10 '*************************************************************************
20 '* Filename:          MENU.BAS                                           *
30 '*                                                                       *
40 '* Associated Files:  See list in Program Selection Menu                 *
50 '*                                                                       *
60 '* Purpose:           Simple menu interface for astronomy programs in    *
70 '*                    associated files.                                  *
80 '*                                                                       *
90 '* Programmer:        Martin E. Morrison                                 *
100 '*                                                                       *
110 '* Versions:          1.0   85-11-17                                     *
120 '*                                                                       *
130 '* Copyright:         None (public-domain software).                     *
140 '*************************************************************************
150 '
160 '========================== INITIALIZATION ================================
170 '
180 REM: KEY OFF:WIDTH 80:SCREEN 0,0,0:COLOR 7,0:CLS
190 REM:CLS
200 '
210 '=======================PROGRAM SELECTION MENU ============================
220 '
230 PRINT "                                 PROGRAM SELECTION MENU"
240 PRINT
250 PRINT " (1) HALLEY.BAS:  Computes ephemeris of Comet Halley for any date"
260 PRINT " (2) SUNNY .BAS:  Computes time of sunrise, sunset, and twilight"
270 PRINT " (3) PRECES.BAS:  Computes rigorous precession of any coordinates"
280 PRINT " (4) ADDMAG.BAS:  Computes the combined magnitude of two bodies"
290 PRINT " (5) INTERP.BAS:  Interpolates values in an ephemeris"
300 PRINT " (6) CALJD .BAS:  Converts between civil date and Julian date"
310 PRINT " (7) JDCAL .BAS:  Converts between Julian date and civil date"
320 PRINT " (8) GMST  .BAS:  Calculates sidereal time for Greenwich meridian"
330 PRINT " (9) ALTAZ .BAS:  Calculates altitude and aximuth of a star"
340 PRINT "(10) LENGTH.BAS:  Computes length of stay within 1 AU for any comet"
350 PRINT "(11) ANGULR.BAS:  Computes angular separation of two objects"
360 PRINT "(12) SUNSHI.BAS:  Computes the hours of sunshine for a place"
370 PRINT "(13) LENS  .BAS:  Computes the curves on an aplanatic lens"
380 PRINT "(14) LUNAR .BAS:  Determines heights of lunar features from photos"
390 PRINT "(15) PHOTOM.BAS:  Reduces photometric observations of an object"
400 PRINT "(16) MOONS .BAS:  Calculates the times of new and full moons"
410 PRINT "(17) SHUTTR.BAS:  Computes shutter speeds for astrophotographs"
420 PRINT "(18) WAVEL .BAS:  Calculates wavelengths of lines in a spectrum"
430 PRINT "(19) GREGOR.BAS:  Generates a perpetual Gregorian calendar"
440 PRINT "(20) KEPLER.BAS:  Solves Kepler's equation in orbit computation"
450 PRINT
460 INPUT "PRESS <RETURN> WHEN READY... ",CONTINUE$ : REM: CLS
470 PRINT "(21) HELIAC.BAS:  Calculates heliacal risings and settings"
480 PRINT "(22) SAROS .BAS:  Computes the saros number for solar eclipses"
490 PRINT "(23) XYZ   .BAS:  Computes the X, Y, and Z coordinates of the Sun"
500 PRINT "(98) RETURN TO TOP OF PROGRAM SELECTION MENU"
510 PRINT "(99) EXIT FROM PROGRAM SELECTION MENU"
520 PRINT
530 PRINT
540 '
550 '============================INPUT ROUTINE=================================
560 '
570 INPUT "INPUT SELECTION NUMBER... ",SELECTION%
580 IF SELECTION%=98 THEN  GOTO 230   'Return to Program Selection Menu
590 IF SELECTION%=99 THEN  END    'Exit
600 ON SELECTION% GOSUB 650,660,670,680,690,700,710,720,730,740,750,760,770,780,790,800,810,820,830,840,850,860,870
610  GOTO 230                     'Input exceeds number of selections
620 '
630 '=========================CHAIN TO PROGRAMS================================
640 '
650  CHAIN "HALLEY.BAS"
660  CHAIN "SUNNY .BAS"
670  CHAIN "PRECES.BAS"
680  CHAIN "ADDMAG.BAS"
690  CHAIN "INTERP.BAS"
700  CHAIN "CALJD .BAS"
710  CHAIN "JDCAL .BAS"
720  CHAIN "GMST  .BAS"
730  CHAIN "ALTAZ .BAS"
740  CHAIN "LENGTH.BAS"
750  CHAIN "ANGULR.BAS"
760  CHAIN "SUNSHI.BAS"
770  CHAIN "LENS  .BAS"
780  CHAIN "LUNAR .BAS"
790  CHAIN "PHOTOM.BAS"
800  CHAIN "MOONS .BAS"
810  CHAIN "SHUTTR.BAS"
820  CHAIN "WAVEL .BAS"
830  CHAIN "GREGOR.BAS"
840  CHAIN "KEPLER.BAS"
850  CHAIN "HELIAC.BAS"
860  CHAIN "SAROS .BAS"
870  CHAIN "XYZ   .BAS"
880  END