' Sun Jul 19, 1987 (2230)
' MacMiniMUF
'  Based on MINIMUF3.5 (Rose, QST, Dec.1982, pp 36-38.)
' Modified for Macintosh by J.S. Weaver, KA2OVS
'  (5 Sayles St., Alfred, NY 14802)
'  All commercial rights reserved.

   DEF FNSS(F)=-94.43+F*(1.6031+F*(-0.002189+5.20244e-315*F))
   DEF FNFlux(S)=64.2+S*(0.7343+0.000829*S)
   DIM MUF(24),Rect%(3)
   GOSUB SetUp
   ON MENU GOSUB DoMenu
   MENU ON
   ON <0x43,0x07> GOSUB DoDialog
   <0x43,0x07> ON
   
Idle:                                                        ' Main idle loop
   GOTO Idle

DoMenu:                                                    ' Menu handler
   Nmenu=MENU(0)
   IF Nmenu<>1 GOTO Nope
   Nitem=MENU(1)
   ON Nitem GOTO DoHelp,Nope,DoQuit
Nope:                                                        ' Invalid choices land here
   MENU
   RETURN
DoHelp:                                                    ' Help screen page 1
   MENU
   WINDOW 2
   WINDOW OUTPUT 2
   Page%=1
   CALL Helper(Page%)
   RETURN
DoQuit:                                                     ' Exit program
   MENU
   END

DoDialog:                                                 ' Dialog handler
   Act=<0x43,0x07>(0)
   ON Act GOTO DoButton,NewField,Nada,Nada,Nada,DoRet,DoTab
Nada:                                                       ' Invalid choices land here
   RETURN
DoButton:
   Nbutton=<0x43,0x07>(1)
   IF Nbutton=1 THEN                                ' "GO" button
      GOTO DoCalcs
   ELSEIF Nbutton=2 THEN                         ' "SSN" button
      Bflag=2
      <0x40,0x07> 2,2
      <0x40,0x07> 3,1
   ELSEIF Nbutton=3 THEN                         ' "Flux" button
      Bflag=3
      <0x40,0x07> 2,1
      <0x40,0x07> 3,2
   ELSEIF Nbutton=4 THEN                         ' "Quit" button
      END
   ELSEIF Nbutton=5 THEN                         ' "More" button
      Page%=Page%+1
      IF Page%>2 THEN Page%=1
      CALL Helper(Page%)
   ELSEIF Nbutton=6 THEN                         ' "OK" button
      WINDOW 1
      WINDOW OUTPUT 1
      CALL <0x13,0x07>(VARPTR(Rect%(0)))
   END IF
   RETURN
NewField:                                                ' Moved to new edit field
   Efield=<0x43,0x07>(2)
   GOSUB DoFlux                                      ' Update SSN or Flux
   RETURN
DoRet:
   IF WINDOW(0)=1 THEN GOTO DoCalcs    ' Main screen <Return>
   IF WINDOW(0)=2 THEN                           ' Help screen <Return>
      WINDOW 1
      WINDOW OUTPUT 1
      CALL <0x13,0x07>(VARPTR(Rect%(0)))
   END IF
   RETURN
DoTab:                                                        ' Tab to next edit field
   IF Efield<8 THEN Efield=Efield+1 :ELSE Efield=1
   IF Bflag=2 AND Efield=4 THEN Efield=5
   IF Bflag=3 AND Efield=3 THEN Efield=4
   GOSUB DoFlux
   RETURN


DoCalcs:                                                   ' Calculate MUF for this date
   GOSUB DoFlux                                      ' Update SSN or Flux
   Month=VAL(EDIT$(1))                          ' Get current parameter values
   Day=VAL(EDIT$(2))
   SSN=VAL(EDIT$(3))
   Lat1=VAL(EDIT$(5))
   Long1=VAL(EDIT$(6))
   Lat2=VAL(EDIT$(7))
   Long2=VAL(EDIT$(8))
DoMUF:
   CALL <0x2f,0x07>(VARPTR(Rect%(0)))    ' Set up graphics area
   CALL <0x1e,0x07> (250,10):  CALL <0x1e,0x00> (250,280)
   CALL <0x20,0x07> (490,280):  CALL <0x20,0x00> (490,10)
   FOR F=0 TO 30 STEP 10
      Y=280-8*F
      CALL <0x22,0x07> (230,Y+5):  PRINT USING "##"; F;
      CALL <0x1f,0x07> (250,Y):  CALL <0x1f,0x00> (255,Y)
      CALL <0x21,0x07> (490,Y):  CALL <0x21,0x00> (485,Y)
      NEXT F
   CALL <0x19,0x07> (215,70):  PRINT "MUF";
   CALL <0x1a,0x07> (210,85):  PRINT "(MHz)"
   FOR H=0 TO 24 STEP 6
      X=250+10*H
      CALL <0x22,0x07> (X,280):   CALL <0x22,0x00> (X,275)
      CALL <0x24,0x07> (X-9,297):   PRINT USING "##"; H;
      NEXT H
   CALL <0x1a,0x07> (395,300):  PRINT "UT";
   Mflag=0                                                ' Signals start of line segment
   FOR Hour=0 TO 24
      CALL MUFFER (Lat1,Long1,Lat2,Long2,Month,Day,Hour,SSN,MUF)
      MUF(Hour)=MUF
      IF MUF<34 THEN                                ' Plot the MUF value
         IF Mflag=0 THEN
            CALL <0x1c,0x07> (250+10*Hour,280-8*MUF)
            Mflag=1
         ELSE
            CALL <0x1c,0x07> (250+10*Hour,280-8*MUF)
         END IF
      ELSE
         Mflag=0
      END IF
      NEXT Hour
   CALL <0x43,0x07> (10,155)                        ' Print table of MUF values
   PRINT "Hour   MUF    Hour   MUF";
   FOR H=0 TO 11
      CALL <0x15,0x07> (10,170+12*H)
      PRINT USING " ##  ###.#      ## ###.#"; H,MUF(H),H+12,MUF(H+12);
      NEXT H
   RETURN

