˙ 15,10: ˙ƒ 10 „+˘ " ******************************"+˘ " * *"+(˘ " * P L A N E T S *"+2˘ " * *"+<˘ " * A programme for the U.K. *"+F˘ " * *"+P˘ " * Einstein User Group *"+Z˘ " * *"+d˘ " * by *"+n˘ " * *"+x˘ " * P.W.H. Moon *"+‚˘ " * *"+Œ˘ " * Version 1.1 28 May 1986 *"+–˘ " * *"+ ˘ " * *"+Ş˘ " * (Xtal BASIC) *"+´˘ " * *"+ž˘ " ******************************"Č:ҏ I~1 r 2500:› I܄ć¤ SCREEN MESSAGEđ˙ 3,6: ˙ƒ 6ú„&˘ " PLANETARY MOTION"&˘ " ________________"˘/"˘ " To a reasonably close approximation,"0,˘ "the planets all revolve in circles with"-6˘ "the Sun as their centre. This makes"/@˘ "them appear to move slowly in the same".J˘ "direction at different speeds against"-T˘ "the background of fixed stars in the"&^˘ "night sky as seen from Earth."h˘/r˘ " Because of the Earth's own movement"/|˘ "round the Sun, the apparent motions of"-†˘ "the planets are not steady; at times".˘ "they reverse their apparent direction"0š˘ "of movement relative to the fixed stars"¤˘ "as seen from Earth."Ž˘-¸˘ " This programme plots the apparent",¢ "position of any planet as seen from"%̢ "Earth over a period of time."Ö˘'ࢠ" Press space bar to go on." ęA$~ä$ô„ţ I~1 r 3:˘:› I-˘ "The scale of the display is shown by",˘ "a bar 1 Astronomical Unit (A.U.) in".˘ "length, which is the mean size of the" &˘ "Earth's orbital radius."0˘,:˘ "If you include on the system tracks"-D˘ "the screen dump routine published in"+N˘ "Newsletter No.1 (page 24), you can"X˘ "print the result."b˘.l˘ "WARNING:- The programme will crash if".v˘ "you ask for a dump but don't have the")€˘ "machine code for the screen dump"Š˘ "on your system tracks." ”˘:˘:˘'ž˘ " Press space bar to go on." ¨A$~ä$˛„ź˙ 1,3: ˙ƒ 3Ć„OФ EARTH ORBIT RADIUS, ANGULAR VELOCITY, AND PHASE ANGLE FOR STARTING PLOT.'ÚRE~149.6: OMEGE~0.0172024: EPS~1.5%ä‡ "Mercury",0.071408,57.95,2.2,2$î‡ "Venus",0.027963,108.11,2.7,4$ř‡ "Mars",0.0091461,227.84,4.0,6'‡ "Jupiter",0.0014503,778.14,10,10' ‡ "Saturn",0.00058940,1427.0,17,20'‡ "Uranus",0.00020467,2870.3,32,30+ ‡ "Neptiune",0.0001043920,4999.9,64,45&*‡ "Pluto",0.0000972667,5909,64,704˘ " M E N U ">˘ " _______"H˘R˘ "(1) Mercury"\˘ "(2) Venus"f˘ "(3) Mars"p˘ "(4) Jupiter"z˘ "(5) Saturn"„˘ "(6) Uranus"Ž˘ "(7) Neptune"˜˘ "(8) Pluto"˘˘Ź˘-ś˘ " or exit from the programme (9)" Ŕ˘:˘:˘/Ę” "Input a number for your choice ";CHOICEÔ“ CHOICE ~ 9 s 1400)Ţ“ CHOICE } 0 z CHOICE 9 s 1000 970č˘:˘-ň˘ "FOR HOW MANY DAYS WOULD YOU LIKE THE"0ü” "SIMULATION TO RUN (DEFAULT 1500)";NDAYS$“ NDAYS$ } "" s 1060NDAYS~1500 ‘ 1070$NDAYS~Ü(NDAYS$).˘68˘ "DO YOU WANT A SCREEN DUMP AFTER THE DISPLAY ?"1B” "ENTER Y OR N AND READY PRINTER IF Y ";YN$L˙‚ 15,4 : ˙ƒ 4 V˙ 15,4`„j˙‡ 120,96t˙€ u5,0 r 5,0~˙€ 0,u5 r 0,5ˆ˘@ 22,12,"E"’ I~ 1 r CHOICE œŁ PLANET$,OMEGP,RP,SCALEF,SŚ› I°§şAU~RExSCALEFĢ@ 30,1;PLANET$Î˙€ 120uAU,u93 r 120,u93Ř˙€ 120uAU,u96 r 120uAU,u90â˙€ 120,u96 r 120,u90ě˘@32,22;"1 A.U."öRE~RExSCALEF: RP~RPxSCALEF DAY~1 r NDAYS p S+ X~RPwČ(OMEGPwDAYtEPS) uREwČ(OMEGEwDAY),Y~RPwŘ(OMEGPwDAYtEPS) u REwŘ(OMEGEwDAY)&¤ CORRECT FOR SCREEN ASPECT RATIO (X~0.75wX 2Ť X,Y <› DAYF“ YN$}"Y" s 1370 P¸ &E270)Z˘ @ 1,22;" TO RETURN TO MENU" dA$~ä$ n‘ 690 x˙ 15,4‚Žƒ