - Activates Help system2REM          Remark - remainder of line is ignored*** Map Selection!S            Select map from list!MAP          Select map from list$MAPn         Changes to map number nNOMAP        No map displayed*** Map Annotation@FULL         City, sun rise/set, local time, sun position legendNONE         No legend#TIME         Local time only legend2SUN          City, sun rise/set, local time legend/HIDEMN       Do not display map name and number(SHOWMN       Display map name and number*** Time Control and Display)YEAR2        Show 2 digit year (e.g., 91)+YEAR4        Show 4 digit year (e.g., 1991)NOMONTH      Show month numberSHOWMONTH    Show month name$NODAY        Do not show day of weekSHOWDAY      Show day of week%NOSECONDS    Show time to last minute(SHOWSECONDS  Show time to nearest second)DST          Control Daylight Saving TimeZONE         Define time zone!PCZONE       Specify PC time zone*** Map Display,NOMARK       Do not display location markers%MARK         Display location markers&NOCITY       Do not display city namesCITY         Display city names@NOLINE       Do not display incremental latitude/longitude lines:LINE         Set lat/long line increment and display lines(TLINC        Set latitude line increment)GLINC        Set longitude line increment,GLSPEC       Display specific longitude line+TLSPEC       Display specific latitude line8CLINE        Clear all specific latitude/longitude lines2HIDELL       Do not show Latitude/Longitude values+SHOWLL       Show Latitude/Longitude valuesINCLUDE      Include data fileDRAWLINE     Draw line on map0VECTOR       Continue a line started by drawlineDRAWCIRCLE   Draw circle on map*** Sun Display Control$SUNANGLE     Sun rise/set definition"SUNLIGHT     Terminator definition+TWILIGHT     Twilight terminator definition"TLMASK       Twilight area patternNORMAL       Normal Display1REVERSE      Reverse Display (for LCD monochrome)&LIGHT        All sunlight is displayed%DARK         No sunlight is displayed%BLANK        Highlighting is not used!*** Time, Zone and Format ControlT            Set new timeF            Change time rate+U            Change display update intervalR            Reset time*** Special CommandsP            Enter a command-L            Return to previous map displayedD            Measure distance&Z            Select another map (Zoom)9FAST         Use reduced accuracy but faster calculations6SLOW         Use high accuracy but slower calculations0387          Activate speedup with 80387 or i486"HAMDB        Specify HAM data base"HAM          Activate HAM features$NOHAM        Deactivate HAM features6NOBLINK      Required for some Trident graphics boards6FLICKER      Required for some Trident graphics boards.QUIET        Does not beep on cycle completion&SOUND        Beeps on cycle completion*** Color ControlCSET         Color change menuCOLOR        Set color+MCOLOR       Set color for Distance cursors*** Graphics Control(EGA          Specify EGA graphics system(VGA          Specify VGA graphics system=SVGA         Specify 800x600 super VGA (SVGA) graphics system0SHOWVGA      Convert EGA maps to VGA for display:SHOWSVGA     Convert EGA and SVGA maps to SVGA for display*** Zoom (Z)*** Distance Measurement (D)╖"HELP (or H)  Activates help system"?            Activates help system3F1           Function Key 1 - Activates help systemF  The help system can be activated any time a map is displayed (exceptH  when Zoom or Distance is active) by pressing the ? key or function keyH  1. It can also be activated by entering HELP or ? at a command prompt.C  The top level menu of the Help system gives a list of a number ofE  topics. The selected topic is highlighted, and the selection can beI  changed by using the arrow keys. More details can be obtained about theJ  selected topic by pressing the ENTER key. The cursor keys, including theI  arrows, page up, page down, home, and end can be used to scroll throughH  the information. ESCAPE returns to the top HELP menu. The + and - keysG  select the next and previous topic without returning to the top menu.2REM          Remark - remainder of line is ignoredJ  Remarks can be used to document the various text files used to customize  GEOCLOCK.
Printing helpH  You can print the help information for a particular topic or print theG  entire help text.  To print a particular topic, bring up the detailedD  help screen for that topic and press ALT-P.  To print all the helpG  topics, bring up the help main menu screen and press ALT-P.  The menuH  will prompt you for a device name (LPT1 selects printer 1, but you canJ  print to any device or a file), and the number of lines printed per pageE  (select 0 for a laser printer, because laser printers automaticallyG  produce margins at the top and bottom of every page).  Finally, press8  ENTER to start printing, or ESCAPE to abort the print.╚!S            Select map from listG  Pressing this key displays a list of available maps.  The cursor keysF  can be used to select a specific map from this list.  Pressing ENTERE  displays the selected map.  The list is normally sorted in order ofD  decreasing size.  It can be sorted in alphabetic order of title by0  pressing T, or in numeric order by pressing N.!MAP          Select map from listI  This command works identically to S.  If it is included on the GEOCLOCKH  command line (for example, GEOCLK MAP), the selection menu will appear  before the program starts.$MAPn         Changes to MAP number nG  This command displays a specific map.  For example, MAP5 displays mapA  number 5.  If this command in included in GECONFIG.DAT, the map3  specified will appear as the first map displayed.NOMAPB  The map annotation and sun highlighting from the previous map is'  displayed without the map background.▓1Asterisks (*) indicate default values in GEOCLOCK@FULL *       City, sun rise/set, local time, sun position legendG  GEOCLOCK can display a time legend at the bottom of the screen.  FULLD  displays the full range of time and sun-related information on theH  legend.  This includes primary city name, its time and date, includingG  local time zone name, and sunrise and sunset time.  (The time zone isJ  the one specified in the corresponding GEO*.DAT file.)  It shows sunriseH  and sunset times for the primary city, the sun's subpoint coordinates,F  and the azimuth and elevation of the sun from the primary city.  TheH  format of the time and date can be controlled with other commands (see$  "Time, Zone, and Format Control").NONE         No legend#TIME         Local time only legend2SUN          City, sun rise/set, local time legend/HIDEMN *     Do not display map name and number(  Map number and name are not displayed.(SHOWMN       Display map name and numberH  The map number and name are displayed in the upper right corner of the9  map.  This is especially useful with the ZOOM function.á1Asterisks (*) indicate default values in GEOCLOCKE    GEOCLOCK displays time in a most significant to least significantHformat, i.e., year/month/day hour/minute/second.  The following commands/control the details of the time display format.9YEAR2 *      Show 2 digit year  (e.g., 91/05/01 12:14:45):YEAR4        Show 4 digit year  (e.g., 1991/05/01 12:14:450NOMONTH *    Show month number rather than name.ESHOWMONTH    Show month name rather than number (91 MAY 01 12:14:45).F  The standard 3 letter English abbreviations are used by default. TheJ  text for the month names can be specified by giving the 12 strings to be&  used for the 12 months. For example:;  SHOWMONTH JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC7NODAY *      Does not show display the day of the week.SHOWDAY      Show day of weekI  This command displays the day of the week (1991/05/01 WED 12:14:45). AsJ  in SHOWMONTH, the default is the standard 3 letter English abbreviation,#  but other names can be specified:%  SHOWDAY SUN MON TUE WED THU FRI SAT&NOSECONDS *  Shows time to last minute?  This command shows time to the last minute (1991/05/01 12:14)(SHOWSECONDS  Show time to nearest secondF  This command shows time to the nearest second (1991/05/01 12:14:45).)DST          Control Daylight Saving TimeI  The method GEOCLOCK uses to handle summer time when current data is notD  available in GECONFIG.DAT is close, but not perfect.  This commandE  specifies for which years the GEOCLOCK computed correction is to beF  applied.  By default, GEOCLOCK does not use summer time before 1980.5     DST is used to change this date.  The syntax is:  DST year1 year2E     Year1 is the earliest year in which to use summer time under theE  current specification, and year2 is the latest year in which to useB  summer time.  If year2 is omitted, there is no upper limit.  