10 IFPAGE<&E00THEN50
   20 *K.0P.'"ƒMoving down....."|L|M*T.|MF.A%=0TO(TOP-PA.)S.4:A%!&E00=A%!PA.:N.|MPA.=&E00|MO.|MDEL.10,40|MRUN|M
   30 *FX138,0,128
   40 END
   50 *FX200,3
   60 CLEAR
   70 MODE7
   80 RESTORE430
   90 PROCSETUP
  100 PROCWORK
  110 IFANARD%=1THEN120:ELSE140
  120 MODE1
  130 PROCANARD
  140 GOTO60
  150 DEFPROCSETUP
  160 OL%=0
  170 UP%=3
  180 VDU23;11;0;0;0;0;
  190 VDU129,157,135,141
  200 PRINTTAB(12,0)"Complex Numbers."
  210 VDU129,157,135,141
  220 PRINTTAB(12,1)"Complex Numbers."
  230 VDU129,157,135
  240 PRINTTAB(8,2)"(c) 1989 Stephen Bodman."
  250 VDU28,0,23,39,3
  260 VDU133,141
  270 PRINTTAB(14,0)"Menu"
  280 VDU133,141
  290 PRINTTAB(14,1)"Menu"
  300 FORA=5TO14STEP1
  310 READOPT$
  320 PRINTTAB(3,A);OPT$
  330 NEXT
  340 PRINTTAB(1,17)"‚Use the space to toggle the bar to "
  350 PRINTTAB(4,18)"‚the option you want then hit "
  360 PRINTTAB(14,19)"‚<RETURN>"
  370 PROCDOWN(13)
  380 REPEAT
  390 X=INKEY(0)
  400 UNTILX<>-1
  410 IFX=32THENPROCDOWN(UP%)
  420 IFX=13THENENDPROC:ELSE380
  430 DATAFind root of a number,Add two complex numbers,Subtract two complex numbers,Multiply two complex numbers,Divide two complex numbers,Complex numbers to the power n
  440 DATA Find modulus of a complex number,Find aurgument of a complex number,Draw an Anard diagram,Express in the form r(cosQ+isinQ)