SetUp:                                                    ' Init the program
   <0x9e6a81,0x07>(4)
   <0x9e6a97,0x07>(9)
   WINDOW 2,,(186,22)-(509,336),3        ' Help window
   <0x40,0x07> 5,1,"More",(100,290)-(150,310),1
   <0x40,0x07> 6,1,"OK",(200,290)-(250,310),1
   WINDOW 1,,(1,21)-(511,339),3             ' Main window
   WINDOW OUTPUT 1
   MENU 1,0,1,"Help"                                  ' Setup menu
   MENU 1,1,1,"Help"
   MENU 1,2,0,"-"
   MENU 1,3,1,"Quit"
   D$=DATE$                                             ' Setup edit fields
   CALL <0x1a,0x07> (10,23): PRINT "Date:";
   EDIT FIELD 1,MID$(D$,1,2),(60,10)-(80,25),1
   CALL <0x16,0x07> (93,23): PRINT "/";
   EDIT FIELD 2,MID$(D$,4,2),(110,10)-(130,25),1
   CALL <0x19,0x07> (10,48): PRINT "SS#:";
   <0x40,0x07> 2,2,"",(55,35)-(70,50),3
   Bflag=2
   EDIT FIELD 3,"100",(80,35)-(110,50),1
   CALL <0x1a,0x07> (10,73): PRINT "Flux:";
   <0x40,0x07> 3,1,"",(55,60)-(70,75),3
   EDIT FIELD 4,"",(80,60)-(110,75),1
   CALL <0x19,0x07> (60,95):  PRINT "Lat";
   CALL <0x19,0x07> (100,95): PRINT "Long";
   CALL <0x1a,0x07> (10,112): PRINT "Xmtr:";
   EDIT FIELD 5, "42.3",(50,100)-(90,115),1
   EDIT FIELD 6, "77.8",(95,100)-(135,115),1
   CALL <0x1a,0x07> (10,132): PRINT "Rcvr:";
   EDIT FIELD 7, "43.5",(50,120)-(90,135),1
   EDIT FIELD 8, "72.8",(95,120)-(135,135),1
   <0x40,0x07> 1,1,"Go",(150,10)-(180,30),1
   <0x40,0x07> 4,1,"Quit",(150,40)-(180,60),1
   Efield=1
   Rect%(0)=1:  Rect%(1)=200:  Rect%(2)=300:  Rect%(3)=495
DoFlux:                                                    ' Updates SSN and Flux values
   IF Bflag=2 THEN
      S=VAL(EDIT$(3))
      F=FNFlux(S)
      EDIT FIELD 4,STR$(CINT(F)),(80,60)-(110,75),1
   ELSEIF Bflag=3 THEN
      F=VAL(EDIT$(4))
      S=FNSS(F)
      EDIT FIELD 3,STR$(CINT(S)),(80,35)-(110,50),1
   END IF
   X=FRE("")
   EDIT FIELD Efield
   RETURN
   END
   