ForJ  example, DST 1950 specifies that summer time is to be used from 1950 on,C  while DST 1985 1995 specifies that summer time is to be used only  between 1985 and 1995.ZONE         Define time zoneC  This command defines a time zone: it relates the time zone to theC  standard time zone (variously called Greenwich Mean Time (GMT) orF  Universal Time Coordinated (UTC) or Zulu Time (Z)); it specifies theH  dates and times when the zone changes to and from summer time; and it H  names the time zone and the standard and summer times.  As an example,$  U.S. Eastern Time is specified by:E  ZONE   ET     EST     -5     EDT     -4     91/04/07:7   91/10/27:7G  ET is the name the time zone is referred to by all GEOCLOCK commands.I  The definition states that the zone is called EST and is 5 hours behindI  GMT, except between 91/04/07 0700 GMT and 91/10/27 0700 GMT, when it is'  called EDT and is 4 hours behind GMT.B  If the ZONE commands are not for the correct year, GEOCLOCK willH  automatically update them by changing each date to the closest date in;  the correct year which falls on the same day of the week.!PCZONE       Specify PC time zoneH  The PCZONE command sets the relationship between the local time on theJ  PC's clock and GMT, i.e., declares which time zone the PC's clock is in.C  It takes one parameter - a time zone code, as defined in the ZONE9  command. For example, if you use Eastern Time, specify:  PCZONE ETH  This command is best used in the GECONFIG.DAT file, and it must follow'  the ZONE command that it references. ╜1Asterisks (*) indicate default values in GEOCLOCK-NOMARK *     Do not display location markers.1MARK         Display location markers for cities.&NOCITY *     Do not display city namesBCITY         Display city names.  The city names and locations areD  contained in the corresponding GEO*.DAT file.  The name is usuallyI  displayed to the right of the location, but the name may be moved if itF  does not fit.  The location can be controlled by the user, and local*  time can be added (see Advanced Topics).4NOLINE *     Do not display latitude/longitude lines?  NOLINE removes all latitude/longitude lines from the display.:LINE         Set lat/long line increment and display linesG  This command enables latitude and longitude lines on the display, andH  sets the spacing between the lines. For example, LINE15 draws latitude!  and longitude 15 degrees apart.(TLINC        Set latitude line increment)GLINC        Set longitude line incrementH  TLINC and GLINC allow the spacing between latitude and longitude linesE  to be set independently. For example, TLINC 15 and GLINC 30 set theJ  latitude spacing to 15 degrees, and the longitude spacing to 30 degrees.#TLSPEC       Specific latitude line$GLSPEC       Specific longitude lineE  TLSPEC and GLSPEC allow specific latitude and longitude lines to beI  displayed.  For example, TLSPEC -67 draws a latitude line at 67 degreesG  south (the antarctic circle).  Up to 20 of these special lines can be  specified.8CLINE        Clear all specific latitude/longitude lines3  CLINE removes all special lines from the display.2HIDELL *     Do not show Latitude/Longitude values<  This command suppresses the latitude and longitude labels.+SHOWLL       Show Latitude/Longitude valuesI  This command labels all the latitude and longitude lines displayed. TheH  labels appear on the top and left edges of the display. The labels may  overlap other data."INCLUDE (or I)   Include data fileJ  When contained in a GEOn.DAT file, INCLUDE <file>  suspends reading fromF  the file being processed, and processes all commands in the <file>. J  When all commands in that file have been processed, reading resumes fromJ  the original file.  INCLUDE may be nested up to ten levels.  INCLUDE mayG  also be used in response to the "P" command.  In this case, the namedC  file will be included at the end of the GEOn.DAT file for the map  currently displayed.G    The effect of the INCLUDE command will be negated when a new map isH  selected or a new file is specified with INCLUDE.  The INCLUDE command-  can be abbreviated by I (i.e., I DATELINE).!DRAWLINE         Draw line on mapJ  DRAWLINE lat1 long1 lat2 long2 color   draws a line between (lat1,long1)G  and (lat2,long2) on the current map.  Color is the color in which theH  line will be drawn.  See "Color Control" for an explanation of the use@  of color.  If omitted, color defaults to 5 (yellow).  Example:#  DRAWLINE 38.9 -77.0 34.0 -118.3 0@  draws a line between Washington DC and Los Angeles in color 0.I    The DRAWLINE command cannot be issued from the [P]arameter level.  ItG  operates ONLY when contained in a GEO*.DAT file that is processed forG  the map, or in a text file that is appended to a map with the INCLUDE
  command.!VECTOR (or V)     Continue a lineG  VECTOR latx longx   draws a line starting at the position of the lastF  DRAWLINE or VECTOR, to (latx,longx) using the color specified in theH  last DRAWLINE.  For example, if the following lines immediately follow#  the line in the DRAWLINE example:  VECTOR  41.83   -87.75  VECTOR  38.67   -90.25H  a line from Los Angeles to Chicago to St, Louis will be drawn in colorH  0.  The VECTOR command may be abbreviated by V (i.e., V 41.83 -87.75).$DRAWCIRCLE        Draw circle on mapJ  DRAWCIRCLE latcenter longcenter latrad longrad color    draws an ellipseH  centered at (latcenter,longcenter) and with latitude (vertical) radiusG  latrad and with longitude (horizontal) radius longrad, and with colorI  color. The command operates ONLY when contained in a GEOn.DAT file thatH  is processed for the map. Color is the color in which the line will beG  drawn. If omitted, color defaults to 5, which is displayed as yellow.
  Example:"  DRAWCIRCLE  38.9  -77.0  10 20 6E  draws an oval centered on Washington DC that is 10 degrees from theI  center to the northernmost point, and 20 degrees from the center to the$  easternmost point, and in color 6.ⁿ"SUNLIGHT     Terminator definitionJ  SUNLIGHT angle   specifies the sun's elevation angle for the terminator.C  The default is -0.8333, which corresponds to apparent sunrise andI  sunset, when the edge of the sun is just visible.  0 corresponds to theF  geometric terminator, which divides the earth into two equal halves.+TWILIGHT     Twilight terminator definitionG  TWILIGHT angle   specifies the sun's elevation angle for the twilightJ  terminator.  The default is 0.  -6.00 corresponds to civil twilight, -12G  corresponds to nautical twilight, and -18 corresponds to astronomicalC  twilight.  If this angle is greater than or equal to the SUNLIGHT0  parameter, the twilight area is not displayed."TLMASK       Twilight area patternI  TLMASK n   specifies the fraction (in 16ths) of halftoning for twilightI  display.  8 is the default, which gives 1/2 light and 1/2 dark for the G  twilight area.  You may have to experiment with this value to get theH  best display for your monitor.  A value of 4 may give a better effect,H  particularly if you wish to emphasize the terminator relatively to the  twilight line.$SUNANGLE     Sun rise/set definitionF  SUNANGLE angle   sets the elevation angle of the sun used to computeG  sunrise and set.  The default is -0.8333 degree, which corresponds toI  the sun just breaking the horizon, considering refraction effects. This=  parameter does not affect the terminator line calculations..NORMAL       Normal Display (GEOCLOCK default)J  This highlights the sunlit area and displays the sun symbol at the sun's  subpoint.1REVERSE      Reverse Display (for LCD monochrome)H  This highlights the non-sunlit area and displays the sun symbol at the=  sun's subpoint.  This is appropriate for some LCD displays.&LIGHT        All sunlight is displayedJ  This highlights the entire screen, and does not display the sun symbol. H  This often provides a better display of details of small-area maps, on?  which terminator display may be unimportant, e.g., city maps.%DARK         No sunlight is displayedI  This does not highlight any of the screen, and does not display the sun	  symbol.%BLANK        Highlighting is not usedG  This does not perform any highlighting.  This is appropriate for some0  specialized maps which use more than 7 colors.ⁿHThese commands are special - they are activated by pressing a letter keywhile a map is displayed.T            Set new timeC  Pressing the T key prompts you for a new display time in yy/mm/ddG  hh:mm:ss format.  This does not change your PC's clock.  All times inI  GEOCLOCK use the 24 hour format.  The EGA/VGA/SVGA version shows a pop-G  up window with this command.  You can use the cursor keys to edit theH  time, use ENTER to accept the new time, or ESC to reject the new time.D    In the monochrome version, type in the data in yy/mm/dd hh:mm:ssH  format.  