100 REM ARCHIMEDES SPIRAL
110 REM 
120 REM 
130 REM 
140 GRAPHICS 8+16:SETCOLOR 2,0,0
150 XP=144:XR=4.71238905:XF=XR/XP
160 FOR ZI=-64 TO 64
170 ZT=ZI*2.25:ZS=ZT*ZT
180 XL=INT(SQR(20736-ZS)+0.5)
190 FOR XI=0-XL TO XL
200 XT=SQR(XI*XI+ZS)*XF
210 YY=(SIN(XT)+SIN(XT*3)*0.4)*56
220 X1=XI+ZI+160:Y1=90-YY+ZI
230 TRAP 250:COLOR 1:PLOT X1,Y1
240 COLOR 0:PLOT X1,Y1+1:DRAWTO X1,191
250 NEXT XI:NEXT ZI
260 GOTO 260