Here is a compact Sine calculator script for your perusal which is fairly accurate and quick.
No lookup or FPU needed
rem Parabola Sine Approximation
rem For explanation of method visit:-
rem
http://lab.polygonal.de/2007/07/18/fast-and-accurate-sinecosine-approximation/rem uses 1/10 degree as input, output 1/10000, accuracy varies about 1/1000
rem deg/180 = rad/pi, sine < 10 deg approx = rad
rem rad= deg*pi/180
rem 1st approx. s= 4d/180(1-d/180)
rem refined by Q= 225/1000 ((s*s) - s) + s
s=0
for i = 5 to 50 step 10
d=i*15 +3
if d < 100 then
r= d*3550/2034
print, "Sine(",d/10,".",d %10,") = 0. 0",r
else
rem 1st approximation
s= (1800-d)*4/18*d/18
rem refinement
k=s/40*9
p=s-10000
q=p/100*k /100
rem print "d,r,Sine-S ",d,r,s,q
print, "Sine(",d/10,".",d %10,") = 0.",q+s
rem print "[adjustment] s,K,P q ", s,k,p,q,(q+s)
endif
next i
end