Any missing data will revert to the current local time.  ThusJ  "///12:0:0" sets the time to today at 12 noon, while 91 01 01 0 0 0 sets(  the time to midnight, January 1, 1991.F            Change time rateC  Pressing the F key prompts you for the rate of change of time perD  display update.  The prompt asks for the number of hours (possiblyJ  fractional or negative) for the displayed clock to be incremented duringG  each cycle, e.g., 0.25 for 15 minutes every 1 to 20 second cycle. TheG  hour:minutes:seconds format can be used if desired, e.g., 0:15 for 15%  minutes, or 0:0:5 for five seconds.+U            Change display update intervalB  Pressing the U key prompts you for the screen update interval inH  seconds. When this value is entered, the display is immediately drawn.C  Subsequently, the screen in updated at the specified interval andH  synchronized with the clock. Thus, if 15 is specified, the screen willB  be updated at 0, 15, 30, and 45 seconds past the minute. If yourD  computer is not fast enough to achieve the specified interval, theF  smallest integer multiple of this interval which works will be used.R            Reset timeJ  Pressing this key restores the display time to the current time, and the:  display update rate to real time.  R undoes F, T, and U.╝FThe first four commands are special - they are activated by pressing a*letter key while a map is being displayed.P            Enter a commandH  Pressing this letter key brings up a box for entering a command.  TypeF  the command and any parameters, followed by ENTER.  The command will  take effect immediately.-L            Return to previous map displayedI  Pressing the L key returns the display to the previous (Last) map whichE  was displayed.  This is useful if you want to switch back and forth  between two maps.D            Measure distanceI  Pressing the key starts the distance measuring function.  This functionH  is available only to registered users.  See "Distance Measurement" for  more information.Z            Select another mapJ  Pressing the key starts the "Zoom" function.  This function is availableJ  only to registered users.  It is not a true zoom, but selects maps whichG  contain the point under the cursor.  See "Zoom" for more information.9FAST         Use reduced accuracy but faster calculationsJ  Forces GEOCLOCK to use a faster but slightly less accurate algorithm forE  drawing the sunlit area. This is the default for systems without an  80x87.6SLOW         Use high accuracy but slower calculationsD  Forces GEOCLOCK to use the high accuracy algorithm for drawing theI  sunlit area.  This is the default for systems with an 80x87. On systemsH  with an 80x87, the difference in speed between SLOW and FAST is negli-G  gible, while on those systems without an 80x87, FAST is approximatelyH  twice the speed of SLOW.  These options do not effect polar projection!  or azimuthal-equidistance maps.0387          Activate speedup with 80387 or i486H  This command activates the use of special 387/486 commands which speedJ  up calculations, especially on polar and azimuthal-equidistance maps. IfC  you do not have a 387 type coprocessor, the results of using this?  command are unpredictable. It MAY work on IIT and CYRIX 287s.?The following three commands control the optional HAM features."HAMDB        Specify HAM data baseJ  HAMDB file   loads the HAM call sign data base from file the named file.F  Only the first occurrence of this command in a GEOCLOCK execution isI  effective (i.e., the data base will not be reloaded or changed). A goodJ  place for this command is in the GEOn.DAT file corresponding to your HAMJ  map. The HAM data base and other required files are an extra cost option  in GEOCLOCK."HAM          Activate HAM featuresI  This command activates the HAM features on azimuthal-equidistance maps.H  A good place for this command is in the GEOn.DAT file corresponding to  your HAM map.$NOHAM        Deactivate HAM featuresHThe following two commands may be needed to control screen flickering orDflashing on some graphics boards that do not follow the IBM standardexactly.6NOBLINK      Required for some Trident graphics boardsH  This command prevents the markers from blinking on the Distance screenH  on some graphics adapters. You may want to use the MCOLOR command with(  NOBLINK to improve marker readability.6FLICKER      Required for some Trident graphics boardsI  This command forces GEOCLOCK to bypass the video BIOS and issue changesE  to the video memory start address and palette directly to the videoF  hardware. This is necessary to prevent flickering or blinking of the$  display on some graphics adapters.6QUIET        Do not beep on cycle completion (default)%SOUND        Beep on cycle completion⌠H    The EGA graphics adapter provides for the simultaneous display of 16Hcolors from a palette of 64.  The 16 colors that can be displayed simul-Gtaneously are used to represent 16 features displayed by GEOCLOCK.  See."Colors and Default Colors" (4.2) for details.I    The following three commands are used to control the colors displayed$on the screen for these 16 features.CSET         Color change menuF  This command is activated by pressing P (to get the command prompt),I  followed by CSET.  A menu is displayed with the 16 color feature names,F  numbers, and color values.  The color values are expressed by combi-#  nations of the following letters:1       B  = bright blue              b = dim blue2       G  = bright green             g = dim green0       R  = bright red               r = dim redI  For example, white is rgbRGB (r + R = full red, full green, full blue),J  bright yellow is rgbRG (full red, full green, dim blue), and grey is rgbI  (dim red, dim green, dim blue).  To change to color of a feature, enterG  the feature number, followed by a space and the color value.  For ex-E  ample, to change the color of non-sunlit land (feature 2) to brown,  enter:  2 gRG  and to change the color of sun-lit land (feature 10) to bright yellow  enter:
  10 rgbRGD  You can experiment with different color values to produce the mostH  pleasing effect.  CSET shows changes in the color palette as you enter  them.COLOR        Set colorI  The COLOR command provides a way to change the GEOCLOCK default colors.  The format is:  COLORnddbbI  where n is the feature number (0-7), dd is the color value for the non-I  sunlit feature, and bb is the color value for the sunlit feature (n+8).G  The easiest way to get the proper values is to use the CSET menu. TheE  proper COLOR commands to produce the colors as modified by CSET areE  given on the right hand side of the CSET menu. For example, for theD  color values given in the CSET example, the command is COLOR22062.+MCOLOR       Set color for Distance cursorsJ  This command sets the colors of the Markers on the "D"istance screen. ItI  may be required to improve the appearance of the cursors if the NOBLINKG  command was used.  The syntax is MCOLORxxyy. Marker 1 is set to colorJ  value xx, and Marker 2 is set to color value yy. For example, MCOLOR5961H  sets Marker 1 to 59 (bright cyan) and Marker 2 to 61 (bright magenta).!JThe commands below specify the capabilities of your color graphics system.9See also "Configuring for EGA/VGA/SVGA Graphics Systems."(EGA          Specify EGA graphics systemI  This command should be included in the GECONFIG.DAT file if you have anJ  EGA system. The command prevents VGA and SVGA maps from being displayed.(VGA          Specify VGA graphics systemH  This command specifies that you have a VGA system. This is the defaultE  for GEOCLOCK, so the command is usually not required. If you have aD  super EGA (one that supports 640x480) rather than a true VGA, thisJ  command may be required. The format of the command is VGAa/b/c/d , whereA  a, b, c, and d are the decimal values of the AX, BX, CX, and DXF  registers to enter the 640x480x16 graphics mode by executing INT 10.=SVGA         Specify 800x600 super VGA (SVGA) graphics systemD  This command specifies that you have an 800x600x16 color Super VGAH  (SVGA) display. The format of the command is SVGAa/b/c/d , where a, b,G  c, and d are the decimal vales of the AX, BX, CX, and DX registers toJ  enter the 800x600x16 graphics mode by executing INT 10. "Configuring forJ  EGA/VGA/SVGA Graphics Systems" has parameter values for a number of SVGA  manufacturers.7SHOWVGA      Convert EGA maps to VGA format for displayJ  This command forces all EGA maps to be displayed in VGA format. GEOCLOCKJ  converts the maps on the fly by duplicating some horizontal lines. UsingJ  this command allows the higher resolution VGA characters and lines to beH  displayed on EGA maps, and prevents your graphics system from changingJ  video modes when switching between EGA and VGA maps. It does NOT enhance  the resolution of EGA maps.ASHOWSVGA     Convert EGA and SVGA maps to SVGA format for displayJ  This command forces all EGA and VGA maps to be displayed in SVGA format.J  GEOCLOCK converts the maps on the fly by duplicating some horizontal andF  vertical lines. Using this command allows the higher resolution SVGAH  characters and lines to be displayed on EGA and VGA maps, and preventsG  your graphics system from changing video modes when switching betweenJ  EGA, VGA, and SVGA maps. It does NOT enhance the resolution of EGA maps.