  450 DEFPROCDOWN(U%)
  460 RESTORE430
  470 IFU%=14THENU%=4
  480 U%=U%+1
  490 FORA=1TOU%-4
  500 READOPT$
  510 NEXT
  520 PRINTTAB(0,U%-1)
  530 VDU129,157,135
  540 PRINTTAB(3,U%);OPT$
  550 RESTORE430
  560 IFOL%=14THENOL%=4
  570 OL%=OL%+1
  580 FORA=1TOOL%-4
  590 READOPT$
  600 NEXT
  610 PRINTTAB(0,OL%)"                                  "
  620 PRINTTAB(3,OL%);OPT$
  630 UP%=U%
  640 OL%=U%-1
  650 PRINTTAB(0,4)"                                   "
  660 PRINTTAB(12,1)CHR$(141);"…Menu             "
  670 ENDPROC
  680 DEFPROCWORK
  690 IFUP%=5THENPROCSQR
  700 IFUP%=6THENPROCADD
  710 IFUP%=7THENPROCTAKE
  720 IFUP%=8THENPROCTIMES
  730 IFUP%=9THENPROCDIVIDE
  740 IFUP%=10THENPROCPOWER
  750 IFUP%=11THENPROCMOD
  760 IFUP%=12THENPROCARG
  770 IFUP%=13ANARD%=1:ELSEANARD%=0
  780 IFUP%=14THENPROCEXPRESS
  790 ENDPROC
  800 DEFPROCSQR
  810 CLS
  820 PRINTTAB(3,2)"To find the root of a number."
  830 INPUTTAB(0,7)"‚Please type in a number ",N$
  840 IFRIGHT$(N$,1)="i"THEN910
  850 N=VAL(N$)
  860 IFN<0THEN870:ELSE940
  870 N=SQR(N^2)
  880 PRINT:PRINT"Root =‚";SQR(N);"i"
  890 X=INKEY(1000)
  900 ENDPROC
  910 PRINT:PRINT"Root =ƒSorry I don't know."
  920 X=INKEY(1000)
  930 ENDPROC
  940 PRINT:PRINT"Root =‚";SQR(N)
  950 X=INKEY(1000)
  960 ENDPROC
  970 DEFPROCADD
  980 CLS
  990 PRINTTAB(3,2)"To find the sum of two complex"
 1000 PRINTTAB(5,3)"numbers of the form 'a+bi'"
 1010 PRINT:PRINT"  (a+bi)  +  (c+di)"
 1020 PRINT:INPUT"Value for a ",AA
 1030 INPUT"Value for b ",BA
 1040 PRINT:INPUT"Value for c ",AB
 1050 INPUT"Value for d ",BB
 1060 IFBA<0ORBB<0THEN1120
 1070 IFBA<0ANDBB<0THEN1120
 1080 PRINT:PRINT:PRINT"(";AA;"+";BA;"i) + (";AB;"+";BB;"i)";
 1090 PRINT;"  = ";AA+AB;"+";BA+BB;"i "
 1100 X=INKEY(1000)
 1110 ENDPROC
 1120 IFBA<0THEN1180
 1130 IFBA<0ANDBB<0THEN1160
 1140 PRINT:PRINT:PRINT"(";AA;"+";BA;"i) + (";AB;BB;"i)";
 1150 GOTO1190
 1160 PRINT:PRINT:PRINT"(";AA;BA;"i) + (";AB;BB;"i)";
 1170 GOTO1190
 1180 PRINT:PRINT:PRINT"(";AA;BA;"i) + (";AB;"+";BB;"i)";
 1190 PRINT;"  = ";AA+AB;
 1200 IFBA+BB<0THEN1230:ELSE1210
 1210 PRINT;"+";BA+BB;"i "
 1220 GOTO1100
 1230 PRINT;BA+BB;"i "
 1240 GOTO1100
 1250 DEFPROCTAKE
 1260 CLS
 1270 PRINTTAB(3,2)"To find the difference  of two "
 1280 PRINTTAB(2,3)"complex numbers of the form 'a+bi'"
 1290 PRINT:PRINT"  (a+bi) - (c+di)"
 1300 PRINT:INPUT"Value for a ",AA
 1310 INPUT"Value for b ",BA
 1320 PRINT:INPUT"Value for c ",AB
 1330 INPUT"Value for d ",BB
 1340 IFBA<0ORBB<0THEN1440
 1350 IFBA<0ANDBB<0THEN1440
