Drawing Inductors

The task:

Making a subroutine for drawing an inductor with n parts, at a length of twips and at an angle in rad.

SMOOTH ON
CLS 15, 0
BACK {CLS 15,0}
PEN 0
DOUBLE
REPORT 2,  "DRAWING INDUCTOR"
NORMAL
A=-PI/16
AA=0
DATA 1000, 6000, 12000, 0
FOR M=1000 TO 8000 STEP 2000
MOVE 2000+AA, 6000+M
INDUCTOR(4, M, 0+A)
INDUCTOR(8, M, -PI/2+A)
INDUCTOR(6, M, -PI+A)
INDUCTOR(3, M, PI/2+A)
A+=PI/3
AA+=NUMBER
NEXT
PUSH KEY$
DROP
SUB INDUCTOR(PARTS, LE, A)
	LOCAL SINGLE M=LE/6000*240
	LOCAL SINGLE B=LE/(PARTS+4)*.4
	LOCAL SINGLE C=B-20*PARTS*LE/6000
	WHILE LE>(4*B+2*PARTS*(B-C))
		C-=15
		IF C<M THEN B*=1.2: c=B/1.3
	END WHILE
	WIDTH 3 {DRAW ANGLE A, B}
	STEP ANGLE A, B
	FOR I=1 TO PARTS
		ARC(TRUE, B, A)
		STEP ANGLE A, B
		STEP ANGLE A, -C
		ARC(FALSE, C, A)
		STEP ANGLE A, B-C	
	NEXT
	ARC(TRUE, B, A)
	STEP ANGLE A, B
	WIDTH 3 {DRAW ANGLE A, B}
END SUB
SUB ARC(UP AS BOOLEAN, AR AS SINGLE, ARG AS SINGLE)
	LOCAL KK=-ARG, K=KK
	WIDTH 3 {
		IF UP ELSE K+=PI
		CIRCLE AR, 1, PEN, 0-K, PI-K;
	}
END SUB