÷H    This function allows the user to change the map background using theHcursor.  A mouse or the arrow keys can be used.  To invoke the function,Epress the letter Z.  The screen will be stabilize without any time orGsunlight information, and an Iron-Cross type cursor will appear.  AmongEother things, the Zoom function can be used to identify all maps thatinclude a given location.I    Use the mouse and/or arrow keys to locate a position on the map.  (IfGyou hold the shift key down with the arrow keys, the cursor will move 8Gtimes faster than non-shifted arrows.)  Each press of the right or leftGbutton on the mouse, or CONTROL or ALTERNATE keys on the keyboard, will*switch to a new map containing that point.I    The left mouse button or CTRL selects the next smaller map containingEthe point under the cursor (zooms in).  The right mouse button or ALTHselects the next larger map containing the point under the cursor (zoomsHout).  The cursor will remain at the specified latitude/longitude duringJthe switch.  When the desired map is displayed, press the middle button or)the ESCAPE key to return to time display.╨I    This function provides a display of the coordinates of three selectedGpoints, and the distances between them, as controlled by a mouse or theHkeyboard.  The function is invoked by pressing the letter D.  City namesJremain on the map, and two text lines appear at the bottom of the screen. KThey indicate latitude and longitude of three points, and distances betweenthem.K    Point 3 is the current cursor position, which you can change with mouseImotion or the arrow keys.  (If you hold the shift key down with the arrowGkeys, the cursor will move 8 times faster.)  Point 1 is selected by theJleft mouse button or the CONTROL key on the keyboard.  Point 2 is selected/by the right mouse button or the ALTERNATE key.K   To maintain smooth cursor movement, the distance and coordinate displaysHare updated only when the cursor is not moving.  By default, the displayBshows distance (in km and miles) on the top line, and location (inEdegrees/minutes/seconds) on the bottom.  By pressing "A", azimuth (inEdegrees, first from A to B, then B to A) and distance (in km) will beDdisplayed.  "D" returns to distance only.  Pressing "." will displayKlocations in degrees and fractions, while "'" will return to DMS format.   K To return to the normal GEOCLOCK display, press ESCAPE or the center mousebutton. [G     For registered users only, additional control over city placement,Ccolor, size, and local time display is possible.  All are marked byEcharacters appearing after an exclamation point (!) on a city line inHGEOn.DAT.  This new data consists of an optional string of characters asfollows:"     A - show city name Above mark"     B - show city name Below mark$     L - show city name Left of mark%     R - show city name Right of mark6     Y - show city name in color 5 (Yellow by default)5     E - show city name in 8x14 font (8x8 by default)Cnumber - show city name in color number (e.g., 6 shows city name inC         color 6).  Color numbers are described in "Color Control."H     N - show a name without a mark.  This is particularly useful if you8         want to name an area, such as the Pacific OceanJ     After these optional codes, the line may be followed by a space and aItime zone code.  If included, this specifies that the local time for thatCcity is to be displayed to the right of the city name.  If a "*" isHincluded, the name of the time zone will be displayed in addition to theAtime.  THE SPACING OF THESE CHARACTERS IS CRITICAL.  For example:                  ET    38.90   -77.02  Washington !E   42.65   -73.75  Albany !Y$   35.08  -106.65  Albuquerque ! *MT   42.28   -83.75  Ann Arbor !A   33.75   -84.39  Atlanta !0   44.30   -69.76  Augusta"   33.52   -86.81  Birmingham ! CT#   46.80  -100.78  Bismarck !B6 *CTK     In this example, Washington will be displayed in the 8x14 font, AlbanyKwill be displayed in yellow, Albuquerque will be followed by the local timeFand MST or MDT as appropriate, Ann Arbor will appear above the marker,IAtlanta will be displayed in color 0 (red), Birmingham will appear followFby local (central) time but without a CST or CDT, and Bismarck will beHdisplayed below the marker in color 6 (black) and followed by local timeand CST or CDT.  H    The EGA graphics adapter provides for the simultaneous display of 16Gcolors from a palette of 64.  The VGA graphics adapter provides for theJsimultaneous display of 16 colors from a palette of 262144.  Most programsIuse the default palette, which roughly corresponds to the colors providedGby the CGA in text mode.  In order to make the map display the most at-Itractive, the EGA/VGA/SVGA version of GEOCLOCK does not use this standardIpalette.  Instead, the 16 colors that can be displayed simultaneously areDused to represent 16 features displayed by GEOCLOCK. The first eightFnumbers are for features not in sunlight, and the second eight are forfeatures that are in sunlight:F    The 16 color values are expressed by combinations of the followingletters:1       B  = bright blue              b = dim blue2       G  = bright green             g = dim green0       R  = bright red               r = dim redF  For example, white is rgbRGB (r+R=full red, g+G=full green, b+B=fullD  blue), bright yellow is rgbRG (r+R=full red, g+G=full green, b=dimJ  blue), and grey is rgb (dim red, dim green, dim blue).  These colors areA  also indicated with numerical values determined by the formula:1   Color value = 32*r + 16*g + 8*b + 4*R + 2*G +B*Default colors in GEOCLOCK are as follows:DFeature      Use                  Color         rgbRGB   Color Value=  0    Political Bdy (dark)       red           ---R--      4=  1    Water (dark)               blue          -----B      1=  2    Land (dark)                dark green    -g----     16=  3    Land/Water Bdy (dark)      green         ----G-      2=  4    Text Background (dark)     black         ------      0=  5    Aux Text Color (dark)      yellow        rgbRG-     62=  6    Lat/Long Lines (dark)      black         ------      0=  7    Frame and Text             white         rgbRGB     63=  8    Political Bdy (light)      bright red    rgbR--     60=  9    Water (light)              light blue    --b--B      9= 10    Land (light)               green         ----G-      2= 11    Land/Water Bdy (light)     light green   -g---G-    18= 12    Text Background (light)    black         ------      0= 13    Aux Text and Sun (light)   yellow        rgbRG-     62= 14    Lat/Long Lines (light)     black         ------      0= 15    Frame and Text             white         rgbRGB     63J    The "rgbRGB" designators are used for changing display colors with theHCSET function.  The color values are used with the COLORnddbb command at(the [P]arameter line or in GECONFIG.DAT.K    In order to avoid an annoying "blinking" effect on every screen update,Kit is desirable that there be identical colors for colors 4 and 12, and forcolors 7 and 15.G    There are at least four ways to change default values in GEOCLOCK. DMost default values can be overridden for all operation by insertingIanother command in the GECONFIG.DAT file.  This can be done with any textHeditor.  For example, MARK, CITY, and LINEnn commands are often added toJthe GECONFIG.DAT file.  Some users also add their favorite map at the end,Jso it (rather than Map 1) comes up automatically for display on initiatingthe program.J    The second way to change default values is by adding commands as para-Kmeters when executing GEOCLOCK (usually by typing GEOCLK at the DOS command@line).  The third way is through the normal [P]arameter process.H    The fourth is by adding commands in map data files (GEO*.DAT).  WithGthis method, you should be aware of which commands will apply only to aGgiven map, and which ones will change all map displays until a contrarycommand is issued.K    Some commands in GEOCLOCK are "global," while others are "non-global." DGlobal commands remain in effect until they are countermanded with aIcontrary command, or the program is terminated.  Non-global commands loseEtheir effect once the user changes maps.  