 1360 IFBA-BB<0THEN1400
 1370 PRINT:PRINT:PRINT"(";AA;"+";BA;"i) - (";AB;"+";BB;"i)";
 1380 PRINT;"  = ";AA-AB;"+";BA-BB;"i "
 1390 GOTO1420
 1400 PRINT:PRINT:PRINT"(";AA;"+";BA;"i) - (";AB;"+";BB;"i)";
 1410 PRINT;"  = ";AA-AB;BA-BB;"i "
 1420 X=INKEY(1000)
 1430 ENDPROC
 1440 PRINT:PRINT:PRINT"(";AA;BA;"i) - (";AB;"+";BB;"i)";
 1450 PRINT;"  = ";AA-AB;
 1460 IFBA-BB<0THEN1490:ELSE1470
 1470 PRINT;"+";BA-BB;"i "
 1480 GOTO1420
 1490 PRINT;BA-BB;"i "
 1500 GOTO1420
 1510 DEFPROCTIMES
 1520 CLS
 1530 PRINTTAB(3,2)"To find the multiple of two complex"
 1540 PRINTTAB(5,3)"numbers of the form 'a+bi'"
 1550 PRINT:PRINT"(a+bi) * (a+bi)"
 1560 PRINT:INPUT"Value of a",A
 1570 INPUT"Value of b",B
 1580 PRINT:INPUT"Value of c",C
 1590 INPUT"Value of d",D
 1600 IFB>0ANDD>0THEN1690:ELSE1610
 1610 IFB<0ANDD<0THEN1670:ELSE1620
 1620 IFB<0THEN1630:ELSE1650
 1630 PRINT:PRINT"(";A;B;"i) * (";C;"+";D;"i)";
 1640 GOTO1700
 1650 PRINT:PRINT"(";A;"+";B;"i) * (";C;D;"i)";
 1660 GOTO1700
 1670 PRINT:PRINT"(";A;B;"i) * (";C;D;"i)";
 1680 GOTO1700
 1690 PRINT:PRINT"(";A;"+";B;"i) * (";C;"+";D;"i)";
 1700 PROCMULTIPLY(2,A,B,C,D)
 1710 X=INKEY(1000)
 1720 ENDPROC
 1730 DEFPROCMULTIPLY(Q,A,B,C,D)
 1740 W=A*C:X=A*D:Y=B*C:Z=B*D
 1750 E=X+Y:F=W-Z
 1760 IFQ=1THENENDPROC:ELSE1770
 1770 IFE>0THEN1790:ELSEIFE=0THEN1810:ELSE1830
 1780 IFE>0THEN1790:ELSEIFE=0THEN1810:ELSE1830
 1790 PRINT;" = ";F;"+";E;"i "
 1800 ENDPROC
 1810 PRINT;" = ";F
 1820 ENDPROC
 1830 PRINT;" = ";F;E;"i "
 1840 ENDPROC
 1850 DEFPROCPOWER
 1860 CLS
 1870 PRINTTAB(3,2)"To raise a complex number to the                  power 'n'"
 1880 PRINTTAB(6,6)"n"
 1890 PRINTTAB(5,7)"i"
 1900 INPUTTAB(3,9)"Value of n ",N
 1910 PRINTTAB(6,12);N
 1920 PRINTTAB(5,13)"i   = ";
 1930 IFNMOD2=0THENPRINT;"1":ELSE1950
 1940 GOTO1960
 1950 PRINT;"-i"
 1960 X=INKEY(1000)
 1970 ENDPROC
 2040 DEFPROCDIVIDE
 2050 CLS
 2060 PRINTTAB(3,2)"To divide two complex numbers of the                  form 'a+bi'"
 2070 PRINT"     (a+bi)"
 2080 PRINT"     ______"
 2090 PRINT"     (c+di)"
 2100 PRINT:INPUT"Value of a",A
 2110 INPUT"Value of b",B
 2120 PRINT:INPUT"Value of c",C
 2130 INPUT"Value of d",D
 2140 IFB<0THEN2150:ELSE2160
 2150 PRINT:PRINT"  ";A;B;"i":GOTO2170
 2160 PRINT:PRINT"  ";A;"+";B;"i"
 2170 PRINT" ______  ="
 2180 IFD<0THEN2190:ELSE2200
 2190 PRINT"  ";C;D;"i":GOTO2210
 2200 PRINT"  ";C;"+";D;"i"
 2210 G=SQR(D^2)
 2220 PROCMULTIPLY(1,A,B,C,G)
 2230 H=E:I=F
 2240 PROCMULTIPLY(1,C,D,C,G)
 2250 J=E:K=F
 2260 IFH<0THEN2310
 2270 PRINTTAB(13,14);I;"    ";H
