Here's a short routine that will draw Archimedean spirals on your screen. When run, the program asks for the number of degrees it should turn after each line, usually a number between 45 and 190. It really shows off when somebody asks what your PC or PCjr can do.
Eric S. Kramer
Thank you for the contribution. (The program requires a PCjr with Cartridge BASIC or a PC with BASICA and the color/graphics adapter.)
ME 50 SCREEN 1:CLS
IC 105 LINE INPUT"DEGREES=";D$:D=VAL(D$)
BP 106 CLS
BM 140 D=D/57.29578:'CONVERT DEGREES TO R
ADIANS
DC 150 PSET (130,96),1
JP 160 FOR R=0 TO 100 STEP D
MM 170 X=R*COS(R):X=X+130:Y=R*SIN(R):Y=Y*
.7+96
IO 210 LINE -(X,Y),3
C0 220 NEXT R
LD 230 PAINT (100,1),3