Most commands regarding mapGdisplay, map annotation, time control, the terminator, and twilight areJglobal.  INCLUDE, DRAWLINE, and daylight/darkness commands (NORMAL, LIGHT,etc.) are non-global.  ≥H   Time zones are not built into the GEOCLOCK program.  Rather, they areHdefined in the GECONFIG.DAT file.  These definitions are for the current6year, and are usually updated at least twice a year.  H   Time can be specified for individual locations by entries in GEO*.DAT7files.  (See "City Name Placement and Time Display.")  J   In the abstract, time is an immutable commodity.  However, its measure-Kment and legal specification are constantly changing.  Time zones, daylightKsaving time, and even the calendar itself have changed from year to year orGcentury to century.  Some important factors in the measurement of legal:time (which is what GEOCLOCK shows) are discussed below.  J   Great Britain adopted Greenwich Mean Time as the first standard time byHact of Parliament in 1880.  The four standard time zones were adopted inGthe U.S. in 1883.  The Meridian Conference, held in Washington in 1884,Iestablished the Greenwich (near London) as the reference point for world-Hwide longitude measurements, and for the general scheme of time zones.  F    Some countries have switched from one time zones to another by lawH(e.g., France).  Also, time zone boundaries have been moved within coun-Ctries (e.g., , and portions of some countries have been assigned toIdifferent time zones (e.g., western Ohio).  Thus, if you specify dates in:past years, times shown GEOCLOCK are not always correct.  G    GEOCLOCK will display "standard" times for dates prior to 1884, ButGthey obviously do not correspond to actual time measurements which were9used then.  These were usually based on local sun time.  J    Daylight saving time is a special case.  Much of the U.S. has observedJDST since World War II, and a uniform set of dates was specified in 1967. EThe DST period (now in all states except Arizona, Hawaii, and part ofHIndiana) has been from early April to late October since 1987.  All con-Htinental European countries have observed summer time from late March toDlate September since 1980 or 1981, and some have done so for severalGdecades.  Great Britain and Ireland have summer time from late March tolate October.  I    The DST command allows daylight saving time to be used under the cur-Grent set of specifications for a period of years selected by the user. I(See "Time Control and Display.")  The default period is back to 1980 andEindefinitely into the future.  However, there does not seem to be anyHpractical way of selectively recognizing individual countries' differentJsummer time patterns in the past, or in the future.  For example, GEOCLOCKI(with GECONFIG.DAT set for current time patterns) will not correctly showEtimes in 1979, when France observed summer time but Germany did not. I    There are strong signs that the USSR has shifted its entire time zoneLstructure (11 zones) to be earlier by one hour in most (but not all) areas. HThere are some indications that the Moslem republics in the south of theIUSSR will not observe summer time in the future.  These have not yet beenHincorporated into the current GECONFIG.DAT file for display in GEOCLOCK,.for lack of clear and authentic information.  K    The SHOWDAY function in GEOCLOCK gives days of the week accurately backKto the year 100 AD.  It uses the Julian calendar up to October 4, 1582, and2the Gregorian calendar from October 15, 1582 on.  I    An error of less than one day in 100 years caused the Julian calendarEto diverge from accepted benchmarks.  By the 16th century, the vernal9equinox occurred around March 11, rather than March 21.  D    Pope Gregory XIII promulgated the "new style" calendar in 1582. GThursday, October 4, 1582 was followed by Friday, October 15.  CatholicEcountries adopted the Gregorian calendar immediately, or within a fewKyears.  Most Protestant countries on the Continent adopted the new calendarJaround 1700.  England and the American colonies changed in 1752, by act ofKParliament.  Thus, days of the week shown by GEOCLOCK for events in England<and America between 1582 and 1752 are generally incorrect.  G    Orthodox Christian countries adopted the Gregorian calendar later. HRussia was the last European country to do so, after the communist revo-Hlution of 1917.  As a result, the USSR celebrates the October Revolution>(October 25, 1917 in the "old style" calendar) on November 7. öE     The ephemeris data in GEOCLOCK is calculated using formulas fromG"Astronomical Formulae for Calculators" (Jean Meeus, Willmann-Bell Inc,?Richmond VA).  They were calibrated by comparing with data fromI"Interactive Computer Ephemeris" (ICE) (Nautical Almanac Office, Code FA,FUS Naval Observatory, Washington, DC 20392).  For a period of 400 daysEincluding 1991, the maximum and RMS latitude errors are 0.0047383 andK0.0019377 degrees, while the maximum and RMS longitude errors are 0.0131104Hand 0.0053660 degrees.  This accuracy is approximately four times betterKthan the method used in GEOCLOCK 4.2 and earlier, and should provide better#accuracy for past and future years.I     The terminator is shown as the locations where the sun's center is aIspecified angle above the horizon, ignoring atmospheric effects.  For theEdefault value of 0 degrees, the sunrise occurs earlier and the sunsetKoccurs later than the terminator indicates.  The sun rise and sun set timesIare also computed as the times that the sun's center is a specified angleKabove or below the horizon.  The default value, -0.8333, corresponds to theCnormal definition of sun rise and set (as printed in newspapers andIalmanacs), where the visible top edge of the sun just breaks the horizon.HI     GEOCLOCK is written entirely in Turbo Pascal version 5.0, except forJthe mouse interface routines and a few inline sections required for speed.HIt has approximately 9000 lines of source code. It uses 8 byte reals forEmost calculations, and thus relies on the 80x87 emulation package forKsystems without a math co-processor. The EGA/VGA/SVGA version uses a customIgraphics package which provides access to special hardware features (suchGas independent control of screen planes, disk I/O directly to the videoJmemory, fast fill, and preserving the graphics memory during text display)Gthat are not available in the EGAVGA.BGI driver. The monochrome versionHuses the GRAPH unit, and builds a screen image in RAM before copying theFimage in its entirety to video memory. GRAPH unit functions other thanDPUTIMAGE are not used except for a few special applications, such asCdrawing the graphics cursor, and updating the position and distance"displays in the distance function.$J     The maps used for the GEOCLOCK program were produced by a custom dataEbase and software system. This system consists of a highly compressedGvectorized map data base and a set of programs to convert the data intoGcustom maps. The data base is a PC conversion of World Data Bank II. ItHcontains approximately 5.7 million vectors covering coastlines, islands,Elakes, rivers, and similar geologic features, together with politicalDboundary data. It covers the entire earth, and included features areIaccurate to approximately 600 meters. World Data Bank II was converted toKthis custom PC format by an ad hoc program which took advantage of specificKfeatures of both data bases. In its operational form, the PC data base uses?approximately 0.84 bytes per vector, and in archival form takesEapproximately 0.5 bytes per vector. The data base is therefore easily)stored and manipulated on an AT class PC.H     Custom maps are generated by using two programs. The first, MAPGEN,Hreads the appropriate parts of the map data base and produces separationIfiles of the required feature data as EGA, VGA, or 800x600 raster images.IRectangular, polar, azimuthal-equidistant, and Lambert projections may beJused in forming these separation files. Depending on complexity and scale,Kthis process takes between 30 and 300 seconds on an AT with a co-processor.EThe second, MOVIE, allows the user to process the separation files toJselect the features and colors for the final map, including filling areas.GThis program also writes the map in a rasterized compressed format withIheaders and trailers so that it may be easily used as background data for3other programs (for example, the GEOCLOCK program).J     Both these programs, and the converted data base, are proprietary andHnot yet available to the general public. World Data Bank II is availableFfrom National Technical Information Center, Springfield, VA, for about$1000 on 5 reels of tape.