 2280 PRINTTAB(12,15)"____ + ____i"
 2290 PRINTTAB(13,16);K;"   ";K
 2300 GOTO2330
 2310 PRINTTAB(13,14);I;"    ";H
 2320 GOTO2280
 2330 X=INKEY(1000)
 2340 ENDPROC
 2350 DEFPROCMOD
 2360 CLS
 2370 PRINT:PRINT"To find the moduls of a complex number            of the form 'a+bi'"
 2380 PRINT:INPUT"Value for a ",A
 2390 INPUT"Value for b ",B
 2400 IFB<0THEN2410:ELSE2420
 2410 PRINT:PRINT"Moduls of ";A;B;"i = ";
 2420 PRINT:PRINT"  Moduls of ";A;"+";B;"i =";
 2430 MD=SQR((A^2)+(B^2))
 2440 PRINT;" ";MD
 2450 X=INKEY(1000)
 2460 ENDPROC
 2470 DEFPROCARG
 2480 CLS
 2490 PRINT"  To find the argument of a complex            number of the form 'a+bi'"
 2500 PRINT:INPUT"Value for a ",A
 2510 INPUT"Value for b ",B
 2520 IFA>0THENPROCPOSITIVE:ELSEPROCNEGATIVE
 2530 IFB>0THEN2540:ELSE2560
 2540 PRINT:PRINT"    arg(";A;"+";B;"i) = ";ARG;" rads"
 2550 GOTO2570
 2560 PRINT:PRINT"    arg(";A;B;"i) = ";ARG;" rads"
 2570 X=INKEY(1000)
 2580 ENDPROC
 2590 DEFPROCPOSITIVE
 2600 ARG=ATN(B/A)
 2610 IFB<0THEN2620:ELSEENDPROC
 2620 ARG=-ARG
 2630 ENDPROC
 2640 DEFPROCNEGATIVE
 2650 IFB>0THENR=-B:ELSER=B
 2660 ARG=PI-(ATN(R/A))
 2670 IFB<0THEN2680:ELSEENDPROC
 2680 ARG=-ARG
 2690 ENDPROC
 2700 MODE1
 2710 DEFPROCANARD
 2720 CLS
 2730 COLOUR1
 2740 PRINTTAB(0,0)"Complex Numbers (c) 1989 Stephen Bodman"
 2750 COLOUR2
 2760 PRINTTAB(2,2)"To draw an anard diagram for a complex       number of the form 'a+bi'."
 2770 INPUTTAB(2,6)"Value of a",A
 2780 INPUTTAB(2,7)"Value of b",B
 2790 IFB>0THEN2800ELSE2820
 2800 PRINT:PRINT"(";A;"+";B;"i)"
 2810 GOTO2830
 2820 PRINT:PRINT"(";A;B;"i)"
 2830 PROCSCALE
 2840 VDU29,800;500;
 2850 MOVE0,250
 2860 DRAW0,-250
 2870 MOVE250,0
 2880 DRAW-250,0
 2890 MOVE0,0
 2900 DRAWX%,Y%
 2910 PRINTTAB(0,28)"Hit a key to return to menu."
 2920 A$=GET$
 2930 ENDPROC
 2940 DEFPROCSCALE
 2950 C=SQR(A^2):D=SQR(B^2)
 2960 IFC>DTHENPROCC:ELSEPROCD
 2970 ENDPROC
 2980 DEFPROCC
 2990 IFA<0THENX%=-200:ELSEX%=200
 3000 Y%=B*(200/C)
 3010 ENDPROC
 3020 DEFPROCD
 3030 IFB<0THENY%=-200:ELSEY%=200
 3040 X%=A*(200/D)
 3050 ENDPROC
 3060 DEFPROCEXPRESS
 3070 CLS
 3080 PRINT"      Express a+bi in the form                        r(cosQ+isinQ)"
 3090 PRINT:INPUT"Value for a ",A
 3100 INPUT"Value for b ",B
 3110 S=SQR((A^2)+(B^2))
 3120 IFA>0THENPROCPOSITIVE:ELSEPROCNEGATIVE
 3130 IFB<0THEN3170
 3140 PRINTA;"+";B;"i =":PRINT:PRINT"      ";S;"(cos";ARG;"+isin";ARG;") "
 3150 X=INKEY(5000)
 3160 ENDPROC
 3170 PRINTA;B;"i =":PRINT:PRINT"      ";S;"(cos";ARG;"+isin";ARG;") "
 3180 GOTO 3150