SUB MUFFER (Lata,Longa,Latb,Longb,Month,Day,Hour,SSN,MUF) STATIC
' A literal translation of the MINIMUF 3.5 code.
   One=0.99999
   Pi=4*ATN(1):  HalfPi=Pi/2:  TwoPi=2*Pi:  Rads=Pi/180
   Lat1=Rads*Lata:  SLat1=SIN(Lat1):  CLat1=COS(Lat1)
   Lat2=Rads*Latb:  SLat2=SIN(Lat2):  CLat2=COS(Lat2)
   Long2=Rads*Longb:  DLong12=Rads*(Longa-Longb)
   CR12=SLat1*SLat2+CLat1*CLat2*COS(DLong12)
   IF ABS(CR12)>One THEN CR12=One*SGN(CR12)
   SR12=SQR(1-CR12*CR12)
   R12=HalfPi-ATN(CR12/SR12)
   K6=1.59*R12
   IF K6<=1 THEN
      K6=1
      K5=1
      ELSE
      K5=0.5
      END IF
   M9=2.5*R12*K5
   IF M9<HalfPi THEN M9=SIN(M9) :ELSE M9=1
   M9=(1+2.5*M9*SQR(M9))*(1+SSN/250)
   M9=M9*(1+0.1*(1-SGN(Lat1)*SGN(Lat2)))
   ElongSun=0.0172*(10+(Month-1)*30.4+Day)
   DecSun=0.409*COS(ElongSun)
   HA0Sun=12+0.13*(SIN(ElongSun)+1.2*SIN(2*ElongSun))
   MUF=100
   A=(SLat1-SLat2*CR12)/(CLat2*SR12)
   FOR K1=1/(2*K6) TO 1-1/(2*K6) STEP 0.9999-1/K6
      B=R12*K1
      C=SLat2*COS(B)+CLat2*SIN(B)*A
      Lat0=ATN(C/SQR(1-C*C))
      D=(COS(B)-C*SLat2)/(CLat2*SQR(1-C*C))
      IF ABS(D>One) THEN D=One*SGN(D)
      Long0=Long2+SGN(SIN(DLong12))*(HalfPi-ATN(D/SQR(1-D*D)))
      IF Long0<0 THEN Long0=Long0+TwoPi
      IF Long0>=TwoPi THEN Long0=Long0-TwoPi
      K8=3.82*Long0+HA0Sun
      IF K8>24 THEN K8=K8-24
      C0=COS(Lat0+DecSun)
      IF C0<=-0.26 THEN  K9=0:  G0=0:  GOTO L1770
      K9=(-0.26+SIN(DecSun)*SIN(Lat0))/(COS(DecSun)*COS(Lat0)+0.001)
      K9=12-ATN(K9/SQR(ABS(1-K9*K9)))*7.63944
      T=K8-K9/2
      IF T<0 THEN T=T+24
      T4=K8+K9/2
      IF T4>24 THEN T4=T4-24
      C0=ABS(C0)
      T9=9.7*C0^9.6
      IF T9<0.1 THEN T9=0.1
      G8=Pi*T9/K9
      IF T4<T THEN L1680
      IF (Hour-T)*(T4-Hour)>0 THEN L1690 :ELSE L1820
L1680:
      IF (Hour-T4)*(T-Hour)>0 THEN L1820
L1690:
      IF T>Hour THEN T6=Hour+24 :ELSE T6=Hour
      G9=Pi*(T6-T)/K9
      G0=SIN(G9)+G8*(EXP((T-T6)/T9)-COS(G9))
      G7=G8*(EXP(-K9/T9)+1)*EXP((K9-24)/2)
      IF G0<G7 THEN G0=G7
      GOTO L1770
L1820:
      T6=Hour+12*(1+SGN(T4-Hour))*SGN(ABS(T4-Hour))
      G0=G8*(EXP(-K9/T9)+1)*EXP((T4-T6)/2)
L1770:
      G0=C0*G0/(1+G8*G8)
      G2=M9*SQR(6+58*SQR(G0))
      G2=G2*(1-0.1*EXP((K9-24)/3))
      G2=G2
      G2=G2*(1-0.1*(1+SGN(ABS(SIN(Lat0))-COS(Lat0))))
      IF MUF>G2 THEN MUF=G2
      NEXT K1
   END SUB

SUB Helper (Page%) STATIC                    ' Prints help screens
   CLS
   ON Page% GOTO Page1,Page2
   EXIT SUB
Page1:
   PRINT "                          MacMiniMUF"
   PRINT "                                 by"
   PRINT "                  J. Scott Weaver, KA2OVS"
   PRINT "             5 Sayles St., Alfred, NY 14802"
   PRINT "                             7/19/87
   PRINT "            (All commercial rights reserved.)"
   PRINT
   PRINT "MacMiniMUF is a F-region propagation model useful"
   PRINT "from 2 to 50 MHz and ranges from 250 to 6000"
   PRINT "miles.  MacMiniMUF is based on MINIMUF 3.5.  (See:"
   PRINT "Rose, R. B., K6GKU, 'MINIMUF:  A Simplified MUF-"
   PRINT "Prediction Program for Microcomputers', QST, Dec."
   PRINT "1982, pp. 36-38.)"
   PRINT
   PRINT "Note:  the Basic Compiler and Runtime Modules"
   PRINT "are Copyright1986 by the Microsoft Corporation."
   EXIT SUB
Page2:
   PRINT "                           MacMiniMUF"
   PRINT
   PRINT "Instructions:"
   PRINT "Use mouse and keyboard to enter data into fields."
   PRINT "TAB advances to next field.  Radio buttons select"
   PRINT "solar input as Sunspot number or 2800MHz flux."
   PRINT "GO button or Return key starts calculations.  QUIT"
   PRINT "(button or menu choice) exits program."
   PRINT
   PRINT "Limits:    -90 <= Lat <= 90     -360 < Long < 360"
   PRINT
   PRINT "Warning:  No input error checking is done!"
   END SUB