╗G  The GEOCLOCK HAM package activates several new features of particularCinterest to amateur radio operators and short-wave listeners. Theseinclude:*Azimuthal-Equidistant (Great Circle) maps.&Day, night, and twilight zone display:C- Twilight zone parameters can be set to indicate boundaries of sun8  illumination on the F- and D-layers of the ionosphere.HAmateur radio call sign analysis (based on a user-maintainable call signCdata base).  When a call sign (or prefix) is entered, the followinginformation is displayed:- Remote station location"- short and long great circle path'- short and long path azimuth and range%- remote station (reciprocal) azimuth+- UTC, local, and remote station local time&- DXCC and WAE country identifications- CQ and ITU zones%- Continent, area, and location namesH  The package has three major components: a custom Azimuthal-EquidistantJmap centered on your station; a call sign data base, and a utility programDto process the text call sign data base into the GEOCLOCK form. YourJregistered copy of GEOCLOCK will use this data base to overlay HAM data onthe custom map.K   The custom Azi-Equi map centered on your location is named MAP9009.EGA. HA custom GEO9009.DAT file is also provided to control the display of HAMdata.C   These features are provided in addition to the other features of	GEOCLOCK.~G   To start the HAM package, enter "GEOCLK MAP9009" at the DOS prompt. HThe program will start with your custom map and an indication of the sunCand terminator locations.  In the present release, ham features are!activated only on the custom map.G   TIP:  Edit your GECONFIG.DAT file with an ASCII text file editor andJadd the command "MAP 9009" as the last line of this file.  You will now beGable to start the Geoclock program by simply entering GEOCLK at the DOSGprompt.  Geoclock will then start up automatically with your custom map
displayed.H  You should see a color Equi-Azi map displayed on your screen against aIblack background.  Your location at the center of the map is shown with aEcross symbol.  Around the edge of the map are tick marks for every 10Jdegrees of azimuth.  In the bottom right corner, your name, call sign, andKlocation will be displayed.  In the bottom left corner two clock lines willGbe displayed: GMT clock and local time at your location.  The format ofIclock information can be tailored to suit your taste in clock style.  See*the "commands" section of the help system.I  In a few seconds (depending on the speed of your computer), the currentKsunlight, night, and twilight zones will be displayed.  A yellow "sun" willIappear at the current sun subpoint (i.e., the spot on Earth where the sunFis currently directly overhead).  Geoclock will continue to adjust theGdisplay to keep up with real time, at a rate dictated by the processingIpower of your computer.  The date/time of the present display is shown on$the clocks in the lower left corner.I  Note: The rate of updates can be slower (approximately half as fast forIthe worst case) whenever the boundaries of the twilight zone approach theKedges of the Equi-Azi map.  This is because a larger number of calculationsFare required in order to accurately display the twilight zone boundaryHaround the map edge. Geoclock automatically adjusts to this condition in6order to insure that the map display remains accurate.╚J   To activate call sign analysis, simply begin to type in the letters andJnumbers of the amateur radio call sign of interest.  When the first key isKdepressed, a window pops open and the call sign you are typing is displayedKin the window.  Backspace and cursor keys may be used to correct any typingIerrors.  When the call sign has been completely entered, press the RETURNkey.I  To abort call sign entry, press the ESCape key.  To clear the call sign5display, press any letter, then BACKSPACE and RETURN.I  You do not need to enter an entire call sign.  Geoclock will operate onIcall sign prefixes.  However, Geoclock contains over 1,700 entries in itsHcall sign analysis database.  By entering a complete call sign, you will:frequently benefit from more precise location information.F  Call signs containing "/" may be entered directly from the keyboard;0e.g., FR5ZD/E, KN3T/KH6, HB0/DL7FT and SP9PBE/6.D  Once a call sign has been entered, Geoclock displays the followinginformation:I  a.   a cross "mark" at the location of the station is added to the map.HThe location chosen is the most accurate location known to the database.F  b.   the local time at that distance location is added to the bottomKleft corner of the screen.  This is the third clock time, labelled "mark:".HThis time is continually updated, along with all the other clocks on theDscreen.  Rules for local daylight savings (summer) time are applied.B  c.   short and long great circle paths from your location to theJdistance "mark" are displayed on the map.  If you look carefully, you willKsee the long path has a yellow color.  (On an Equi-Az map, the long path isIobvious: it is the path which crosses the edge of the map.)  In addition,Gthe left side of the screen shows the following for both short and longpaths:8  -- azimuth (direction) from your location to the mark.,  -- azimuth from the mark to your location.&  -- distance in miles and kilometers.G  d.   on the left side of the screen, additional information about thecall sign is shown:4  -- DXCC country: standard prefix and country name.3  -- WAE country: standard prefix and country name.@  -- area: state, region, or ooblast within the country for thisKparticular call sign.  For USSR ooblasts, the ooblast number is also shown.J  -- mark: the city or geographical spot which is displayed on the map and+used for distance and bearing calculations.)  -- CQ zone(s) for the area named above.*  -- ITU zone(s) for the area named above.4  To erase the information, press the minus (-) key.ÖC  Most of the Geoclock commands and features described in the otherJsections of HELP are available while using the HAM package. In addition toIreal time operation, Geoclock can be instructed to operate at other datesKand times, and to operate at accelerated rates.  Distances and great circleKdirections can be determined between any locations on the globe.  There are@many commands which allow you to customize the type and style ofDinformation displayed on Geoclock.  You should take time to read the@remaining Geoclock help sections to learn about these additionalDcapabilities.  These will help you get the most out of your Geoclocksystem.K   Geoclock also includes many additional maps of the world, polar regions,Jcontinents, oceans, and individual countries.  These additional maps allowIyou to zoom in on specific areas on interest in the globe; e.g., twilightzone crossings of Africa, etc.I  While using your custom map and ham features, you can enter these otherBGeoclock commands by holding down the SHIFT key while pressing theHappropriate letter.  For example, pressing SHIFT and T (for Time) allowsKyou to change the date/time used to calculate the displayed day, night, andtwilight zones.E  Note:  The SHIFT key must be used.  The CAPS LOCK key and caps-lockJstatus is ignored.  Any keys pressed without the SHIFT will be interpretedas characters for a call sign.D  Geoclock supports two commands which are specific to ham features.JThe HAMDB command specifies the name of the call sign database to be used.JThis command should be in the GECONFIG.DAT file. For example,HAMDB HAM.HDBGspecifies that HAM.HDB contains the call sign data base.  This databaseIMUST be in the format produced by GENHAMDB, not in text format.  Only theFfirst use of HAMDB in a given run has effect - the data base cannot be$changed while GEOCLOCK is executing.D  The second command, HAM, specifies that the HAM features are to beEactivated.  The best place to this command is in the GEO9009.DAT fileGcorresponding to your Azimuthal-Equidistant (Azi-Equi) map.  In the 4.3Hrelease of GEOCLOCK, the HAM features may only be used when the Azi-Equi6map is displayed.  NOHAM deactivates the HAM features.WD  One of the strengths of Geoclock is the ability for you to use theKTWILIGHT and SUNLIGHT commands to determine the boundaries of the day zone,Htwilight zone, and night zone. You can set these boundaries to any valuedesired.I  The value is the offset, in degrees, of the zone boundary from the edgeJof the (geometric) sunlight part of the earth.  Typical values of interest for shortwave operating include:ESUNLIGHT  -6.596     Boundary where sun starts/stops illuminating theD                     D-layer.  This controls absorption on the lower5                     frequency shortwave radio bands.ETWILIGHT  -14.165    Boundary where sun starts/stops illuminating theF                     F-layer. These values are based on average D- andG                     F-layer heights.  They define the Ionospheric GrayH                     Line: a twilight zone where shortwave radio signalsF                     can pass through the D-layer without absorption. K                     Within this zone signals will encounter an illuminatedE                     F- layer whose ionization level will be normally@                     enhanced over that found in the night zone./Other common values for these commands include:ISUNLIGHT  -0.833     Sunset/sunrise at sea level, taking into account theH                     bending of light through the Earth's atmosphere and3                     the apparent width of the sun.KTWILIGHT  -6         Boundary of civil (legal) twilight, where it is bright-                     enough to work outdoors.FTWILIGHT  -12        Boundary of nautical twilight, where it is brightJ                     enough to see the horizon.  One can take navigational;                     sightings with a sextant in this zone.ITWILIGHT  -18        Boundary of astronomical twilight, where sunlight onD                     the upper atmosphere interferes with the use of/                     telescopes by astronomers.I  To use the same values for twilight definition on all maps, enter theseIcommands in the GECONFIG.DAT file.  To specify values for each particularJmap, the commands should appear in the GEO*.DAT file (where "*" represents?the map number; e.g., GEO9009.DAT for your custom Equi-Az map).µI  Analysis of amateur radio call signs is driven by information contained;in the ham database.  The database consists of three files:E  -- HAM42B.DAT:  An ASCII text file containing information describedKbelow.  The "42B" in the name indicates the version number of the database:J"42" indicates that this database was prepared to support Geoclock versionJ4.2, and "B" indicates this is the second release of the database for thisFGeoclock version.  You may have received a more recent version number.G  -- GENHAMDB.EXE:  An executable utility which converts the ASCII textKfile into a binary format used by Geoclock for call sign analysis. Database-validation is also performed by this utility.E  -- HAM.HDB:  The binary format produced by the GENHAMDB.EXE utilityprogram.               HAM42B.DATH   The text form of the call sign data base consists of lines specifyingJkey data about a group of call signs. Each line consists of 11 data items:C1. CallPattern - the leading characters of the call sign group. ForFexample, PY signifies all call signs beginning with the characters PY.K  Wildcard characters are used in describing call sign patterns as follows:9  # -- represents any single digit; i.e., 0, 1, 2, ... 9.E  @ -- represents any single alphabetic character; i.e., A, B, ... Z.E  ? -- represents any single character, either alphabetic or numeric.+  * -- represents any string of characters.I  For example, PY#Z* represents any call sign beginning with PY, followedKby any single digit, then the letter Z, and then anything else. PY0ZZ wouldmatch this pattern.K  All characters are interpreted as upper case.  This file has been createdIin lower case.  If you add entries of your own, you may wish to make themIupper case so that you can easily recognize your own additions for future#maintenance and debugging purposes.I2. HamLat - the latitude of the location corresponding to this call sign.HThis may be in decimal degrees (-15.146 for 15.146 degrees South), or inIdegrees/minutes/seconds ("15 8 45.6S"). If the latter format is used, the)latitude must be enclosed in quote marks.K3. HamLong - the longitude of the location corresponding to this call sign.GThis may be in decimal degrees (-15.146 for 15.146 degrees West), or inIdegrees/minutes/seconds ("15 8 45.6W"). If the latter format is used, the)latitude must be enclosed in quote marks.E4. HamTimeZone - the time zone code for local time for this call signCgroup.  For example, ET stands for US Eastern time.   The time zone.acronyms are defined in the GECONFIG.DAT file.D5. HamCQzone - the CQ zone for this call sign group. If the zone has>imbedded spaces, it must be enclosed in quotes; e.g., "3 4 5".F6. HamITUzone - the ITU zone for this call sign group. If the zone has/imbedded spaces, it must be enclosed in quotes.I7. HamContinent - the continent for this call sign group. NA, SA, AF, EU,,AS, AN, and OC may be used as abbreviations.G8. DXCCprefix - the standard DXCC call sign prefix designation for thisECallPattern.  The DXCC country identification for this CallPattern isdetermined by this prefix.G9. AreaName - the name of the area within a country which is covered byBthis CallPattern; e.g., state, ooblast, region, or other political.subdivision.  This must be enclosed by quotes.I10. MarkName - the name of the specific place used to represent this call>sign group. Ordinarily this should correspond to the latitude,Glongitude,and time zone specified above. If the MarkName is missing,the3Areaname is used.  This must be enclosed by quotes.F11. WAEprefix - the standard WAE call sign prefix designation for thisDCallPattern.  The WAE country identification for this CallPattern isJdetermined by this prefix.  If omitted, it is assumed that the WAE country is the same as the DXCC country.INOTE -- Items enclosed in quotes must be separated from one another by at?least one space.  All items must be contained on a single line.A   Another type of line in the text call sign data base specifiesIequivalences in call signs. For example, ZY* =PY* specifies that any callHsign starting with ZY should be treated as if it started with PY; i.e., 0ZY5EG can be processed as if the call was PY5EG.K  Through appropriate combinations of "equates" and wildcards, the databaseKand analysis algorithm is capable of accurately determining the location of;any call sign heard on the air, including special prefixes.E  Mobile call signs (K3NA/MM, for instance) will be processed but notHresult in a location display on the map, since the exact location of the&station is not predictable in advance.K  You may add additional entries to the HAM42B.DAT (or later versions) fileJwith a simple ASCII file editor, following the conventions outlined above.K  Any line beginning with a space in column 1 is interpreted as a comment. FYou can see a typical comment line in the first line of the HAM42B.DAT3file, where columns are named for your convenience.          GENHAMDBJ  After the HAM42B.DAT file has been modified, it must be converted into aCformat which can be processed by the Geoclock program.  The programJGENHAMDB.EXE does this conversion.  To start the program, enter at the DOS;prompt:  GENHAMDB (filename).  Example: GENHAMDB HAM42B.DATK  Conversion processing can take several minutes, depending on the speed ofJyour computer.  The GENHAMDB utility provides you with a cryptic status of,the current state of the conversion process.G  When conversion is completed, GENHAMDB prompts you for a name for theJconverted file.  The normal convention is to use the name HAM.HDB.  If you4do not specify a name, GENHAMDB will assume HAM.HDB.KNOTE -- Geoclock is initially configured to look for the database under theKname HAM.HDB.  To change this, you must modify the GEO9009.DAT file with anIASCII file editor.  The command line HAMDB specifies the name of the .HDBGfile to use when your custom map is displayed.  For simplicity, you may;wish to always tell GENHAMDB to name its output as HAM.HDB.F  After writing the .HDB file to disk, GENHAMDB allows you to test theIdatabase without running Geoclock.  You will be prompted for a call sign.HGENHAMDB takes the call sign given and looks it up in the data base, andJdisplays the data base entry, including a summary of the equivalences usedDin the analysis.  You can test as many call signs as you wish beforeexiting the program.G  Note -- You will also see other numbers displayed along with the dataBbase entry.  These other numbers are used by the Geoclock software$developers in order to debug errors.I  To exit GENHAMDB, enter an empty call sign (i.e., just press the RETURNkey).K  If you wish to conduct further tests on the HAM.HDB file, simple re-enter;GENHAMDB by typing the following command at the DOS prompt:     GENHAMDB HAM.HDB /DJwhere "HAM.HDB" is the name of the .HDB binary file to be tested. GENHAMDBKtakes note of the "/D" debug switch on the command line, skips the database=construction phase, and prompts you to enter test call signs.H   The call sign data base included with the HAM version of GEOCLOCK wasCdeveloped by Eric Scace, K3NA.  This is also a copyrighted softwareHproduct.  You may use the database for any other software which you haveDdeveloped for your personal use (e.g., contesting software, QSL cardIprocessing programs, etc).  However, the database can not be incorporatedKinto any software product which is sold or distributed as shareware withoutprior permission.K   Questions, comments, additional data and corrections to the ham databaseKare welcomed!  These can be sent to Eric via the Geoclock RBBS, or by other	means to:  Eric L. Scace  K3NA  10701 Five Forks Road  Frederick MD  21701  home:  +1-301-293-2448  work:  +1-703-689-6556  fax:   +1-703-689-5036  telex: +23-740-0368  ERIC UC/  X400 e-mail:  C:USA  A:Telemail  O:Sprintmail    FN: Eric  SN: Scace  MI: L.   amateur radio BBS:  K3NA @K3NA└Matching Algorithm (ALG-2):#1.   Use ALG-1 on the input string.12.   If input string does not contain a "/", done(3.   If there was no match, go to step 7,4.   If the match after the / is exact, done-5.   If the end string is /A, /M, or /P, doneI6.   If the end string is a single numeric, replace the first non-leadingDnumeric in the string before the /. If ALG-1 produces a match, done.H7.   If the string exactly matches one of the */ entries, use that entryL8.   Use the shorter of the strings before and after the / (after if equal)     and apply ALG-1ALG-1:?1.   Find the most stringent straight match on the input string;2.   Find the most stringent equate match. If none, go to 4G3.   Make the substitutions, and find the most stringent straight match0(Can be done recursively up to a maximum limit.)&4.   If only one match was found, doneG5.   If both a straight and substitution match were found, use the more
stringent.nJ     If you have registered an older version of GEOCLOCK, you can registerBa new version without cost.  Just un-ZIP the files from the newestGshareware version of GEOCLOCK and run the REGISTER.EXE program that wasKincluded on your original distribution disks.  The latest version is alwaysAavailable from the GEOCLOCK computer bulletin board system (BBS).?F     GEOCLOCK includes a large number of maps.  The following maps areincluded with registration:/    Title               N-S Dist         Center3World                   20016 km     0.00N    0.00E348 States                4163 km    36.00N   95.00W3World VGA               20016 km     0.00N    0.00E348 States VGA            4163 km    36.00N   95.00W3World SVGA              20016 km     0.00N  150.00E348 states SVGA           4163 km    36.00N   95.00W3Eastern US               1441 km    40.00N   80.00W3SouthWestern US          1601 km    37.00N  115.00W3Western Europe           4003 km    47.00N   15.00E3Alaska                   1922 km    63.00N  153.00W3New York City (160)       256 km    40.75N   74.00W3New York City (80)        129 km    40.75N   74.00W3SouthEastern US          1441 km    30.00N   85.00W3NorthWestern US          1121 km    45.00N  118.00W3Chicago                   801 km    41.87N   87.63W3Texas                    1281 km    31.00N   99.00W3Washington DC             320 km    38.90N   77.02W3Carolinas                 641 km    35.00N   80.00W3Pennsylvania              480 km    41.00N   77.00W3New England               480 km    43.00N   73.00W3Central America          4003 km    20.00N   85.00W3South America            8006 km    20.00S   60.00W3Africa                   8327 km     1.00N   20.00E3Australia                4003 km    27.00S  134.00E3India                    3523 km    21.00N   76.00E3Middle East              2402 km    30.00N   40.00E3Micronesia               4003 km     6.00N  130.00E3Japan                    2242 km    38.00N  135.00E3China                    4484 km    37.00N  107.00E3North Polar Map         10008 km    90.00N    0.00E3North Polar Map          5004 km    90.00N    0.00E3South Polar Map         10008 km    90.00S    0.00E&The supplemental map package includes:3Western Europe           1810 km    48.10N    5.50E3North Central Europe     1081 km    50.30N    7.50E3San Francisco Area        240 km    37.78N  122.42W3USSR                     6405 km    55.00N   85.00E3North Atlantic           3203 km    54.00N   20.00W3Scandinavia              2082 km    63.00N   18.00E3Highlands and Islands     480 km    57.00N    4.00W3Southern California       240 km    33.40N  118.25W3Southern California       480 km    34.30N  117.30W3Sierra Nevada             400 km    38.25N  121.00W3South Australia          1681 km    32.50S  135.00E3West Australia           2562 km    24.00S  122.50E3New Zealand              1601 km    41.00S  172.00E3Canada                   4003 km    59.00N   97.00W3The Aegean Sea            801 km    38.00N   24.00E3Silicon Valley            120 km    37.40N  122.00W3British Isles            1121 km    54.50N    3.00W3Switzerland               289 km    46.85N    8.25E3Hawaiian Islands          480 km    20.80N  157.60W3Prince William Sound      200 km    60.50N  147.15W3Island of Hawaii          200 km    19.60N  155.43W3Mexico                   2402 km    24.80N  102.50W3Queensland & N.Terr.     2402 km    20.00S  143.15E3SE Australia             1890 km    35.50S  147.50E3World                   20016 km     0.00N  150.00E3Iraq & Saudi Arabia      1601 km    31.50N   41.35E3Kuwait                    480 km    28.40N   47.50EEThe maps distributed are changed from time to time to reflect new in-Kterests.  The GEOCLOCK Bulletin Board always has all the maps available forregistered users.äJ    A free computer Bulletin Board System (BBS) provides support for usersKof GEOCLOCK.  It always has the latest version of the program available forIdownloading.  In addition, it provides a forum for all interested partiesIto exchange programs and information concerning GEOCLOCK and high qualitymapping for the IBM PC.K    Everyone is welcome to use this BBS, but registered GEOCLOCK users haveJaccess to certain special files and have higher access limits. HAM packageJowners also have access to the latest version of the HAM data base. PleaseGhave your registration number handy when you log on for the first time.GExcept for these special files, the messages and files on the board areAavailable to everyone. Your comments and suggestions are welcome.H    You need a modem (1200 or 2400 baud) and terminal emulation softwareF(such as Procomm or Crosstalk) for your PC to access the BBS.  The BBSCnumber is 703-241-7980.  This is a Washington DC metro area number.JGEOCLOCK is also available from many Shareware catalogs, computer bulletin)boards, and CompuServe (CSID 70461,2340).ΘFLicense for multiple users at a single site (for LAN use, estimate the!number of LAN users of GEOCLOCK):Number    Price1         $ 30/User2-9       $ 25/User10-20     $ 20/User21-40     $ 15/Userunlimited $ 600 totalSupplemental Maps: $ 20HAM radio support package: $ 30KCustom maps - $30 for rectangular projection maps covering at least 120,000Hsquare miles (at least 300 miles North to South).  Other projections andsizes by negotiation.HCustom modifications to GEOCLOCK - by negotiation.  Custom modifications?can generally be made on a fixed price basis after agreement tospecifications.IThe supplemental maps and HAM package can be used by each registered userwithout additional charge.ALicenses for multiple sites in an organization can be negotiated.KIn all cases, the purchaser must make all required copies from the suppliedEmaster copy, and must protect the software the same way the purchaserGprotects its own proprietary software to ensure that the license is not	violated.JTerms: Payment must be by VISA, MasterCard, or check in advance.  Purchase?Orders are accepted only for unlimited site licenses and customprogramming.  No CODs.8I    Registration of GEOCLOCK includes a copy of the latest version of theJprogram, a large set of maps (see "Available Maps"), a file with the namesGand locations of many world cities for customizing the maps, a "starterKset" of map overlay files, and an installation program for automatic set-upKon a hard disk. Updates to the program are available to registered users at no charge from the GEOCLOCK BBS.J    The supplemental map set, and the HAM package, can be ordered with theJinitial registration or later. Custom maps and quantity license agreements!are available. Write for details.K    Orders paid by cash or check are accepted by mail.  VISA and MasterCardBorders may be made by mail or electronically via the GEOCLOCK BBS.H    Purchase orders, and checks drawn on or payable to banks outside theJUSA, are not accepted. International postal money orders mailed separately/have not proved reliable and should be avoided.;$30  GEOCLOCK registration, program and maps on 5.25" disks$5   Extra for 3.5" disks2$5   Extra for international air mail and handling$20  Supplemental map setJ$30  HAM package (include your call sign and QTH) (requires EGA or better)8GEOCLOCK   2218 N Tuckahoe St, Arlington, VA  22205-1946▒
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